Master of Veterinary Science

Transcription

1 GROSS, BIOMETRICAL AND HISTOMORPHOLOGICAL STUDIES ON VARIOUS ORGANS OF THE DIGESTIVE SYSTEM OF FRIZZLED FEATHER AND NAKED NECK FOWLS (Gallus gallus domesticus) A THESIS SUBMITTED TO THE ANAND AGRICULTURAL UNIVERSITY IN THE PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF THE DEGREE OF Master of Veterinary Science IN VETERINARY ANATOMY & HISTOLOGY BY MAL TRUPTIBEN BHARATBHAI B. V. Sc. & A. H. (Reg. No ) DEPARTMENT OF VETERINARY ANATOMY & HISTOLOGY COLLEGE OF VETERINARY SCIENCE & ANIMAL HUSBANDRY ANAND AGRICULTURAL UNIVERSITY ANAND (GUJARAT) 2016

2 Dedicated To My Beloved Parents and Respected Guide

3 Abstract

4 ABSTRACT GROSS, BIOMETRICAL AND HISTOMORPHOLOGICAL STUDIES ON VARIOUS ORGANS OF THE DIGESTIVE SYSTEM OF FRIZZLED FEATHER AND NAKED NECK FOWLS (Gallus gallus domesticus) Name of student Mal Trupti B. Major Advisor Dr. K. M. Panchal DEPARTMENT OF ANATOMY & HISTOLOGY COLLEGE OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY ANAND AGRICULTURAL UNIVERSITY ANAND, GUJARAT, INDIA The present study entitled Gross, Biometrical and Histomorphological Study on Various Organs of The Digestive System of Frizzled feather and Naked neck Fowls (Gallus gallus domesticus) was carried out at the Department of Veterinary Anatomy and Histology, College of Veterinary Science & A. H., Anand Agricultural University, Anand, Gujarat. For this study, Six healthy adult birds (aging at 14 th weeks) Frizzled feather and Naked neck breeds were used for the gross, biometrical and histomorphological evaluations. The biometrical measurements of the different parameters of the digestive system include tongue, oesophagus, crop, proventriculus, gizzard, small intestine viz., duodenum, jejunum, ileum and large intestine includes double caeca and colorectum, liver and pancreas were recorded with the help of the digital weighing balance, Vernier calipers and nonstretchable thread. The 6 th paraffin sections were stained with Haematoxylin and

5 Abstract Eosin Stain for routine examination of histomorphology of the above mentioned organs of both the breeds. The tongue of the Frizzled feather and Naked neck fowl, was brownish in color, triangular in shape with a pointed apex, a wide base and short body. The body of tongue was attached ventrally with the floor of lower beak and its mucosa was comparatively thinner and smooth. Dorsal surface of was marked by a fade median groove and at the level of root, there was a single row of caudally directed papillae. The entoglossal process of hyoid bone supported the root of tongue of Frizzled feather and Naked neck fowls. There was no significant difference (P>0.05) between the length of the tongue of Frizzled feather (2.40±0.68 cm) and Naked neck (2.15± 0.09 cm). The mucosal epithelium of tongue was composed of keratinized stratified squamous epithelium which was thick on the dorsum linguae in both the breeds under study. The esophagus in both the breeds was long, narrow and straight collapsible tube extended from the pharynx to proventriculus. It was composed of two parts; cervical part and thoracic part separated by its own diverticulum called crop. Cervical part was comparatively longer than thoracic part in both the breeds. The mean ± SE value of total length of esophagus of Frizzled feather and Naked neck was ± 0.73 cm and ± 0.56 cm. The external diameter was 2.10 ± 0.15 cm and 1.91±0.18 cm (cervical part), 1.91±0.13 cm and 1.75 ± 0.11cm (thoracic part), respectively. The esophageal wall consists of usual layers of tubular digestive organs, i.e. mucosa, submucosa, musculosa and adventitia or serosa within outward. The mucosa was formed of stratified squamous epithelium with about 7-8 longitudinal folds of ii

6 Abstract various shapes. The submucus glands or esophageal glands were observed in both, the cervical and the thoracic parts of esophagus. The crop was situated at right ventrolateral aspect to the thoracic inlet in both the breeds. The mucous glands were not found in crop. The proventriculus was small, elongated, spindle shaped and thick walled tube, which was connected anteriorly with esophagus and posteriorly with gizzard. There was a constricted area between the proventriculus and gizzard called isthmus. The mean ± SE value of length of proventriculus of Frizzled feather and Naked neck fowl was 4.15±0.14 cm and 3.83±0.10 cm, respectively. The mucosa of proventriculus showed tall gastric ridges lined by simple columnar epithelium. Lamina propria was having the superficial mucosal glands. Submucosa was full of large submucosal glands/ proventricular glands. The gizzard was much larger and more muscular than the proventriculus and connected with the proventriculus. It was biconvex and laterally flat in shape, dark reddish to brown in colour. The mean ± SE value of length of gizzard in Frizzled feather and Naked neck were 6.00± 0.46 cm and 5.85± 0.27 cm, respectively. The mean width of gizzard of Frizzled feather and Naked neck were 4.25±0.22 cm and 3.11±0.45 cm, respectively. The mean ± SE value of periphery measured at the greater curvature of gizzard in Frizzled feather and Naked neck were 7.43±0.19 cm and 6.25±0.38 cm, respectively. The gizzard was characterized by a keratinized layer of mucosa called cutical. Below this layer, the mucosal glands were present. Muscularies mucosae was not present. The smooth muscle bundles were separated by connective tissue septae giving mosaic appearance to the muscular layer. iii

7 Abstract The small intestine was distinguished into three main parts; duodenum, jejunum and ileum. The duodenum begins at the end of gizzard and forms an elongated loop had proximal descending and distal ascending parts. There was no clear demarcation between the jejunum and ileum. The jejunum was pale brownish to reddish in color and was longest part of small intestine. It was a coiled structure and the coils were suspended by the fold of mesentery. Meckel s diverticulum appeared as a small projection on the free border of the terminal point of jejunum. The ileum was comparatively smaller and straight than other part of intestine in both the breeds. The mean ± SE value of length of duodenum, jejunum and ileum in Frizzled feather was 24.0±0.99 cm, 98.2±4.06 cm, 18.7±0.77 cm, respectively. The mean ± SE value of length of duodenum, jejunum and ileum in Naked neck was 21.5±0.59 cm, 87.33±5.10 cm and 20.0±0.96 cm, respectively. The mucosal villi in the duodenum were more in height as compared to that of jejunum and ileum. The intestinal glands or crypts of Lieberkuhn were present throughout the mucosa of intestine. The goblet cells were numerous in ileum than in duodenum. The duodenal glands could not be found in both the breeds. The right and left caeca, blind tubes originated at the ileocolic junction, were greyish black in color. The mean ± SE value of length of caecum of Frizzled feather and Naked neck fowl was 17.0±1.15 cm and 16.6±0.69 cm, respectively. The colo-rectum was the terminal part of the large intestine, extended between the ileo-cecal junction and terminated into the cloacal chamber, coprodeum. The mean ± SE value of length and external diameter of colo-rectum in Frizzled feather and Naked neck fowl was 9.7±0.73 cm (L), 8.0±0.52 cm (L) and 2.3±0.22 cm (D), 2.2±0.12 cm (D), respectively. iv

8 Abstract The liver of both the breeds was very soft, dark red to brown in colour consist of right and left lobes. The right lobe was found to be larger and slightly heavier than the left lobe. The gall bladder was situated on the visceral surface of the right lobe. The mean ± SE value of weight of right lobe of liver in Frizzled feather and Naked neck was 18.1±0.29 gm and 19.7±0.52 gm, respectively. The mean ± SE value of weight of left lobe of liver in Frizzled feather and Naked neck was 14.06±0.29 gm and 14.4±0.52 gm, indicated that in both the breeds the right lobe was comparatively heavier than the left lobe. The pancreas was an elongated, pale yellow or brown coloured lobular structure that was found between the descending and ascending duodenal loops. The mean ± SE value of weight of Pancreas of Frizzled feather and Naked neck was 4.4±0.45 gm and 3.6±0.24 gm, respectively. The two bile ducts one from each lobe and two pancreatic ducts opened at the termination of duodenum near the caudal part of gizzard and liver. v

9 Dr. K. M. Panchal Professor and Head, Department of Veterinary Anatomy and Histology, College of Veterinary Sci. & A. H, Anand Agricultural University, Anand CERTIFICATE This is to certify that the thesis entitled GROSS, BIOMETRICAL AND HISTOMORPHOLOGICAL STUDIES ON VARIOUS ORGANS OF THE DIGESTIVE SYSTEM OF FRIZZLED FEATHER AND NAKED NECK FOWLS submitted by MAL TRUPTIBEN BHARATBHAI (Reg. No ) in partial fulfillment of the requirements for the award of the degree of MASTER OF VETERINARY SCIENCE in the subject of VETERINARY ANATOMY AND HISTOLOGY of the Anand Agricultural University is record of bonafide research work carried out by her under my guidance and supervision and the thesis has not previously formed the basis for the award of any degree, diploma or other similar title. Place: Anand Date: / 07 /2016 Dr. K. M. Panchal Major Advisor

10 CERTIFICATE This is to certify that, I have no objection for supplying to any scientist only one copy or any part of this thesis at a time through reprographic process, if necessary, for reference services in a library or documentation centre. Place: Anand Date: / /2016 (MAL TRUPTI B.) (K. M. PANCHAL) Major Advisor

11 Acknowledgement

12 ACKNOWLEDGEMENT I stand with the kernel of my endeavor while pursuing it, many known and unknown hands pushed me forward, and learned soul put me on the right path and enlightened me with the knowledge and experience. I shall even remain indebted to them. I just cannot repay their kind debt they have done on me, but the kind words thanks say a lot. I would like to give my first thanks to Almighty god, as without his mercy, accomplishment of my work & preparation of this manuscript would have not been possible. At this moment, indeed, I consider it to be a privilege to express my deep sense of gratitude and appreciation to my Major Advisor, Dr. K.M. Panchal, Professor and Head, Dept. of Veterinary Anatomy & Histology, College of Veterinary Science & A.H., Anand Agricultural University, Anand for his judicious and constantly inspiring guidance with constructive criticism, persistent encouragement, active persuasion, diligent efforts and caring attitude throughout the course of my study and research work. It was indeed a valuable opportunity for me to pursue my M.V.Sc. study under a potent and brilliant man like him. If at all, an efflorescence element is witnessed in my work the entire credit goes to his blessings. I take this opportunity in expressing my heartfelt thanks to my Minor Advisor Dr. C. J. Dave, Assistant Professor, Department of Veterinary pathology for continuous motivation and indispensable suggestions and counsel during the study and research project. This research work has been tenderly nurtured by all the members of advisory committee. I am extremely grateful to Dr. D.M. Bhayani, Professor, Dept. of Veterinary Anatomy & Histology and Dr. Dr. S.C. Dubal, Professor, Dept. of Veterinary Anatomy & Histology and Dr. Sweta, P. Pandya, Associate Professor, Departmet of Veterinary Anatomy and Histology, Dr. P. V. Parikh, Professor and Head, Dept. of Veterinary Surgery and Radiology for their kind suggestions for their tremendous support, encouraging words, thoughtful criticism, and timely attention during the course of research work. I am also thankful to Dr. Y.L. Vyas, retired Professor and Head, Departmet of Veterinary Anatomy and Histology, for their kind suggestions, constructive criticisms and support during my course and research work. I am extremely thankful to Dr. D.J. Ghodasara, Professor, Dept. of Veterinary Pathology for extending their timely and whole-heartedly co-operation during the course of research work. I also express my sincere thanks to Dr. F. P. Savalia, Research scientist., Poultry research station for providing birds under experimentation of my degree course.

13 I also express my sincere thanks to Dr. A.M. Thaker, Dean, College of Veterinary Science and Animal Husbandry, Anand, for providing me all the necessary facilities during the research work. I would like to express my sincere thanks to Mrs. Himani patel the lab. Technician and Mr. Amitbhai patel, senior cleark in Department of Veterinary Pathology for their cordial corporation during my research work. I have been fortunate enough to avail the corporation of galaxy and constant word of appreciation and encouragement from my respected seniors Dr(s). Harsh Goswami, Aarti Sharma and Shabbir Malik for their kind cooperation during the entire period of study. My group-mates Dr(s). Radha, Jigisha, Dhaval, Alpesh, Aashish,Kirit and Yadav need special mention who always shared my happy and stressful events during the course of this study. They were supportive, forgiving, generous and loving friends without whom I could not have sustained the process of my post-graduation. I feel pleasure in expressing my thanks to my juniers Dr(s). Tanvi, Alka, Vanila and Harish for their love, affection and timely help during my study and research period. If I don t mention the help and caring nature of my on batch mate during the P.G studies then it is not done. Dr. Hetal, god sends a sister in face of her, I miss her my whole life. I would like to extend my cordial thanks to Prakashbhai, Babubhai, Ambalalbhai, and Shanabhai from Department of Veterinary Anatomy and Histology for their sincere support. Indeed, the words are just not sufficient to convey the depth of my feelings and gratitude for the blessings, love, affection and encouragement extended by my beloved Father, mother and sisters. They have always been a perennial source of inspiration for me during endeavor. They truly deserve more than a word of thanks, because without their psychological support, higher study for me would have remained a mere dream. Finally, I would like to thank the Almighty God, under his grace that I live, learn and flourish. Acknowledgement Place: Anand Date: / /2016 (Mal Trupti Bharatbhai)

14 CONTENTS CHAPTER NO. TITLE PAGE NO. I INTRODUCTION 1-3 II REVIEW OF LITERATURE 4-37 III MATERIALS AND METHODS IV RESULTS AND DISCUSSION V SUMMARY AND CONCLUSIONS REFERENCES I-VI APPENDICES I,II

15 APPENDIX-1 LIST OF TABLE Table No. 1 Title Biometrical values (Mean ± SE) of various parameters of digestive organs of Frizzled feather and Naked neck fowls

16 APPENDIX - II LIST OF FIGURES Fig. No Title Gross photograph of Digestive tract of Frizzled feather showing: A-Tongue, B-Cervical esophagus, C-Crop, D-Thoracic esophagus, E-Proventriculus, F-Gizzard, G-Duodenum, H-Pancreas, I-Jejunum, J-Ileum, K-Caeca, L-Colo-rectum, M-Mesentery Gross photograph of Crop of Naked neck fowl showing the longitudinal mucosal folds on the mucosal surface Gross photograph of luminal surface of Proventriculus of Naked neck fowl showing the luminal openings of proventriculur glands Gross photograph of luminal surface of Gizzard in Naked neck showing the thick cutical Gross photograph showing the Pancreatic duct (a) and Bile duct (b) of Naked neck fowl Gross photograph of Liver of Frizzled feather showing the right lobe (Rt.) and left lobe (Lt.) and cardiac notch Gross photograph of Pancreas of Naked neck fowl showing the lobules after removing from duodenal loop Cross section of tongue of Frizzled Feather. H. & E. Staining. 4X. LEp (d) Epithelium of dorsum lingue; LP- Lamina Propria; LEp (v) Epithelium of ventral surface; gl- Lingual salivary gland; eb Entoglossal bone; SM- Submucosa; M- Muscle Cross section of Cervical esophagus of Naked Neck. H. & E. Staining.10X. L-Lumen; LEp Epithelium; LP-Lamina Propria; Lm-Lamina muscularis; gl- gland; Sm- Submucosa; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; Ad- Adventitia Cross section of crop of Frizzled Feather. H. & E. Staining. 10X. LEp Epithelium; LP- Lamina Propria; LM- Lamina muscularis; SM- Submucosa; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; Ad- Adventitia Cross section of Thoracic esophagus of Frizzled Feather. H. & E. Staining. 10X. LEp Epithelium; Tp- Tunica Propria; mm-muscularis mucosae; Sm- Submucosa; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; Ad- Adventitia Cross section of Proventriculus of Naked Neck. H. & E. Staining. 4X. LEp Epithelium; Pg Proventricular gland Lm-Lamina muscularis; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; S- Serosa

17 Cross section of Gizzard of Frizzled Feather. H. & E. Staining 4X. K Keratinized layer; Gg- gizzard gland; SM- Submucosa; M- Musculosa Cross section of Duodenum of Naked Neck. H. & E. Staining. 10X. gc- goblet cell; V- villi; gl- gland; SM- Submucosa; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; S- Serosa Cross section of Jejunum of Frizzled Feather. H. & E. Staining 10X. gc- goblet cell; V- villi; gl- gland; Lm- Lamina muscularis; SM- Submucosa; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular Cross section of Ileum of Frizzled Feather. H&E. Staining 10X.V- villi; gl- gland; Lm- Lamina muscularis; SM- submucosa; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; S- Serosa Cross section of Caecum of Frizzled Feather. H. & E. Staining.10X. gc- goblet cell; V- villi; gl- gland; SM-Submucosa; Lm- Lamina muscularis; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; S- Serosa Cross section of Colo-rectum of Naked Neck. H&E. Staining 10X. V- villi; gl- gland; SM- Submucosa; Lm- Lamina muscularis; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; S- Serosa Section of Liver of Frizzled Feather showing Central vein, Hepatic cells, Kupffer cells and Sinusoid. H. & E. Staining. 40X Section of Pancreas of Frizzled Feather showing PA- Pancreatic Acini and IL- Islets of Lengerhans. H. & E. Staining. 10X.

18 Introduction

19 CHAPTER - I INTRODUCTION Indian poultry industry has transformed from a mere backyard farming into a major commercial farms in just four decades. India is the second largest egg producer and third largest broiler-chicken producer in the world with production estimates of 65,000 million egg (2.8 million tonnes) and 3 million tonnes of broiler meat per year (Cross border Consultancy, 2015). Growth of the poultry sector can contribute to enhance nutrition and poverty reduction in India, because large share of the rural poor people is dependent on poultry for food and income and also because of widespread protein-energy and micronutrient malnutrition (Kumarr, 2012). The total poultry population in the country has increased by 12.39% over the previous census and the total poultry in the country is million in 2012 (GOI, 2012). Frizzled feather is described as a heavy breed, having a single comb. Frizzled feather actually makes good multipurpose chickens with the cockerels reaching a very good weight in 7-8 weeks and hence are reliable layers. Its plumage helps in fast heat dissipation due to which birds are better adapted to the tropical climate especially the humid zones. Frizzled feather fowl does not require vaccination. It is a dual purpose bird suitable for backyard production. The Naked neck is a single comb breed of chicken that is naturally devoid of feathers on its neck and vent. Trivandrum region of Kerala is considered to be the homeland of Naked neck. It is a dual-purpose utility chicken. They are very good foragers and are immune to most diseases. This breed has approximately half the feathers of other chickens, making it resistant to hot weather and easier to pluck. They are preferred in India for their relatively good egg production but mostly for their 1

20 Introduction excellent meat quality. They became strong, resistant to diseases and the costs of keeping them were very low. The birds are capable of tolerating the tropical stress. It lays the largest sized eggs (56.45gm) among all the Indian native breeds of chicken (Kumarr, 2012). Both the Frizzled feather and Naked neck breeds found in costal regions of India (Singh, 2005). The digestive system of any animal is important in converting the food the animal eats into the nutrients its body needs for growth, maintenance, and production (such as egg production). An animal's body breaks down of food occurs through both mechanical and chemical means. In many animals, mechanical action involves chewing; however, because birds do not have teeth, their bodies use other mechanical action. Chemical action includes the release of digestive enzymes and fluids from various parts of the digestive system. After being released from food during digestion, nutrients are absorbed and distributed throughout the animal's body (Jacob, 2015). The floor of mouth accommodates the tongue, which is broad, lacent shaped and having bone inside it. First the food travels down the esophagus and into the crop. The crop is a diverticulum of the esophagus. It is used as a holding tank for food before it can enter the proventriculus. The proventriculus is the glandular stomach which produces acid and adds enzymes which aids in breaking down the food. The gizzard is the muscular stomach caudal to the proventriculus and helps to grind food like seeds. The gizzard is highly keratinized. Food then enters in the intestinal tract. The intestines possess the same anatomical divisions as in mammals, the duodenum, the ileum and the jejunum, though they are not as visibly distinct. Most of the absorption of nutrients occurs in the small intestine. Paired caeca, which are 2

21 Introduction prominent in the chickens and other birds, are notably absent in most pet birds. The large intestine is very short (basically the rectum). In the large intestine, water is reabsorbed, which prevents dehydration. Waste is expelled through the cloaca or vent (Nickel et al., 1977). A Sound knowledge of normal gross, biometrical and histomorphological features, including possible indivisual variations, will greatly assist in recognizing pathology thus providing more accurate diagnosis and will aid in accurate tissue sampling. An understanding of the avian digestive system is essential for developing an effective and economical feeding program for poultry flock and for recognizing when something is wrong and taking necessary actions to correct the problem. Anatomical research on various organs of digestive system of fowl has been reported by several workers in India and abroad, in the literature reviewed. However, there is no report available on various organs of digestive system of Frizzled feather and Naked neck fowls so far in the literature reviewed. Hence, with these views in mind, the research work in gross, biometrical and histomorphological study on various organs of digestive system of Frizzled feather and Naked neck fowls was undertaken which can help the veterinarian while treating the clinical cases of digestive system in a systemic manner with following objectives: 1. To study the gross anatomy of various organs of digestive system. 2. To study the biometry of various parameters of different organs of digestive system. 3. To study the histomorphology of various organs of digestive system. 3

22 Review of Literature

23 3 CHAPTER - II REVIEW OF LITERATURE 2.1 TONGUE Gross Morphology Tadjalli et al. (2008) described gross anatomy of the oropharyngeal cavity in the ostrich (Struthio camelus). They stated that the floor of the ostrich's mouth presents a concave depression between the rami of the lower beak and accommodates the tongue in its caudal third portion. The mucous membrane on the floor of mouth forms a median longitudinal fold which bifurcates caudally and each branch extends toward edge of the tongue. It contains the unpaired broad intraglossal bone which articulates with the basihyoid bone, a blunt round apex, a base and a body. The tongue is supported caudally by the hyoid bone. Igwebuike and Anagor (2013) reported that the tongue of the guinea fowl was a relatively small organ that did not extend to the lateral and rostral margins of the lower beak. A v shaped transverse row of caudally pointed conical papillae demarcated the rostral and caudal parts of the tongue. Whereas the rostral tongue body appeared arrow-shaped and lacked lingual papillae, the lateral margins of the caudal part of the tongue exhibited prominent conical lingual papillae of various sizes. Gupta et al. (2015) studied gross anatomy of oropharyngeal cavity of fowl. It was well demarcated from the pharynx by a transverse row of caudally directed papillae. The tongue was wide and triangular in shape. The dorsal surface was marked by a faded median groove and several transverse grooves. Ventrally the tongue was strongly convex and marked by a median ridge. Jayachitra et al. (2015) studied morphology of oropharyngeal cavity in guinea fowl (Numida meleagris). They mentioned that the tongue was triangular with pointed

24 Review of Literature anterior end and found on the rostral part of the floor of the oropharynx. The most distinguishing structure on the lingual body was a single posterior row of caudally directed lingual papillae which marked the posterior limit of the tongue Biometry Jackowiak and Godynicki (2005) reported that the length of the tongue of the White tailed eagle was 6 cm long. Rossi et al. (2006) reported that the tongue of Partridge was short and its mean length was 1 cm. Jackowiak et al. (2006) mentioned that the length of the tongue of the Cormorant was small 1.4 cm long. Tadjalli et al. (2008) studied that the tongue in ostrich was semicircular, short and quite thick and the length was 1.92 ± 0.15 cm. Gupta et al. (2015) stated that the mean length of the tongue of fowl was 1.94±0.06 cm Histology Igwebuike and Anagor (2013) studied that the dorsal surface of the tongue of the guinea fowl was lined by a nonkeratinized stratified squamous epithelium that exhibited many intraepithelial taste buds. In contrast, the epithelial lining on the ventral surface of the tongue was keratinized stratified squamous epithelium. These epithelial linings on both the dorsal and ventral surfaces of the tongue were a dense irregular connective tissue that formed the lingual submucosa. The lingual submucosa beneath the dorsal surface epithelium showed presence of numerous lingual glands. Each gland was characterized by tubular secretory units, and opened into the dorsal surface of the tongue via a duct. 5

25 Review of Literature 2.2 OESOPHAGUS Gross morphology Getty (1975) observed that the avian esophagus was on the right side of neck (mammal present it was on left side) and it was placed between the pharynx and stomach glandular portion, it was thin and dilatable walls with a diameter relatively larger than of mammals. Mostafa et al. (2012) the oesophagus was a thin walled distensible tube. It lies dorsal to the trachea in the anterior regions of the neck and then runs along the right side. The oesophagus transports the food from the pharynx to the gastric region allowing birds to swallow their food whole. Thus, it contains a number of longitudinal folds which provide distensibility. It was distinguished into three distinct anatomical portions: the cervical part, the crop and the thoracic part. The cervical part of the esophagus was considerably larger than the thoracic part. Shehan (2012) carried out anatomical and histological study of oesophagus in Geese (Anser anser domesticus). The esophagus in goose was an organ located to right side of the neck and composed of two parts; cervical part and thoracic part. Cervical part was longer than thoracic part, and extends from the pharynx to proventiculus. Muhammad et al. (2015) stated that the esophagus in chickens was found to be a long, narrow and straight tube that extends from the glottis at the posterior end of the pharynx, through the neck and thorax to join with the glandular stomach. 6

26 Review of Literature Biometry Rossi et al. (2006) described morphology of oesophagus in the partrigde Rhynchotus rufescens (Tiramidae). They mentioned that the cervical part was long, with approximately cm of length in the female partridge, and cm of length in the male. The thoracic portion was placed below the crop, dorsally to the trachea, and it presents a mean length of 4.50 cm in females and 4.30 cm in males. Hena et al. (2012) the lengths of esophagus were 9.77±0.35cm and 12.46±0.99 cm in the quail and pigeon, respectively. Nasrin et al. (2012) studied gross and histological studies of digestive tract of broilers during postnatal growth and development. They recorded that the average length of oesophagus was 13.75±0.478 cm at Day 28. Shehan (2012) carried out anatomical and histological study of oesophagus in Geese (Anser anser domesticus). The mean and S.D of length in cervical part and thoracic part was recorded cm and cm, respectively. Muhammad et al. (2015) studied the morphometrical parameters of digestive organs in chickens. They noted that the mean length of oesophagus in naked neck and Frizzled feather were ± 0.39 and ± 1.31 cm, respectively. The mean thickness of oesophagus in both the breeds was found to be 0.12 ± 0.02 cm Histology Rossi et al. (2006) reported that the oesophagus mucosa of the partridge was constituted by stratified squamous epithelium and it contains ramified mucous glands and nodular lymphatic tissues. Lymphatic nodules were prominent within the connective tissue (lamina propria). The esophageal glands were mucous type and they were only on the lamina propria. On the lamina propria there were three layers of 7

27 Review of Literature smooth muscle, an inner longitudinal, a medium circular and an outer longitudinal, which was involved in a typical serosa. Mostafa et al. (2012) and Shehan (2012) carried out the histological study in common quail (Coturnix coturnix) and in geese (Anser anser domesticus). They stated that the oesophageal wall consists of usual layers of tubular digestive organs, i.e. mucosa, submucosa, musculosa and adventitia or serosa. The mucosa was formed of stratified squamous epithelium of about seven to eight longitudinal folds of different shapes. These folds are shallow and narrow 7-10 cells thick. The lamina propria was formed of loose connective tissue. Fine connective tissue fibers, fibroblasts and areas of lymphocyte infiltration can be seen in this layer. This layer was considered as an extension of the submucosa. The muscularis mucosa, which was a very well developed continuous layer, was formed of smooth muscle fibers. The submucosa was composed of loose connective tissue with larger blood vessels, lymphatics and nerve fibers. The simple branched mucus glands called oesophageal glands, scattered throughout the submucosa, are present in both the cervical and the thoracic parts of oesophagus. The glands were less developed in the cervical part in comparison to the thoracic part of the organ. An important characteristic feature of the oesophagus in common quail was the presence of mucous glands in the crop. The musculosa of the oesophagus was composed only of smooth muscle and was composed of two distinct layers: an inner circular and an outer longitudinal layer. The circular layer was thicker than the longitudinal layer. The two layers are separated by connective tissue fibers in which runs a nerve plexus. The adventitia was composed of loosely arranged connective tissue which binds the organ to the surrounding tissues. Nerve fibers and 8

28 Review of Literature blood vessels can be found in this layer. The thoracic part of the oesophagus that extends below the diaphragm was covered by a serosa. Nasrin et al. (2012) mentioned that the wall of oesophagus of the chicken was consisted of lamina epithelia, lamina propria, lamina muscularis, submucosa, tunica muscularis and tunica adventitia. The lining epithelium of the esophagus was non keratinized stratified squamous epithelium CROP Gross morphology Rossi et al. (2006) mentioned that in partridge at the entrance of the thorax. The crop was responsible for the storage of food. Partridge crop was located in the clavicle area. Mostafa et al. (2012) reported that in common quail, the crop was located just outside the body cavity in the neck region. It was a storage place for food. From here food passes through the lower oesophagus into the proventriculus and it contains longitudinal folds on the inner surface thus making it distensible Biometry Getty (1975) has described that in fowl, the mean distance between the inlet and outlet of the crop was 3.75 cm in the female. Rossi et al. (2006) studied the morphology of crop in partridge and reported that its length was 3.10 cm in females and 3.35 cm in males. Shehan (2012) carried out anatomical and histological study of oesophagus in geese (Anser anser domesticus). The mean and standard deviation of length of crop was recorded; 7.3 and 1.06 cm. 9

29 Review of Literature Histology Rossi et al. (2006) reported that the histological structure of the crop was similar in several aspects to the structure of the oesophagus. However, the mucous glands were reduced in size and the lymphatic tissues were dispersed in the connective tissue. The mucosa was lined by thin stratum of smooth muscle and other two wider layers of longitudinal and circular musculature. Shehan (2012) studied the histological structure of crop in geese. They found that the histological structure of crop was similar with cervical part except of the mucosa shows thinner than cervical part and constituted with non keratinized stratified squamous epithelium, few mucous glands and nodular lymphatic tissue, the lamina propria with loose connective tissues, collagen and elastic fibrous. The muscular constituted two layers of smooth muscles, an inner circular and an outer longitudinal. The serosa layer composed of loose connective tissue with collagen and elastic fibrous PROVENTRICULUS Gross morphology Hassan and Moussa (2012) studied the microscopic structure of the stomach of domestic duck (Anas platyrhynchos) and domestic pigeon (Columba livia domestica). They mentioned that the proventriculus was cone-shaped in pigeon while it was tubular in duck and arose from the oesophagus. It was related dorsally to left lung, testis or ovary and cranial part of kidney; ventrally, medially and laterally to the left lobe of liver. Also the spleen was located at its medial wall. The demarcation in pigeon was by the appearance of the surface. The surface of oesophags was smooth while that of proventriculus showed densely packed elevations which represent the 10

30 Review of Literature proventricular glands. The line of demarcation in duck is the color (the color of oesophagus was whitish while that of proventriculus was light brown). In addition to the thickness (The wall of proventriculus was thicker than that of the oesophagus). In pigeon, the caudal extent of the proventriculus was marked by a constriction, the isthmus gastric while it was absent in duck. Internally, in duck there was a strong sphincter between esophagus and proventriculus while it was absent in pigeon. Examination of the mucosal surface of the proventriculus revealed the presence of raised papillae, papillae proventricularis, over its entire surface in pigeon having base toward the surface and apex toward the lumen while in duck there were no papillae but only several openings of the ducts of the proventricular glands. Mostafa et al. (2012) noted that in common quail, the proventriculus was a spindle shaped organ located between the oesophagus and the ventriculus. It arises from the oesophagus without a distinct demarcation, the wall was thicker than that of the oeosphagus, and the caudal extent of the proventriculus was marked by a constriction, the isthmus gastris. Das et al. (2013) studied the gross morphology of Kadaknath fowl and reported that the proventriculus was small, elongated, spindle shaped and thick walled tube. The long axis of the proventriculus was slopped from the left to right of the median plane due to the location of other organs like liver, heart and spleen. It slopped from right to the left. The lumen of the proventriculus was narrow at both the ends, which continued anteriorly with oesophagus and posteriorly with gizzard. There was constricted area between the proventriculus and gizzard referred as isthmus. Luminal surface was whitish and showed numerous low rounded papillae which were grossly visible. These papillae were close to each other at the cranial and caudal ends 11

31 Review of Literature whereas, these were free from each other at the middle dilated portion. The outer surface of the proventriculus was glistening and covered with blackish fascia. Dahekar et al. (2014) reported that the proventriculus of Japanese quail formed the first part of stomach and was separated from gizzard by a small constriction known as isthmus or intermediate zone. It completely covered ventrally, medially and laterally by left lobe of liver was located to the left of the median line. Dorsally it was related with left lung. Muhammad et al. (2015) described that the glandular stomach or proventriculus of chicken was relatively small and tubular. It was located caudal to the crop. It was related dorsally to left lung, testis or ovary and cranial part of kidney; ventrally, medially and laterally to the left lobe of liver. Also the spleen was located at its medial wall. The caudal extent of the proventriculus was marked by a constriction, the isthmus gastris. The proventriculus was most prominent and distinct in the Naked neck than the Frizzled feather Biometry Hodges (1974) reported that the proventriculus in adult fowl was approximately 2 cm in length. Lambate and Mamde (2008) reported that the average diameter of proventriculus in 6 weeks old broiler birds was 1.80±00.02 cm. Hena et al. (2012) measured that the mean length of proventriculus in quail and pigeon were 1.75±0.13cm and 1.44±0.28cm respectively; Hassan and Moussa (2012) reported that the mean length of the proventriculus in pigeon was 26 mm while in duck was 60 mm. The diameter of the proventriculus in pigeon was 8 mm while in duck was 15 mm. 12

32 Review of Literature Nasrin et al. (2012) noted that the average length of proventriculus was 3.70±0.122 cm at 28 th day. Dahekar et al. (2014) reported that the average diameter of the proventriculus in Japanese quail at 6th week of age was found to be 3.60±0.57 mm at the oesophageal end, 8.87±0.088 mm at the middle and 4.69±0.114 mm at the gizzard end. Muhammad et al. (2015) recorded that the mean length of proventriculus of Naked neck and Frizzled feather were 3.22 ± 0.24 cm and 3.27 ± 0.22 cm, respectively. The mean widths of the proventriculus of the Naked neck and Frizzled feather were 2.63 ± 0.19 cm and 2.35 ± 0.00 cm, respectively HISTOLOGY Senthamil et al. (2008) carried out histomorphological study on the proventriculus of post-hatch Guinea fowl (Numida meleagris). They described that the proventriculus of the Guinea fowl had all the four tunics viz., tunica mucosa, tunica submucosa, tunica muscularis and tunica serosa. The columnar cells of the superficial epithelium of the tunica mucosa possessed vesicular nucleus in varying position and a clear foamy acidophilic cytoplasm. Mostafa et al. (2012) carried out the histological study in Avian stomach. The proventriculus mucosa, unlike that of the oesophagus, was thrown into folds with varying heights; the folds were lined by a simple columnar epithelium. Lamina propria was occupying the center of the mucosal folds. This layer was dense irregular connective tissue with collagen fibers, fibroblasts and lymphoid infiltration. Delicate smooth muscle fibers were scattered in the deepest part of this layer and between the proventricular glands. That extends to hold two types of gastric glands, the deep and 13

33 Review of Literature the superficial gastric glands. The superficial gastric glands were of simple tubular type appearing in the form of numerous folds of the mucosal epithelium. The walls of these glands were composed of columnar mucus-secreting epithelial cells with centrally located nuclei and a cytoplasm filled with translucent mucous secretion. The submucosa was a narrow connective tissue layer sandwiched between the circular layer of the musculosa and the main mass of the muscularis mucosae. Compound tubulo-alveolar proventricular glands formed the greatest thickness of the proventricular wall. The proventricular glands were distributed throughout the entire organ. The duct system of the proventricular glands was lined with tall columnar epithelium. The proventricular tubules were composed of cuboidal cells. Their nuclei were nearly rounded and located near to the basement membrane. The muscularis mucosa of the proventriculusis formed of two small muscle fibers layers; inner isolated muscular bands arranged in a longitudinal manner and outer band arranged in a circular manner. The deep proventricular glands were located between the inner and the outer layers of the muscularis mucosa. The musculosa was moderately thick and consists of an inner circular and an outer longitudinal muscle layer. The inner layer was two times thick as the outer layer. Serosa was constituted by connective tissue, containing many blood vessels and nerves, lined by mesothelium. Nasrin et al. (2012) reported that the proventriculus of glandular stomach of chicken was consisted of macroscopic papillae with numerous microscopic folds. Single glands grouped to form lobules each of which converged into a common cavity near the surface. The cavities converged to form a common duct that lead to the surface through the apex of a small papilla. The surface epithelium on the folds was a simple columnar tissue, and each fold had a core of lamina propria to support it. The 14

34 Review of Literature wall of glandular stomach was very thick and consisted of several layers i.e. inner mucosal membrane, submucosa, tunica muscularis and outer serosa. The submucosal glands formed the greater part of the thickness of the organ. Dahekar et al. (2014) carried out histomorphological study on Proventriculus of Japanese Quail. They mentioned that the bulk of the wall of proventriculus was made up of proventricular glands in sub-mucosa. The mucosal layer of proventriculus was thrown into various folds of different heights known as plicae. The depressions present between them were sulci and from the bases of sulci short simple tubular glands were extended into lamina propria. The lining epithelium of mucosa was consisted of simple columnar epithelium with no evidence of goblet cells in between them. The height of columnar cells decreased towards the base of plicae. Lamina propria was predominated by large amount of bundles of collagen fibres with few reticular fibres. These connective tissue fibres formed the core of the mucosal folds. The lymphoid follicles were also observed in lamina propria mucosa. The submucosa of proventriculus showed short simple tubular mucosal glands. Lamina muscularis was consisted of longitudinally oriented smooth muscle fibres bundle in an interrupted fashion. These muscle fibres bundles separated tunica mucosa from tunica sub mucosa. The tunica sub-mucosa was consisted mainly of proventriculus glands. The bulk of the wall of the proventriculus was formed by these glands which presented lobules having circular, oval, elongated, triangular or irregular shape. The lobules were separated from the adjacent lobules by means of connective tissue septae. The connective tissue septae were consisted mainly of collagen fibres with few elastic and reticular fibres. The blood vessels were numerous and prominently visible between the lobules. Each lobule was composed of primary, secondary and 15

35 Review of Literature tertiary ducts. The proventricular glands were lined with stratified columnar epithelium with wide lumen. Tunica muscularis was consisted of an inner longitudinal and a thicker outer circular smooth muscle layers. Tunica serosa was typical and composed of thin layer of loose connective tissue. 2.5 GIZZARD Gross morphology Vaish et al. (2007) studied gross and histomorphological studies of gizzard in pre and post hatch Kadaknath fowl. They stated that the gizzard was covered by a glistening layer, was placed between the lobes of the liver. Hena et al. (2012) studied the gross morphology of gizzard in Japanese quail and pigeon. They reported that in both the quail and pigeon, the muscular stomach or gizzard was seen as a spheroidal organ located immediately caudal to the proventriculus and placed partly between the lobes and partly behind the left lobe of the liver. It had a flattened, rounded shape somewhat like a convex lens, with one side slightly larger than the other. Each surface was covered by a glistening layer of tendinous tissue thicker at the centre and becoming thinner towards the edges. Hassan and Moussa (2012) studied the gross morphology of gizzard in Domestic duck and pigeon. They observed that the midgut in both birds was composed of only one region, the ventriculus. The ventriculus in both birds lay in the left caudo-dorsal region of the thoraco-abdominal cavity. It resembles a biconvex lens in shape. It joined the proventriculus by the cardiac sphincter and joined the hind gut by the pyloric sphincter. Ventrally, the liver and the fat laden post hepatic septum obscured the abdominal organs except most of the left surface of the ventriculus. Its 16

36 Review of Literature right surface related to the right lobe of the liver and the descending lobe of duodenum. Mostafa et al. (2012) studied the gross anatomy of gizzard in common quail and stated that the gizzard was a small spheroid organ; lies in the left dorsal and ventral regions of the thoraco-abdominal cavity and placed between the two lobes of the liver. It consists of two pairs of opposing muscles. The caudoventral and craniodorsal thin muscles line the caudal and cranial sac of the ventriculus, respectively. The cranioventral and caudodorsal thick muscles were responsible for the powerful grinding contractions. Muhammad et al. (2015) reported that the muscular stomach of chicken was located immediately after the proventriculus. It was placed partly between the lobes and partly behind the left lobe of the liver. It was oval-shaped. It consisted of a body with two tapering ends, the saccus cranialis and saccus caudalis which were light red in color. The thick muscular wall consisted of the Crassus caudodorsalis and Crassus cranioventralis muscles which were dark redish brown. A much thinner muscle layer, consisting of the tenuis craniodorsalis and caudoventralis muscles was present in the saccus cranialis and the saccus caudalis, respectively Biometry Hassan and Moussa (2012) mentioned that the mean length of the ventriculus in pigeon was 34 mm while in duck was 67 mm. The mean width of the ventriculus in pigeon was 26 mm while in duck was 46 mm. The mean height of the ventriculus in pigeon was 17 mm while in duck was 37 mm. Nasrin et al. (2012) reported that in broiler, the average length of gizzard was 5.32±0.128 cm at 28 th day. 17

37 Review of Literature Muhammad et al. (2015) measured that the mean length of ventricle of Naked neck and Frizzled feather were 5.23 ± 0.35 cm and 5.42 ± 0.20 cm, respectively. The mean thickness of ventricle in Naked neck and Frizzled feather were 1.72 ± 0.13 cm and 1.87 ± 0.09 cm respectively. The mean widths of ventricle of Naked neck and Frizzled feather were 5.12 ± 0.20 cm and 5.08 ± 0.32 cm, respectively Histology Mostafa et al. (2012) noted that the mucous membrane of the gizzard in common quail presents low folds which were lined by columnar epithelial cells possessing generally rounded nuclei. Over the mucous membrane, a thick cuticle was disposed. The lamina propria was constituted by a dense connective tissue and it was occupied by numerous deep simple tubular glands which expand in the base of the fold, partially located between them. Those glands were lined by a simple columnar epithelium, which was lower in the base of the glands and higher in their upper portion in the interior of the glands. There were crypts in the base of the folds. Glandular tubes were narrower, while others were wider. No muscularis mucosa was present making no partitions between the lamina propria and the submucosa. The musculosa was well developed forming the main bulk of the gizzard wall and represented by smooth muscle fibers arranged mostly in a circular manner. The muscular bundles were interspersed with bands of connective tissue. The musculosa was very thick to support the mechanical force of grinding. The serosa, which was constituted by connective tissue lined by mesothelium was rich in blood vessels and nerve endings. It was followed by a subserosal layer. Nasrin et al. (2012) described that in broiler chicken, the gizzard was a highly muscular organ responsible for grinding and macerating the ingesta. Cuticle looked 18

38 Review of Literature like pattern of wavy lines running parallel to the surface. The cuticular layer of the gizzard referred as horny and appeared to consider that it was a keratinous substance. The surface epithelium was simple columnar tissue but branched tubular mucosal glands were simple cuboidal. The lamina propria and submucosa consisted of loose connective tissue. The tunica muscularis were strongly thick and consisted of parallel smooth muscle and outer serosa. 2.6 SMALL INTESTINE Fitzgerald (1969) studied the gross anatomy of small intestine in quails. He observed that the small intestine was consisted of three segments viz; duodenum, jejunum and ileum. However, there was not clear demarcation between the jejunum and ileum. Hodges (1974) studied the gross anatomy of small intestine in fowl. He observed that the small intestine was consisted of three segments viz; duodenum, jejunum and ileum. The jejunum was present in the coils. Ensminger (1992) mentioned the gross anatomy of small intestine in avian and stated that the small intestine was divided anatomically into three sections viz; duodenum, jejunum and ileum. The duodenum was started at the distal end of the gizzard. It was difficult to differentiate the jejunum from ilem in birds. Carnivorous birds had shorter small intestine then herbivorous birds. Mostafa et al. (2012) reported that in common quail, the small intestine extends from the pyloric end of the stomach to the junction of the small intestine, caeca and colon. It was long and consisted of a coiled mass forming a series of loops and lies within the abdominal cavity. It was distinguished into three main parts, the duodenum, jejunum and ileum. The duodenum begins at the end of ventriculus and 19

39 Review of Literature forms an elongated loop about 20 cm long. The jejunum and the ileum were very long and coiled, commence at the caudal end of the duodenum where the bile and the pancreatic ducts were located and terminate at the ileocaecal- colic junction. This junction was where the small intestine, the two caeca and the colon all meet. The external diameter of which was roughly uniform, so the transition between them was anatomically unrecognizable but, they found that Meckel s diverticulum marks the end of the jejunum and the start of the ileum. Meckel s diverticulum appears as a small projection on the outer surface of jejunum, the projection was where the yolk sac was attached during the development of the embryo Gross morphology (a) Duodenum Getty (1975) studied the gross anatomy of small intestine in fowl. The duodenum was light to grayish-red and presents a loop with proximal descending and distal ascending parts. The descending part extended from the cranial part of the right surface of the gizzard caudo-ventrally and mostly on the right side. Caudal to the gizzard, it crossed the left and then bended dorsally to join the ascending part. The ascending part extended cranially and ventrally immediately dorsal to the descending part. It bended dorsally, opposite to the cranial part of the gizzard and crosses the cranial mesenteric artery and joined the jejunum ventral to the right kidney. Pancreatic and bile ducts opened into the ascending duodenum opposite the cranial part of the gizzard. The duodenum held together by a fold of mesentery. Igwebuike and Eze (2010) studied the gross anatomical features in the small intestine of the African pied crow. They stated that the small Intestine was composed of three segments namely; duodenum, jejunum and ileum. The duodenum appeared as 20

40 Review of Literature an U shaped tube with proximal descending and distal ascending part separated by the pancreas. The duodenal loop was located in the caudal part of the abdominal cavity. Two bile ducts and two pancreatic ducts opened very close to each other into the distal end of the ascending duodenum. Hamdi et al. (2013) stated that the small intestine was relatively shorter in the black winged kite. It began immediately after the gizzard and differentiated into duodenum and ileum. The duodenum was relatively long and showed U shaped loop, consisted of descending and ascending limbs. The two limbs of the duodenum were held together by a narrow fold of mesentery. The transition between the jejunum and ileum could not be determined. There was no sharp limit between the duodenum and ileum except for a slight difference in their diameter. Muhammad et al. (2015) noted the gross appearance of the small intestine in chicken and stated that the small intestine was similar in Naked neck and Frizzled feather breeds. It appeared as a thin tube like structure after exposing the abdominal cavity. Duodenum was clearly visible towards the right side of abdominal cavity, whereas jejunum and ileum were partly covered by duodenal loop. The duodenum was in the form of a U shaped loop. The loop consisting of a descending and an ascending limb enclosed pancreas. Ventrally, the duodenum appeared as a bulged part of small intestine. It started from the antero-dorsal aspect of the ventriculus and ended at the terminal point of ascending limb towards the anterior aspect of the abdominal cavity. The duodenum on its left side was related to the right side of ventriculus and dorsally it covered jejunum, caecum and ileum whereas, on the right side it was in contact with the right lobe of liver and lateral body wall. 21

41 Review of Literature (b) Jejunum Getty (1975) studied the gross anatomy of small intestine in fowl. The proximal and distal part of jejunum was nearly straight, while most of the jejunum was arranged in a number of short garland-like coils at the edges of the dorsal mesentery. The loop was close to the right abdominal air sac on the left and near the ovary, ceaca, ileum, ascending duodenum and pancrease on the left and to the liver ventrally. Igwebuike and Eze (2010) studied the gross anatomical features in the small intestine of the African pied crow. They stated that the jejunum was organized in the form of cone shaped spiral coils. The cone shaped jejunum had centripetal coils, a sigmoid flexure and centrifugal coils. The centrifugal coils of the jejunum were embedded within the core of the cone-shaped structure, while the centripetal coils were on the external surface. The sigmoid flexure formed the apex of the cone. Muhammad et al. (2015) described that in chickens, the jejunum arranged in the form of coils (jejunal loops) which were suspended by mesentery towards the dorsal part of abdominal cavity. Ventrally, jejunum was in contact with duodenum and ventriculus. In the small intestine of Naked neck, the sizes of the vitelline (Meckel's) diverticulum and cecal tonsil were most pronounced than in the Frizzled feather. (c) Ileum Getty (1975) studied the gross anatomy of small intestine in fowl. He noted that the ileum was yellowish to reddish gray in color. It was continued with the jejunum up to the middle to the colo-rectum and cloaca and extends cranially dorsal to the ascending duodenum. It was bended dorsally opposite to spleen and caudally near 22

42 Review of Literature the seventh lumbosacral vertebra. Then it continued with colo-rectum caudally, where was there was a small constriction. Igwebuike and Eze (2010) studied the gross anatomical features in the small intestine of the African pied crow. They stated that the the ileum appeared as a short segment that continued from the jejunum to the point of origin of the ceaca. The demarcation between the jejunum and the ileum was marked by the cranial mesenteric artery. Indu et al. (2011) carried out a comparative study on the histomorphology of ileum and in peafowl (Pavo cristatus). They described that the ileum was pale red and extended from the Meckel's diverticulum of jejunum to the ileoceco-colic junction. It was almost straight and began at the midline ventral to the colo-rectum and cloaca and ran in the cranial direction as the long ascending part of ileum. At the level of ovary it bent dorsally and to the left and terminated in the colo-rectum forming the short descending part. The ileum was flanked on both sides by the caeca, to which it was joined by the ileo-caecal ligament. The muscular stomach was seen on the left, jejunum on the right while spleen and ascending duodenum were located ventral to the ileum Biometry Duritis and Mugurevics (2011) studied the biometry of small intestine in ostrich at the age 60 th day. They reported that the average length of duodenum, jejunum and ileum was 52.6, cm and 30.1 cm respectively. Ahmad et al. (2012) studied the biometry of small intestine of Japanese quails. The length of duodenum, jejunum and ileum was 9.38 cm, cm and 6.22 cm, 23

43 Review of Literature respectively at 3 rd week of age, while diameter of the duodenum, jejunum and ileum was 2.84 mm, 2.59 mm and 2.23 mm, respectively at 3 rd week of age. Mandal et al (2012) studied the morphology of small intestine in broiler. They recorded the length of different segments of small intestine at 48 th day. The length of duodenum, jejunum and ileum was cm, cm, 29 cm, respectively. (a) Duodenum Getty (1975) studied the biometry of small intestine in chicken, he found that in adult bird length and diameter of duodenum was cm and cm, respectively. Nasrin et al. (2012) reported that in broiler chicken, the average length of duodenum was 34.13±1.477 cm at 28 th, respectively. Muhammad et al. (2015) reported that the mean length of duodenum in Naked neck and Frizzled feather were ± 1.17 cm and ± 1.45 cm, respectively. The mean thickness of duodenum in Naked neck and Frizzled feather were 0.43± 0.31 cm and 0.10 ± 0.03 cm, respectively. The live body weight of Naked neck ( ± gm) and Frizzled feather ( ± gm). (b) Jejunum Getty (1975) studied the biometry of small intestine in chicken, he found that in adult bird length and diameter of jejunum was cm and cm, respectively. Nasrin et al. (2012) reported that in chicken, the average length of jejunum was ±3.663 cm at 28 th day. Muhammad et al. (2015) measured that the mean length of jejunum of Naked neck and Frizzled feather were ± 1.53 cm and ± 2.93 cm, respectively. 24

44 Review of Literature The mean thickness of jejunum in Naked neck and Frizzled feather were 0.10 ± 0.00 cm and 0.12 ± 0.02 cm, respectively. (c) Ileum Getty (1975) studied the biometry of small intestine in chicken, he found that in adult bird, length and diameter of ileum was cm and cm, respectively. Nasrin et al. (2012) stated that the average length of ileum was 31±3.663 cm at 28 th day. Muhammad et al. (2015) noted the mean lengths of ileum in Naked neck and Frizzled feather were ± 1.64 cm and ± 3.19 cm, respectively. The mean thickness of ileum in Naked neck and Frizzled feather were, 0.12 ± 0.02 cm and 0.10 ±0.00 cm, respectively Histology Bradley and Grahame (1950) studied the histomorphology of small intestine of birds. They observed that the lining epithelium was simple columnar with few goblet cells. The columnar cells have a pronounced striated free border and a basal nucleus. The goblet cells were least numerous towards the summit of the villus. These cells were mounted on basement membrane of argentophil fibers. The paneth cells were strongly granulated cells in the sides and deep part of the crypts of lieberkuhn in the small intestine of birds. The core of the villus was occupied by a lacteal, capillaries, fibroblasts, elastic fibrils, plain muscle bundles, nerves, lymphocytes, plasma cells eosinophils. The lymphoid tissue in the duodenum was abundant. They were usually situated in the corium. The muscularies mucosa was comprised of an outer circular and an inner longitudinal layer of smooth muscle fibers. 25

45 Review of Literature Eurell and Frappier (2007) studied the digestive system of the fowl and stated that the histological structure of the small intestine was similar to that of the mammalian small intestine. The lamina propria and submucosa contained large amounts of diffuse and nodular lymphatic tissue. Musculosa consisted of inner circular and outer longitudinal layers of smooth muscle fibers. The outermost tunic was a typical serosa. Igwebuike and Eze (2010) observed the histology of the small intestine of the African pied crow. They mentioned the wall of small intestine was composed of four layers namely, tunica mucosa, tunica submucosa, tunica muscularies and tunica serosa. The tunica mucosa was modified into many finger-like projections, the villi. Each villus was lined by an epithelium, while its centre contained connective tissue. The villi of the jejunum were numerous, long and wavy, while the villi of the ileum were short. The lamina epithelialis mucosae of all components of the small intestine were simple columnar epithelium with brush border. This epithelium contained many goblet cells especially in the ileum. The lamina propria mucosae consisted of loose connective tissue located just beneath the epithelial layer. The lamina muscularies mucosae was absent and the connective tissue of the lamina propria mucosae was continuous with the tunica submucosa. The tunica submucosa and lamina propria mucosae of the small intestine were laden with many intestinal glands and blood vessels. The tunica muscularis was made up of an inner circularly arranged and an outer longitudinally arranged layer of smooth muscles. Blood vessels and nerve plexuses were present within the muscularis. This tunica serosa was a thin layer of connective tissue whose external surface was lined by mesothelium. 26

46 Review of Literature Ahmad et al. (2012) studied the histomorphology of small intestine in Japanese quail (Coturnix coturnix japonica). They observed that the wall of the small intestine along the entire length contained three tunics viz; tunica mucosa, tunica muscularies and tunica serosa from inner to out. The mucosa of small intestine was thrown in to finger like projections known as villi, which were finger shaped in duodenum, tongue shaped in jejunum and spatula shaped in ileum. Lamina propria formed the bulk of villus and contained connective tissue fibers and cells Tunica serosa was predominantly composed of collagen fibers. Mostafa et al. (2012) reported that the small intestine in common quail was conveniently divided into three main regions namely, the duodenum, the jejunum and the ileum. All the three divisions show the usual tunicae namely; mucosa, submucosa, musculosa and serosa. The mucosa of the intestine was thrown into villi which show a marked variation in density, shape and size in the different regions of the intestine. Intestinal villi gradually decrease in length and size moving from the duodenum to the ileum. The mucosa was built up of a lamina propria of loose connective tissue supporting the mucosal membrane which was thrown into deep, narrow fingerlike villi in the duodenum while the villi were relatively short, somewhat broad and numerous in the ileum. The mucosa consists of a simple columnar epithelium and a tunica propria. The muscularis mucosa was represented by a narrow part of longitudinally arranged smooth muscle fibers towards the side of the submucosa, but on the side of the lamina propria, it was represented by vertically arranged smooth muscle fiber strands. The columnar cells possess elongated nuclei and a clear cytoplasm. Goblet cells frequently occur amongst the columnar or absorptive cells. Each cell was rounded or oval in shape. The goblet cells were more numerous in the 27

47 Review of Literature ileum than in the duodenum. The goblet cells increase from the duodenum towards the rectum. Lymphocytes were scattered amongst the bases of the columnar epithelial cells. They were small more or less spherical and their nuclei were rounded and darkly stained. Crypts of Lieberkühn, in the form of simple tubular stands, occur at the bases of the villi, being more numerous and too crowded in the duodenum. They were built of cells similar in structure to those of the mucosal epithelium. The cores of the villi were formed of the areolar connective tissue of the tunica propria. The submucosa was thin, narrow and hardly distinguished in some regions. The submucosa connective tissue holds few blood vessels. The muscularis mucosa is composed of thin layer of longitudinal muscle fibers which merges gradually into the submucosa and extends into the core of the villi. The musculosa consists of two smooth muscle layers; outer longitudinal layer and a thick circular muscle layer. All muscle fibres were of the unstriated type. Two muscle layers surround the intestine, the inner circular and outer longitudinal layers that allow mixing and propulsion of the digesta through the intestinal tract. The serosa is made up of flattened simple squamous epithelium. Hamdi et al. (2013) studied histomorphology of small intestine in Elanus caerulus (Avian). The small intestine was differentiated into three compartment namely; duodenum, jejunum and ileum. It showed the usual tunics namely; mucosa, submucosa, musculosa and serosa. The mucosa was thrown into simple longitudinal villi. The submucosa was formed of thin loose connective tissue, which was contained number of blood vessels. The muscularis mucosa was represented by a narrow part of longitudinally arranged smooth muscle fibers towards the side of the submucosa, but on the side of the lamina propria, it was represented by vertically arranged smooth 28

48 Review of Literature muscle fiber strands. The mucosa was invaginated at the bases of the villi into straight tubular glands (crypts of Liberkuhn), which were continued with the columnar epithelium lining the villi. The lamina propria extended between the crypts of Liberkuhn and formed the underlying layer of the epithelial cells of the villi. The musculosa consisted of two layers of smooth muscle fibers, outer longitudinal and inner circular muscle layers. The serosa was the outermost layer made up of flattened simple squamous epithelium with flattened nuclei. Levi et al. (2013) studied the histomorphology of the small intestine of Anak and Marshal Broiler. The villi of small intestine were lined by simple columnar epithelium with basally located nucleus. Lamina propria showed single line of glands. Inner circular and outer longitudinal muscle layers contained smooth muscle fibers. 2.7 LARGE INTESTINE Gross Morphology (a) Caecum Mostafa et al. (2012) noted that the right and left caeca in common quail arise from the lateral walls of the colo-rectum, close to the junction with ileum, they were well developed. Each caecum could be divided externally into a short proximal neck, a long middle thin-walled body, and a short apex. Nasrin et al. (2012) observed in chickens that the large intestine started from the caeca, and the two caeca were blind pouches and extend along the line of the small intestine towards the liver having proximal and distal part, and were closely attached to the small intestine along their length by the mesentery. Each caecum had three main parts proximal end, middle part and distal end and was long cylindrical expansions. 29

49 Review of Literature Muhammad et al. (2015) reported that in chicken, the two ceca were blind pouches and extend along the line of the small intestine towards the liver having proximal and distal part, and were closely attached to the small intestine along their length by the mesentery. Each caecum had three main parts with the caecal tonsils at the initial portion. (b) Colo-rectum Indu et al. (2011) described in the pea fowl that the colo-rectum was short and light grey in colour which ran in nearly a straight line below the vertebrae and opened into the ileum cranially and cloaca caudally. Nasrin et al. (2012) studied the colorectum in chicken and stated that colorectum was the terminal part of the intestine, passing between the ileo-cecal junction and the cloaca. It was comparatively short and straight and had thick, muscular walls. Gosomji et al. (2015) in the guinea fowl described that the colorectum was appeared as a short and straight tube extending from the distal part of the ileum and it opens distally into the the cloaca. Muhammad et al. (2015) stated that in chicken, the colorectum was the terminal part of the intestine, passing between the ileo-cecal junction and the cloaca. It was comparatively short and straight Biometry (a) Caecum Hena et al. (2012) mentioned that in the quail the right and left cecal lengths were recorded as 8.13±0.26cm and 8.13±0.26cm, respectively. 30

50 Review of Literature Nasrin et al. (2012) reported that in chicken, the average length of each caeca was ±1.732 cm at 28 th day. Muhammad et al. (2015) reported that the mean lengths of caecum of Naked neck and Frizzled feather were ± 0.57 cm and ± 0.91 cm, respectively. The mean thickness of the caecum of Naked neck and Frizzled feather were 0.12 ± 0.02 cm and 0.12 ± 0.02 cm, respectively. (b) Colo-rectum Nasrin et al. (2012) noted that the average length of colorecti was 8.83±0.037 cm at 28 th day. Muhammad et al. (2015) reported that the mean lengths of colorectum of Naked neck and Frizzled feather were 6.85 ± 0.34 cm and 7.13 ± 0.67 cm, respectively. The mean thickness of colorectum in Naked neck and Frizzled feather were 0.12 ± 0.02 cm and 0.15 ± 0.02 cm, respectively Histology (a) Caecum Mostafa et al. (2012) in common quail described that each caecum was distinguished into three main regions: proximal, middle and distal. Its mucous membrane was raised into simple villi. These show a gradual change in their depth and width from end to end. Thus, the height of the villi increased as the villi neared the proximal caecum. Conversely, the villi height decreased as the position moved far from the proximal caecum. The villi were lined by a simple columnar epithelium whose cells resemble those of the small intestine. Villi were found and had globet cells and crypts, and the muscle layer was thicker. No villi in the middle zone caecum were found. The muscularis mucosa was composed of thin layer of longitudinal 31

51 Review of Literature muscle fibers. Accordingly, the narrow and thin submucosa connective tissue layer merges into that at the lamina propria. The musculosa consists of two layers of unstriated muscle fibres: an outer longitudinal layer and inner circular. The caecum was covered externally with a thin serosal layer; formed of simple squamous epithelial cells which possess flattened nuclei. (b) Colo-rectum Indu et al. (2011) carried out the histomorphology of colo-rectum in peafowl (Pavo cristatus). In the colo-rectum the villi were longer. The mucosa was folded extensively to increase the absorptive area. The crypts of Lieberkuhn were considerably reduced in depth and opened not only around the villi, but also on the flat areas between them. The lamina propria was infiltrated with lymphoid cells. The epithelium was similar to that seen in ileum but the chief cells were obscured by the relatively larger number of distended mucous cells. The goblet cells were so numerous that they were even found to be among the glandular cells of the crypts of Lieberkuhn. The muscularis mucosa was thick and extended into the corium of the villus. In the tunica muscularis, the inner circular layer was thinner. The outer longitudinal layer made up of smooth muscle fibers. Well developed tunica muscularis might facilitate the movement of the extensively folded mucosa. The mucous cells were more in colorectum to facilitate the passage of the contents of large intestine. Mostafa et al. (2012) in common quail described that the wall of the rectum was made up of serosa, musculosa, submucosa, muscularis mucosa and mucosa. The serosa was a thin layer composed of simple squamous epithelium with flattened nuclei. The musculosa was made up of two muscle layers; an outer thin longitudinal 32

52 Review of Literature and thick circular one. The submucosa consists of loose connective tissue holding blood vessels. The muscularis mucosa was composed of longitudinal muscle fibers. This layer extends inside the mucosal folds as vertical muscle fiber strands. The mucosa was thrown up into numerous leaf-like villi, all covered by simple columnar epithelium containing goblet cells. The goblet cells were numerous in number and open into the lumen. At the base of the mucosal folds, rectal glands (simple tubular) are noticed. These glands were crypts as in the small intestine, lined with simple columnar epithelium and goblet cells. 2.8 LIVER Gross morphology Clark (2005) described that the liver in birds was one of the largest, most important organ in the body. The avian liver was suspended by peritoneum that was connected with overlying air sac and surrounded by hepatic celomic cavities. The avian liver has two lobes, most avian have the right lobe larger than the left one. However, the left lobe of the domestic fowl divided into the dorsal and ventral parts. Mostafa et al. (2012) studied the gross anatomy, histology and histochemistry of the alimentary canal of common quail (Coturnix coturnix). The liver of common quail was dark red brown in colour, Placed in its natural position. It consists of two lobes, namely; the right and the left lobes, the former was much larger than the left one and the latter was sub divided into two lobes. The right and the left lobes were united together antero-dorsally by a thin isthmus. It was connected to both the diaphragm and the ventral body wall by means of the falciform ligament. The gall bladder was partially embedded in the right lobe of the liver at the posterior surface. It was somewhat elongated and oval-shaped thin walled sac, dark green in colour. Two 33

53 Review of Literature bile ducts emerge from the right lobe. One of these originates from the gall bladder and the second provides a direct connection from the liver to the small intestine. Ahmed (2015) described anatomical and histological characteristics in liver of male indigenous Turkey (Meleagris gallopava). He observed that the liver of the male turkey located in the right and left hepatoperitoneal cavity. It had red- brown to dark brown color. The liver of male turkey consisted of right and left lobes, left lobe subdivided into dorsal part and ventral part while right lobe undivided. Javaid et al. (2014) carried out gross anatomical and histological studies on the liver of Broiler. They noted that anatomically, bird liver was divided into right and left lobes which were joined cranially at the midline. The right lobe was larger and the left lobe was subdivided into the dorsal and ventral parts. Moslem (2015) studied that the the liver was the largest gland in the poultry body. The poultry liver consists of two lobes: right lobe and left lobe, right lobe undivided and was the larger than left lobe but the left lobe was divided into two parts. Right lobe of the liver in the chicken had a gallbladder but left lobe had no gallbladder Biometry Ahmed (2015) measured that the weight of the liver of male turkey was 1.89 ± % in relation with the body weight. Javaid et al. (2014) recorded the minimum and maximum weight of fresh liver of broiler from 6th week of age was gm. The mean and standard deviation of weight of fresh liver of broiler from 6th week of age was ±5.93 gm. 34

54 Review of Literature Histology Sivagnanam et al. (2004) carried out histological studies of liver in Guinea fowl. The liver of the Guinea fowl was a compound tubular gland. The Glisson s capsule was thin. The capsule was made up of dense connective tissue consisting of collagen, reticular and a few fibers. The hepatic lobules were centered on the central vein with the portal canals at the periphery. Shape of the hepatocytes varied from cuboidal to polygonal. The cytoplasm of the hepatocytes was granular and acidophilic as in fowl. The sinusoids were lined by flattened endothelial and Kupffer cells were present. Ahmed (2015) described the anatomical and histological characteristics in liver of male indigenous turkey (Meleagris gallopava). The histological results were declared there was no clear distinct limited between lobules in the hepatic parenchyma of turkey's liver, due to paucity or absence of the interlobular connective septa, except in the portal area. Each lobule has central vein. The histology picture of the liver in turkey was composed of plates of hepatocytes which are usually arranged as two cell thickness between the liver sinusoids, these are hepatic cords, these cells ordered radially around the central vein. The hepatocytes were polyhedral in shape and it had cytoplasm contain many granules with their ovoid nucleus which had distinct nucleolus. The sinusoids lined by endothelial cells that were nearly flattened in shape with presence of the Kupffer s cells contract with endothelial cells, last cells had large nucleus with some debris in cytoplasm, the sinusoids continued with the hepatic vein and portal vessels. The portal area contained the interlobular connective septa which composed the branches of the portal vein, branch of hepatic artery and usually bile ducts. The bile duct lined by simple cuboidal epithelium, while the 35

55 Review of Literature hepatic artery lined by endothelial cells of the simple squamous epithelium protruded into the lumen containing RBCs and a layer of smooth muscle fiber more that of the branch of the portal vein which was lined by endothelial cells, protruded into the large lumen. Moslem (2015) described the internal organization of the liver of poultry. Hepatic parenchyma was combined of clusters and cords or tubules of polyhedral cells separated by a sinusoidal grate. Hepatocytes had spherical, euchromatic nuclei with one or more nucleus. The Vonkupffer cells located between the endothelial cells of the sinusoids between the hepatic cords with acidophilic cytoplasm and large basophilic nucleus. Kupffer cells were macrophages that are attached to the luminal surface or inserted in the endothelial lining of hepatic sinusoids. In this site, Kupffer cells play a key role in host defense by removing foreign, toxic and infective substances from the portal blood and by releasing beneficial mediators. Kupffer cells, morphologically different from the endothelial cells, bulged strongly into the sinusoidal lumen. They were fixed to the endothelial lining by small junctional areas which occurred between the Kupffer cell body and the "cytoplasmic processes" of the endothelium. The portal triad were consisted of hepatic artery, portal vein, bile duct also lymph vessels. Both of the hepatic vein and hepatic artery increase through the liver in opposite directions to each other between the centre and periphery of the organ. 2.9 PANCREAS Gross morphology Getty (1975) has described that the pancreas of fowl is pale yellow or reddish in colour and has dorsal, ventral and splenic main lobes, part of the ventral lobe 36

56 Review of Literature sometimes being referred to as the third main lobes. The dorsal, ventral and third lobes are long and thin and extend longitudinally in the dorsal mesentery joining the ascending and descending parts of the duodenum. The splenic lobe is small. Its cranial part lies close to the spleen; caudally its joins the dorsal lobe. The gland has three main excretory ducts. The splenic lobe has no separate excretory duct. The pancreatic and bile ducts open into the ascending part of the duodenum opposite the cranial part of the muscular stomach. Mostafa et al. (2012) observed that the quail pancreas was a pale-yellow organ with a finely lobulated surface located between the ascending and descending loops of the duodenum. It was composed of the dorsal, ventral, third and splenic lobes united together by a broad median bridge. Three pancreatic ducts opening into the duodenum proceed directly from the dorsal, ventral and third lobes, respectively. Deprem et al. (2015) studied that the goose pancreas was found between the ascending and descending duodenal loops and was composed of dorsal, ventral, third, and splenic lobes. The two main pancreatic ducts; dorsal and ventral, which transmit pancreatic secretion into the duodenum Histology Bacha and Bacha (2000) noted that the Pancreas of the chicken resembles that of the mammal. The exocrine portion is tubuloacinar. Lobulation is indistinct because of the lack of interlobular connective tissue. Islets of Lengerhans are abundant. Two types of islets, alpha and beta, can be easily recognized. Columnar alpha cells characterize the alpha islet. Polygonal beta cells are the principal cells of the beta islets. Alpha islets produce glucagon, whereas beta islets from insulin. 37

57 Materials and Methods

58 CHAPTER - III MATERIALS & METHODS The present work was carried out on Gross, Biometrical and Histomorphological Studies on Various Organs of the Digestive System of Frizzled feather and Naked neck Fowls (Gallus gallus domesticus) at the Department of Veterinary Anatomy and Histology, AAU, Anand. For the present study, 12 healthy adult birds include 6 each of Frizzled feather and Naked neck fowls (aging at 14 th weeks) were procured from the Central Poultry Research Station, AAU, Anand to the Department of Anatomy and Histology, AAU, Anand. 3.1 GROSS STUDY After the procurement of the birds, the whole body weight of the birds was measured on the digital weighing machine. Before the evisceration of the digestive tract, the fowls were sacrified by the Halal method (Wilson, 2005). The observations and photography of the digestive tract for its in situ condition were carried out. After evisceration of the digestive tract, the following organs were studied for their biometry. 1. Tongue 2. Esophagus 3. Crop 4. Proventriculus 5. Gizzard 6. Duodenum 7. Jejunum 8. Ileum

59 Materials & Methods 9. Caecum 10. Colo-rectum 11. Liver 12. Pancreas The biometry of all above viscera which include mainly gross measurements like length and diameter of the tubular organs was carried out after collection. 3.2 BIOMETRY OF DIGESTIVE ORGANS Length of the tongue: The length of the tongue was taken by measuring the distance from apex/tip to the end of caudally directed lingual papillae. Length of the cervical part of oesophagus: Length of the cervical part of eesophagus was measured from the glottis to where it joins the crop. External diameter of the cervical part of esophagus: External diameter of the cervical part of esophagus was measured with the help of non-stretchable thread at three different regions and was averaged out for the record. Length of the thoracic part of esophagus: Length of the thoracic part of esophagus was measured from origin at the crop to where it joins the proventriculus. External diameter of the thoracic part of esophagus: External diameter of the thoracic part esophagus was measured with the help of non-stretchable thread at three different regions and was averaged out for the record. The length of the proventriculus: The length of the proventriculus was measured from the caudal end of esophagus to where it joins with gizzard at isthmus. External diameter of the proventriculus: External diameter of the proventriculus was measured at three different levels viz; at the origin, at the middle and at the terminal part with the help of non-stretchable thread. 39

60 Materials & Methods The Length, width and periphery of the gizzard: The Length, width and periphery of the gizzard was measured at greater curvature with the help of non-stretchable thread. The length of the duodenum: The length of duodenum was measured from gizzard outlet to the origin of pancreatic duct. External diameter of the duodenum: External diameter of the duodenum was measured at the origin, at the middle and at the termination part near jejunum with the help of non-stretchable thread. The length of the jejunum: The length of the jejunum was measured from origin of pancreatic duct to the Meckel's diverticulum. External diameter of the jejunum: External diameter of the jejunum was measured with the help of non-stretchable thread. The length of the ileum: The length of ileum was measured from vitelline diverticulum to ileo-ceco-colic junction (Hassan and Moussa, 2012; Giannenas et al., 2010). External diameter of the ileum: External diameter of the ileum was measured with the help of non-stretchable thread. The length of the caecum: The length of the caecum was taken by measuring the distance from the ileo-ceco-colic junction to blind end of caeca. External diameter of the caecum: External diameter of the caecum was measured with the help of non-stretchable thread at different levels origin, middle and at blind end. The values were averaged out. The length of the colo-rectum: The length of the colo-rectum was taken by measuring the distance from the ileo-ceco-colic junction up to the coprodeal orifice. 40

61 Materials & Methods External diameter of the colo-rectum: External diameter of the colo-rectum was measured with the help of non-stretchable thread. Weight of liver (Rt. & Lt. lobe) and pancreas: Weight of liver (Rt. & Lt. lobe) and Pancreas were measured with the help of digital weighing machine. Data Analysis The biometrical data obtained were expressed as Mean ± SEM (Standard Error of Mean) and subjected to statistical analysis using Statistical Package for the Social Sciences (SPSS) version One-Way Analysis Of Variance (ANOVA) was used to determine the level of significant difference in mean values among both the breeds. Preservation of samples After taking the all biometrical parameters the small pieces of samples (~0.5cm 3 ) were preserved in 10% formalin solution for paraffin block making method to study their microstructures after staining (Drury and Wallington, 1980). 3.3 HISTOMORPHOLOGICAL STUDY For histomorphological study, the sections were processed for making the paraffin block. The paraffin blocks were sectioned at 6 μm thickness using sliding microtome machine and were processed for routine staining technique such as Haematoxylin and Eosin stain (Singh and Sulochana, 1996). The microphotography of various structures was carried out for keeping the records for further study. 41

62 Results and Discussion

63 CHAPTER - IV RESULT S & DISCUSSION The present work entitled Gross, Biometrical and Histomorphological Studies on Various Organs of the Digestive system of Frizzled feather and Naked neck Fowls (Gallus gallus domesticus) was carried out at the Department of Veterinary Anatomy & Histology, College of Veterinary Science & A. H., Anand Agricultural University, Anand, Gujarat. The observations and the results of various measurements on different organs of the digestive system include tongue, oesophagus, crop, proventriculus, gizzard, small intestine viz., duodenum, jejunum and ileum and large intestine viz., right and left caeca and colorectum, liver and pancreas of adult Naked neck and Frizzled feather fowls. The gross as well as microscopic findings of various organs studied in both the breeds were almost similar. Hence, there is no separate description regarding these studies has been made. However, there was a statistically non-significant difference found in the biometrical values of the digestive organs recorded and presented here. The results of the present study have been discussed under different headings as follows: 4.1 Gross morphology of the tongue The tongue of the Frizzled feather and Naked neck fowl was brownish in color and triangular in shape. It has pointed apex and a wide base and short body. The body has dorsal and ventral surfaces. The mucosa of ventral surface was comparatively thinner and smooth. The tongue was attached ventrally with the floor of lower beak. The dorsal surface was marked by a fade median groove. At the root on the dorsal surface there was a single row of caudally directed papillae. The tongue of both the breeds was supported by the visceral bone, entoglossal process of hyoid bone (Fig.1A). 42

64 Results & Discussion The present observations are similar on the tongue morphology recorded earliar by Tadjalli et al. (2008) in ostrich, Igwebuike and Anagor (2013) in Guinea fowl, Gupta et al. (2015) in fowl, Jayachitra et al. (2015) in Guinea fowl Biometry of the tongue Length of Tongue The mean ± SE value of length of the tongue of Frizzled feather and Naked neck was 2.40±0.68 cm and 2.15± 0.09 cm, respectively. There was no significant difference (P>0.05) between the length of the tongue of both the breeds. The present observations on length of tongue are higher than the observations of those reported by Rossi et al. (2006) in Partridge (1 cm), Jackowiak et al.,(2006) in Cormorant (1.4 cm), Tadjalli et al. (2008) in ostrich (1.92±0.15 cm) and Gupta et al. (2015) in fowl (1.94±0.06cm). This variation in the length of tongue may be due to the difference in the species and the body size of the birds Histology of the tongue The mucosal epithelium of tongue was observed to be composed of keratinized stratified squamous epithelium which was thick on the dorsum linguae. The ventral surface of the tongue was smooth. The epithelial mucosa on dorsal surface of tongue was about three times thicker than that of the ventral surface of tongue in both the breeds. The tunica propria comprised the second layer, which contained the anterior lingual salivary glands on either side. It was made up of fibrous tissue containing blood vessels, lymph vessels and nerves. The entoglossal process of hyoid bone was present in the middle part with skeletal muscles comprised the muscle mass of the tongue that appeared to be poorer in size and development than that of mammalian tongue (Fig. 8). 43

65 Results & Discussion Similar observations were reported earlier by Igwebuike and Anagor (2013) in Guinea fowl. The present study showed that the histological structure of tongue is similar in both the breeds. 4.2 Gross morphology of the esophagus The esophagus in both the breeds was found to be a long, narrow and straight tube extended from the pharynx to proventriculus. It lies dorsal to the trachea in the anterior regions of the neck and then runs along the right side. It was composed of two parts; cervical part and thoracic part separated by its own diverticulum called crop. Cervical part was longer than thoracic part (fig.1b). These observations are in accordance with the observations of Getty (1975) in fowl, Mostafa et al. (2012) in common quail, Shehan (2012) in Geese and Muhammad et al. (2015) in chicken Biometry of the esophagus Length and External diameter of cervical part and thoracic part of esophagus. The mean ± SE value of length of cervical part and thoracic part of esophagus of Frizzled feather and Naked neck was 10.7± 0.57 cm, 8.16± 0.44 cm (cervical part) and 6.50±0.36 cm, 6.78±0.22 cm (thoracic part). The mean ± SE value of total length of esophagus of Frizzled feather and Naked neck was ± 0.73 cm and ± 0.56 cm. The external diameter was 2.10 ± 0.15 cm and 1.91±0.18 cm (cervical part), 1.91±0.13 cm and 1.75 ± 0.11 cm (thoracic part), respectively. There was a significant difference (P<0.05) between the length of cervical part esophagus whereas, non significant difference (P>0.05) between the length of thoracic part esophagus of Frizzled feather and Naked neck. There was no significant difference (P>0.05) 44

66 Results & Discussion between the external diameter of cervical part and thoracic part of esophagus in both breeds. The present values are comparatively lesser than the observations reported by Muhammad et al. (2015) recorded in Naked neck and Frizzled feather i.e ± 0.39 cm and ± 1.31 cm, respectively. The result was lesser than observations of Rossi et al. (2006) in partridge, the cervical part (11.72 cm), and higher than thoracic part (4.50 cm) and Hena et al. (2012) in quail (9.77±0.35 cm) and in pigeon (12.46±0.99 cm), Nasrin et al. (2012) in chicken (13.75±0.478 cm) at 28 day. It might be due to the breed difference Histology of the esophagus The mucosa of esophagus was formed of stratified squamous epithelium with about seven to eight longitudinal mucosal folds of different shapes like pointed, rounded, curved etc. The lamina propria was formed of loose connective tissue components. The muscularis mucosa was very well developed in the form of a continuous layer that was formed of smooth muscle fibers. The submucosa was composed of loose connective tissue with larger blood vessels, lymphatics and nerve fibers. The submucus glands or esophageal glands were present in both, the cervical and the thoracic parts of oesophagus. The musculosa was composed of smooth muscles and was arranged in two distinct layers: an inner circular and an outer longitudinal layer. The circular layer was thicker than the longitudinal layers. The outer fibrosa in cervical part and the serosa in thoracic part comprised the external tunic (Fig. 9, 11). The present observations of esophagus in Frizzled feather and Naked neck are in agreement with the observations of Rossi et al. (2006) in partridge, Mostafa et al. (2012) in common quail, Shehan (2012) in geese and Nasrin et al. (2012) in chicken. 45

67 Results & Discussion 4.3 Gross morphology of the crop The crop was situated at right ventro-lateral aspect to the cervical esophagus in front of thoracic inlet in both the breeds of fowl (Fig. 1C). It was a storage place for food and contains longitudinal mucosal folds on the mucosal surface (Fig. 2). In the present study, The crop was present which are in agreement with those described by Rossi et al. (2006) in partridge, Mostafa et al. (2012) in common quail Biometry of the crop The mean ± SE value of distance between the inlet and outlet of the crop in Frizzled feather and Naked neck fowl was 4.90 ± 0.37 cm and 4.80 ± 0.24 cm, respectively. There was no significant difference (P>0.05) among the distance between the inlet and outlet of the crop of both the breeds. The present observations are slightly higher than those reported earlier by Getty (1975) in fowl (3.75) cm, Rossi et al. (2006) in females (3.10 cm) and in male (3.35 cm) partridge and lower than Shehan (2012) in geese (7.3 cm). It might be due to the breed difference Histology of the crop The mucosa was thicker than pre-crop oesophagus and constituted with non keratinized stratified squamous epithelium. The lamina propria was formed of loose connective tissue, collagen and elastic fibrous. The mucous glands were found to be absent. The musculosa constituted two layers of smooth muscles, an inner circular and an outer longitudinal. The serosa layer composed of loose connective tissue with collagen and elastic fibres (Fig. 10). 46

68 Results & Discussion In the present study, the mucous glands were found to be absent in the crop of both the breeds. However, in contrary with the observations reported by Rossi et al. (2006) in partridge and Shehan (2012) in geese, Mostafa et al. (2012) in common quail in which the mucous gland was present. Remaining histological structure was similar to the reports of Rossi et al. (2006) in partridge and Shehan (2012) in geese, Mostafa et al. (2012) in common quail. 4.4 Gross morphology of the proventriculus The proventriculus in Frizzled feather and Naked neck fowl was small, elongated, spindle shaped and thick walled tube, located in the front part of body cavity separated in front by the esophagus and the gizzard (Fig. 1E) covered by visceral surface of two lobes of liver. It was related dorsally to lung and cranial lobes of kidney; ventrally, medially and laterally to the left lobe of liver. Also the spleen was located at its right wall near the gizzard. There was constricted area between the proventriculus and gizzard called isthmus. Luminal surface was whitish and showed numerous low rounded papillae indicated the luminal openings of proventriculur glands, which were grossly visible (Fig.3). The outer surface of the proventriculus was glistening and covered with serous layer. Similar findings on anatomical location and gross structure of proventriculus were recorded earlier by Mostafa et al. (2012) in common quail, Das et al. (2013) in fowl, Dahekar et al (2014) in Japanese quail and Muhammad et al. (2015) in chicken. However, Hassan and Moussa (2012) stated that the proventriculus was cone-shaped in pigeon while it was tubular in duck. 47

69 Results & Discussion Biometry of the proventriculus The mean ± SE value of length of proventriculus of Frizzled feather and Naked neck fowl was 4.15±0.14 cm and 3.83±0.10 cm, respectively. The mean ± SE value of external diameter of proventriculus at cranial, at middle and at caudal part in Frizzled feather was 3.51±0.20 cm, 5.25± 0.17 cm and 3.80±0.21 cm, respectively. While in Naked neck it was 3.26 ± 0.35 cm, 4.50 ± 0.36 cm and 3.53±0.33 cm, respectively. There was no significant difference (P>0.05) between length and external diameter of proventriculus at cranial, at middle and at caudal parts in both the breeds under study. These present observations on length of the proventriculus of both the breeds are in accordance with the previous observations of Nasrin et al. (2012) in chicken (3.70±0.122) and Muhammad et al. (2015) in Frizzled feather (3.27 ± 0.22 cm) and Naked neck (3.22 ± 0.24 cm). But the present observation found to be higher than those reported by Hodges (1974) in adult fowl (2 cm), Hena et al. (2012) in quail (1.75±0.13 cm) and pigeon (1.44±0.28 cm). Hassan and Moussa (2012) recorded in pigeon (2.6 cm) and in duck (6.0 cm). These present observations on external diameter of proventriculus of both the breeds are in accordance with the previous observations of Muhammad et al. (2015) in Frizzled feather (2.35 ± 0.00 cm) and Naked neck (2.63 ± 0.19 cm). But the present observations on external diameter of proventriculus are found to be higher than those reported by Lambate and Mamde (2008) in broiler bird (1.80±00.02 cm). Hassan and Moussa (2012) reported that the diameter of the proventriculus in pigeon was (8 mm) while in duck was (15 mm) and Dahekar et al. (2014) in Japanese quail at 6th week of age also found that the average diameter of the proventriculus at the oesophageal end 48

70 Results & Discussion (3.60±0.57 mm), at the middle (8.87±0.088 mm) and at the gizzard end (4.69±0.114 mm) which were comparatively more than present observations of both the birds Histology of the proventriculus The mucosa of proventriculus was having tall gastric ridges. It was lined by simple columnar epithelium. Lamina propria was having the superficial mucosal glands. Submucosa was full of large submucosal glands. The lumen of submucosal glands was lined by tall columnar epithelium. The secretary epithelium of submucosal glands was simple cuboidal. The musculosa was made up of inner circular and outer longitudinally arranged smooth muscle fibres. The tunica externa was made up of a serosa (Fig. 12). Similar findings were observed on general histological structure of proventriculus by Senthamil et al. (2008) in Guinea fowl, Mostafa et al. (2012) in Avian species, Nasrin et al. (2012) in chicken, Dahekar et al. (2014) in Japanese quail. 4.5 Gross morphology of the gizzard The gizzard was biconvex in shape, dark reddish to brown in colour, situated in the left caudo-dorsal regions of the thoraco-abdominal cavity and placed caudally between the two lobes of the liver. It was much larger and more muscular than the proventriculus. It consisted of a body with two tapering ends, the saccus cranialis and saccus caudalis which were light red in colour (Fig. 1F). The present observations on gross appearance and anatomical location of gizzard are in agreement with the observations of Vaish et al. (2007) in Kadaknath fowl, Hena et al. (2012) and Mostafa et al. (2012) in quail, Hassan and Moussa (2012) in duck and Muhammad et al. (2015) in chicken. 49

71 Results & Discussion Biometry of the gizzard The mean ± SE value of length of gizzard in Frizzled feather and Naked neck were 6.00± 0.46 cm and 5.85± 0.27 cm, respectively. The mean width of gizzard of Frizzled feather and Naked neck were 4.25±0.22 cm and 3.11±0.45 cm, respectively and the mean ± SE value of periphery measured at the greater curvature of gizzard in Frizzled feather and Naked neck were 7.43±0.19 cm and 6.25±0.38 cm, respectively. There was no significant difference (P>0.05) between the mean values of length, width of gizzard in both the breeds. The significant difference (P<0.05) found between periphery of gizzard in Frizzled feather and Naked neck fowls. Similar findings on length of gizzard were also mentioned earlier by Nasrin et al. (2012) in broiler (5.32±0.128 cm) and Muhammad et al. (2015) in Naked neck (5.23 ± 0.35 cm) and Frizzled feather (5.42 ± 0.20 cm), respectively. While, Hassan and Moussa (2012) mentioned that the mean length of the ventriculus in pigeon (3.4 cm) while in duck (6.7 cm). The mean widths of gizzard were recorded earlier by Muhammad et al. (2015) in Naked neck (5.12 ± 0.20) and Frizzled feather (5.08 ± 0.32 cm) which are more or less similar to the observations reported by Hassan and Moussa (2012) and Muhammad et al. (2015) Histology of the gizzard The dense thick secretory material was present on luminal surface of gizzard. Below this layer of secretary material layer of long mucosal glands were present. Muscularies mucosae was absent. There were no partitions between the lamina propria and the submucosa and consisted of loose connective tissue. Musculosa was very thick as it was a muscular stomach. The muscle bundles were separated by connective tissue septae giving mosaic appearance to the muscular layer (Fig. 13). 50

72 Results & Discussion These findings are similar to the report of Mostafa et al. (2012) in common quail and Nasrin et al. (2012) in chicken. 4.6 Gross morphology of the small intestine The small intestine consisted of three segments viz; duodenum, jejunum and ileum. However, there was no clear demarcation between the jejunum and ileum. However, coils were found in the jejunum and absent in the ileum. These observations were similar as described by with Fitzgerald (1969) in Japanese quails, Hodges (1974) in fowl, Ensminger (1992) in avian species. (a) Duodenum The duodenum appeared as an U shaped loop of intestine, directed caudally and upward up to the level of synsacrum. It was light to brown-red in colour with right descending and left ascending part separated by the pancreas within the loop (fig. 1G). The duodenal loop was located in the caudal part of the right side of the abdominal cavity. The pancreas was located between the two parts of duodenum. The duodenum on its left side was related to the right side of gizzard and dorsally it covered jejunum, caecum and ileum whereas, on the right side it was in contact with the right lobe of liver and lateral body wall. Two bile ducts and two pancreatic ducts opened very close to each other into the distal end of the ascending duodenum in both the breeds. The duodenum was held together by a fold of mesentery termed as mesoduodenum. These findings are similar to that described by Getty (1975) in fowl, Igwebuike and Eze (2010) in African pied crow, Hamdi et al. (2013) in black winged kite and Muhammad et al. (2015) in Frizzled feather and Naked neck fowls. 51

73 Results & Discussion (b) Jejunum The jejunum was pale brownish to reddish in color (Fig. 1I). It was the longest segment among the all of the intestine and arranged in the form of coils and suspended by the common mesentery originated at the dorsal part of abdominal cavity. The coils of jejunum were closed to the right abdominal sac, ovary, caecum, ileum, ascending duodenum and pancreas on right side, while it was revealed to ventrally duodenum and gizzard and on left side with liver. Meckel s diverticulum appears as a small projection on the free border of the terminal point of jejunum in both the breeds. The present findings are in agreement with Getty (1975) in fowl and Muhammad et al. (2015) in chicken. However, Igwebuike and Eze (2010) in African pied crow reported that the jejunum was organized in the form of coils, which have centripetal coils, a sigmoid flexure and centrifugal coils. (c) Ileum The ileum was yellowish to gray in color and was and extended from the Meckel's diverticulum of jejunum to the ileoceco-colic junction. There was no clear demarcation between jejunum and ileum in both under the report breeds. The gizzard was seen on the left, jejunum on the right while spleen and ascending duodenum were located ventral to the ileum (Fig. 1J). The present observations are in agreement with Getty (1975) in fowl, Igwebuike and Eze (2010) in African pied crow and Indu et al. (2011) in peafowl Biometry of the small intestine (a) Duodenum The mean ± SE value of length of duodenum of Frizzled feather and Naked neck was 24.0±0.99 cm and 21.5±0.59 cm, respectively. The external diameter of 52

74 Results & Discussion duodenum at origin, at middle and at terminal part in Frizzled feather was 1.80±0.14 cm, 1.9± 0.13 cm and 1.8±0.10 cm, respectively and in Naked neck was 1.75 ± 0.11 cm, 2.1 ± 0.10 cm and 1.8±0.10 cm, respectively. There was no significant difference (P>0.05) between the length and external diameter of duodenum in Frizzled feather and Naked neck fowl. The present observations on length of duodenum in both the breeds are in agreement with Getty (1975) in adult fowl (22-35 cm) while Nasrin et al. (2012) reported that in broiler chicken, the average length of duodenum was 34.13±1.47 cm at 28 th day which are comparatively higher than present value. However, Muhammad et al. (2015) reported that the mean length of duodenum in Naked neck and Frizzled feather were ± 1.17 cm and ± 1.45 cm, respectively which are comparatively lower than the present observations because, in the present study, the live body weight of Naked neck (1.83 ± 0.06 kg) and Frizzled feather (1.75 ± 0.06 kg) was higher than the live body weight of Naked neck ( ± gm) and Frizzled feather ( ± gm) measured by Muhammad et al. (2015). The present findings on external diameter of duodenum are more than with the observations reported by Getty (1975) in adult fowl ( cm) and those reported by Muhammad et al. (2015) in Naked neck (0.43± 0.31 cm) and Frizzled feather (0.10 ± 0.03 cm). (b) Jejunum The mean ± SE value of length of jejunum of Frizzled feather and Naked neck was 98.2±4.06 cm and 87.33±5.10 cm, respectively. The mean ± SE value of external diameter of jejunum in Frizzled feather and Naked neck fowl was 1.6±0.84 cm and 1.8±0.15 cm, respectively. There was no significant difference (P>0.05) between the length and external diameter of jejunum in Frizzled feather and Naked neck fowl. 53

75 Results & Discussion The present observations on length of jejunum in both the birds are in accordance with the previous observations of Getty (1975) in adult fowl ( cm) and comparatively higher (more than double) than the observations reported earlier by Muhammad et al. (2015) in Naked neck (37.42 ± 1.53 cm) and Frizzled feather (35.37 ± 2.93 cm) because of the lower body weight and lower than the observation reported by Nasrin et al. (2012) in chicken at 28 th day (123.50±3.663 cm). It may be due to the age difference. The present findings on external diameter of jejunum are similar with the observations reported by Getty (1975) in adult fowl ( cm) and higher than those reported by Muhammad et al. (2015) in Naked neck (0.10 ± 0.00 cm) and Frizzled feather (0.12 ± 0.02 cm). (c) Ileum The mean ± SE value of length of ileum of Frizzled feather and Naked neck was 18.7±0.77 cm and 20.0±0.96 cm, respectively. The mean ± SE value of external diameter of ileum in Frizzled feather and Naked neck fowl was 1.96±0.18 cm and 1.8±0.17 cm, respectively. There was no significant difference (P>0.05) between the length and external diameter of ileum in Frizzled feather and Naked neck fowl. The present observations on length of ileum are in concurrence with the observations of Getty (1975) in adult fowl (13-18 cm) but the present results are lower than those reported previously by Nasrin et al. (2012) in chicken (31±3.663 cm) and Muhammad et al. (2015) in Naked neck (39.67 ± 1.64 cm) and Frizzled feather (37.13 ± 3.19 cm). The present findings on external diameter of ileum are comparatively more than the observations reported by Getty (1975) in adult fowl ( cm) and those reported by Muhammad et al. (2015) in Naked neck (0.12 ± 0.02 cm) and Frizzled feather (0.10 ±0.00 cm). 54

76 Results & Discussion Histology of the small intestine In the present study, the mucosa presented intestinal villi throughout its length. The epithelial lining was simple columnar in type throughout with goblet cells. The villi in the duodenum were more in height as compared to jejunum and ileum. The intestinal glands or crypts of Lieberkuhn were present throughout the intestine. The Goblet cells were wedged between the columnar cells of villi and crypts of Lieberkuhn. The goblet cells were numerous in ileum than in duodenum in both the breeds. The duodenal glands were absent. The muscularis mucosa was represented by a narrow part of longitudinally arranged smooth muscle fibers towards the side of the submucosa, but on the side of the lamina propria, it was represented by vertically arranged smooth muscle fiber strands. The submucosa was consisted of connective tissue with collagen fibers, elastic fibers, macrophages and blood vessels. The musculosa was made up of inner circular and outer longitudinally arranged smooth muscle fibers. The serosa presented mesothelium (Fig. 14, 15, 16). The present observations are in corroboration with the observations of Bradley and Grahame (1950) in birds, Igwebuike and Eze (2010) in African pied crow, Mostafa et al. (2012) in common quail, Hamdi et al. (2013) in Avian species and Levi et al. (2013) in broiler chicken. 4.7 Gross morphology of the large intestine (a) Caecum The right and left caeca are blind tubes, originated at the ileocolic junction, greyish black in color (Fig. 1K). Each caecum had three main parts terminal blind part, middle part and origin part. Each one was in the form of a bilateral extension of the gut that was directed cranially toward the gizzard. 55

77 Results & Discussion The finding reported in present study on gross morphology of caecum in both the birds are similar to those reported earlier by Mostafa et al. (2012) in quail, Nasrin et al. (2012) and Muhammad et al. (2015) in chicken. (b) Colorectum The colo-rectum was comparatively wide, short, straight and light grey in colour (Fig. 1L). It was the terminal part of the large intestine, extended between the ileo-cecal junctions and terminated into the cloacal chamber, coprodeum. The results of present study on gross morphology of colorectum in both the birds are similar to those reported earlier by Indu et al. (2011) in peafowl, Nasrin et al. (2012) in chicken, Gosomji et al. (2015) in the guinea fowl and Muhammad et al. (2015) in chicken Biometry of the large intestine (a) Caecum In the present study, the mean ± SE value of length of caecum of Frizzled feather and Naked neck fowl was 17.0±1.15 cm and 16.6±0.69 cm. There was no significant difference (P>0.05) between the length of caecum in Frizzled feather and Naked neck fowl. The mean ± SE value of external diameter at origin, at middle and at blind part of caecum of Frizzled feather was 2.2±0.23 cm, 3.1± 0.23 cm and 2.3±0.17 cm, respectively. The mean ± SE value of external diameter at origin, at middle and at blind part of caecum of Naked neck was 1.5 ± 0.04 cm, 2.8 ± 0.19 cm and 2.3±0.25 cm, respectively. There was significant difference (P<0.05) between the external diameter at origin and non significant difference (P>0.05) between the external diameter at middle and at terminal part of caecum in Frizzled feather and Naked neck. 56

78 Results & Discussion These present observations on length of caecum of both the breeds are in agreement with the previous observations of Nasrin et al. (2012) in chicken (18.125±1.732 cm). Whereas, the present values are found to be higher than those of Naked neck (10.25 ± 0.57 cm) and Frizzled feather (11.75 ± 0.91 cm) described by Muhammad et al. (2015) in chicken. While, the present observations on external diameter of caecum are higher than the observations of Muhammad et al. (2015) in Naked neck (0.12 ± 0.02 cm) and Frizzled feather (0.12 ± 0.02 cm). (b) Colo-rectum The mean ± SE value of length and external diameter of colo-rectum in Frizzled feather and Naked neck fowl was 9.7±0.73 cm (L), 8.0±0.52 cm (L) and 2.3±0.22 cm (D), 2.2±0.12 cm (D), respectively. There was no significant difference (P>0.05) between the length and external diameter of Frizzled feather and Naked neck fowl. Similar observations on length of colo-rectum were reported earlier by Nasrin et al. (2012) in chicken (8.83±0.037 cm) and higher than Muhammad et al. (2015) in Naked neck (6.85 ± 0.34 cm) and Frizzled feather (7.13 ± 0.67 cm). While, the present observations on external diameter of colo-rectum in both breeds are found to be higher than observations reported by Muhammad et al. (2015) in Naked neck (0.12 ± 0.02 cm) and Frizzled feather (0.15 ± 0.02 cm) Histology of the large intestine (a) Caecum The mucosal villi were well developed, lined by a simple columnar epithelium and had goblet cells as well as epithelial crypts. The muscularis mucosa was composed of thin layer of longitudinal muscle fibers. The submucosa was narrow and thin. The musculosa consists of two layers of smooth muscle fibres: an outer 57

79 Results & Discussion longitudinal layer and inner circular. The caecum was covered externally with a thin serosal layer (Fig.17). Similar observation was reported on general histological structure of caecum by Mostafa et al. (2012) in common quail. (b) Colo-rectum The mucosa was made up of numerous leaf-like villi which covered by simple columnar epithelium along with goblet cells. The number of goblet cells was more. The mucosal folds were present. The muscularis mucosa was composed of longitudinal muscle fibers. This layer extends inside the mucosal folds. The submucosa consists of loose connective tissue and blood vessels. The musculosa was made up of two muscle layers; an outer thin longitudinal and inner thick circular. The thin layer serosa was present externally (Fig. 18). The present observations are in agreement with the observations reported earlier by Indu et al. (2011) in pea fowl and Mostafa et al. (2012) in common quail. 4.8 Gross morphology of the liver The liver of both the breeds was very fragile, dark red brown in colour consist of right and left lobes. The right lobe was larger, undivided, while the left lobe was small and subdivided into dorsal part and ventral part. The right and the left lobes were united together antero-dorsally by a thin isthmus. It was connected to the pericardium wall by means of the falciform ligament (pericardiaco-hepatic ligament). The gall bladder was partially embedded in the right lobe of the liver at the visceral surface. The parietal surface was strongly convex, facing ventrally and was in relation with ventral body wall. It was the largest organ of the abdominal cavity situated behind the heart from which it was separated by a cardiac notch (Fig. 5). 58

80 Results & Discussion The left lobe had three borders. Anterior right border was convex. Left border was straight and posterior border was slightly concave. Anterior border was in contact with heart. Posterior border was in contact with gizzard while left border was in contact with proventriculus on the left side. Parietal surface was in contact with sternum. The present observations are in agreement with the observations of Clark (2005) in birds, Mostafa et al. (2012) in quail, Ahmed (2015) in Turkey, Javaid et al. (2014) in broiler and Moslem (2015) in poultry Biometry of the liver The mean ± SE value of weight of right lobe of liver in Frizzled feather and Naked neck was 18.1±0.29 gm and 19.7±0.52 gm, respectively. And the mean ± SE value of weight of left lobe of liver in Frizzled feather and Naked neck was 14.06±0.29 gm and 14.4±0.52 gm. The Ratio of total weight of liver in Frizzled feather and Naked neck was 1.7% and 1.9 % in relation with the live body weight. There was significant difference (P>0.05) between the weight of right lobe between both the breeds and non significant difference (P<0.05) between the left lobe of liver in Frizzled feather and Naked neck fowl. However, the right lobe was formed to be larger and slightly heavier than the left lobe. The present observations on weight of liver are higher than the observations reported by Ahmed (2015) in male turkey in which they stated that the weight of liver was 1.89 ± 0.11 % in relation with the body weight and Javaid et al. (2014) in broiler where they mentioned maximum weight of fresh liver of broiler at 6 th week of age, was gm. 59

81 Results & Discussion Histology of the liver The connective tissue (Glisson s) capsule was indistinguishable. Portal triad was not well defined though showed all the structure into it. Central veins were prominent lined by endothelial cells. The hepatocytes were polyhedral and angular in shape with large nucleus. The hepatocytes around the central veins were arranged in radiating cords and later on they were grouped in a cluster of hepatocytes. Sinusoidal space were irregularly arranged and lined by distinct endothelial cells. The presence of the Kupffer s cells with nucleus was well noticed under microscopic examination (Fig. 19). These findings on general histoarchitecture of liver of Frizzled feather and naked neck fowl are similar to the report of Sivagnanam et al. (2004) in Guinea fowl, Ahmed (2015) in Turkey and Moslem (2015) in poultry. The present study showed that the histological structure of liver is similar in both breeds. 4.9 Gross morphology of the pancreas The pancreas was an elongated, pale yellow or brown coloured lobular structure that was found between the ascending and descending duodenal loops (Fig. 1H). It was consisted of dorsal, ventral and splenic main lobes. The dorsal and ventral lobes are long and thin and the splenic lobe was small. The pancreatic and bile ducts open into the ascending part of the duodenum opposite the cranial part of the gizzard (Fig. 7). The present observations are in agreement with the Getty (1975) in fowl. However, Mostafa et al. (2012) in quail and Deprem et al. (2015) in goose stated that the pancreas was divided in to four lobes i.e. the dorsal lobe, ventral lobe, third lobe and splenic lobe. 60

82 Results & Discussion Biometry of the pancreas The mean ± SE value of weight of Pancreas of Frizzled feather and Naked neck was 4.4±0.45 gm and 3.6±0.24 gm. There was no significant difference (P>0.05) between the weight of Pancreas of Frizzled feather and Naked neck fowl Histology of the pancreas The lobules of pancreas were covered by a thin connective tissue capsule with fine septae from it. The pancreatic acini were lined by pyramidal cells. These cells exhibit a basophilic homogenous cytoplasm at base and an eosinophilic granular cytoplasm at apical portion. The centroacinar cells were present in the lumen of the pancreatic acini. The islets of Langerhans were observed. The alpha islet was scattered among lobules or spherical collection, stained very lightly and had capillaries present inside it. The beta islet was similar in appearance to those of the mammalian pancreas, containing few delta cells (Fig. 20). The present observations on the histological structure of pancreas of both the Frizzled feather and Naked neck fowls are in agreement with those reported by Bacha and Bacha (2000) on the histomorphology of Pancreas in chicken. They reported that the Pancreas of the chicken was similar to that of the mammal. 61

83 Summary and Conclusions

84 CHAPTER - V SUMMARY & CONCLUSIONS The present work entitled Gross, Biometrical and Histomorphological Studies on Various Organs of the Digestive system of Frizzled feather and Naked neck Fowls (Gallus gallus domesticus) was carried out at the Department of Veterinary Anatomy & Histology, College of Veterinary Science & A. H., Anand Agricultural University, Anand, Gujarat. For the present study, 12 healthy adult birds include 6 each of Frizzled feather and Naked neck fowls (aging at 14 th weeks) were procured from the Central Poultry Research Station, AAU, Anand and sacrified. The gross observation and photography of the digestive tract for its in situ condition was carried out immediately after opening the bird. The biometrical as well as histomorphological evaluation of the various organs of the digestive system included tongue, oesophagus, crop, proventriculus, gizzard, small intestine viz., duodenum, jejunum and ileum and large intestine viz., right and left caeca and colorectum, liver and pancreas. The histological sections (6 μm) were stained with Haematoxylin and Eosin for routine staining. The following conclusions were drawn from the present study of gross, biometry and histomorphology on the Digestive organs of Frizzled feather and Naked neck Fowls: 1. The tongue of the Frizzled feather and Naked neck fowl was brownish in color and triangular in shape with a pointed apex, a wide base and short body. 2. The body of tongue was attached ventrally with the floor of lower beak and its mucosa was comparatively thinner and smooth. Dorsal surface of was marked by a fade median groove and at the level of root, there was a single row of caudally directed papillae. 62

85 Summ ary & Conclusions 3. The entoglossal process of hyoid bone supported the root of tongue of Frizzled feather and Naked neck fowls. There was no significant difference (P>0.05) between the length of the tongue of Frizzled feather (2.40±0.68 cm) and Naked neck (2.15± 0.09 cm). 4. The mucosal epithelium of tongue was composed of keratinized stratified squamous epithelium which was thick on the dorsum linguae in both the breeds under study. 5. The esophagus in both the breeds was long, narrow and straight collapsible tube extended from the pharynx to proventriculus. It was composed of two parts; cervical part and thoracic part separated by its own diverticulum called crop. Cervical part was comparatively longer than thoracic part in both the breeds. 6. The mean ± SE value of total length of esophagus of Frizzled feather and Naked neck was ± 0.73 cm and ± 0.56 cm. The external diameter was 2.10 ± 0.15 cm and 1.91±0.18 cm (cervical part), 1.91±0.13 cm and 1.75 ± 0.11 cm (thoracic part), respectively. 7. The esophageal wall consists of usual layers of tubular digestive organs, i.e. mucosa, submucosa, musculosa and adventitia or serosa within outward. The mucosa was formed of stratified squamous epithelium of with 7-8 longitudinal folds of various shapes. The submucus glands or esophageal glands were observed in both, the cervical and the thoracic parts of esophagus. The crop was situated at right ventro-lateral aspect to the thoracic inlet in both the breeds. The mucous glands were not found in crop. 8. The proventriculus was small, elongated, spindle shaped and thick walled tube, which was connected anteriorly with oesophagus and posteriorly with 63

86 Summ ary & Conclusions gizzard. There was a constricted area between the proventriculus and gizzard called isthmus. The mean ± SE value of length of proventriculus of Frizzled feather and Naked neck fowl was 4.15±0.14 cm and 3.83±0.10 cm, respectively. 9. The mucosa of proventriculus was showed gastric ridges lined by simple columnar epithelium. Lamina propria was having the superficial mucosal glands. Submucosa was full of large submucosal glands/proventricular glands. 10. The gizzard was much larger and more muscular than the proventriculus and connected with the proventriculus. It was biconvex in shape, dark reddish to brown in colour. The mean ± SE value of length of gizzard in Frizzled feather and Naked neck were 6.00± 0.46 cm and 5.85± 0.27 cm, respectively. The mean width of gizzard of Frizzled feather and Naked neck were 4.25±0.22 cm and 3.11±0.45 cm, respectively. The mean ± SE value of periphery measured at the greater curvature of gizzard in Frizzled feather and Naked neck were 7.43±0.19 cm and 6.25±0.38 cm, respectively. 11. The gizzard was characterized by a keratinized layer of mucosa called cutical. Below this layer, the mucosal glands were present. Muscularies mucosae was absent. The smooth muscle bundles were separated by connective tissue septae giving mosaic appearance to the muscular layer. 12. The small intestine was distinguished into three main parts; duodenum, jejunum and ileum. The duodenum begins at the end of gizzard and forms an elongated loop had proximal descending and distal ascending parts. There was no clear demarcation between the jejunum and ileum. 13. The jejunum was pale brownish to reddish in color and was the longest part of small intestine. It was coiled structure and the coils were held together by the 64

87 Summ ary & Conclusions fold of mesentery. Meckel s diverticulum appeared as a small projection on the free border of the terminal point of jejunum. The ileum was comparatively smaller and straight than other part of intestine in both the breeds. 14. The mean ± SE value of length of duodenum, jejunum and ileum in Frizzled feather was 24.0±0.99 cm, 98.2±4.06 cm, 18.7±0.77 cm, respectively. The mean ± SE value of length of duodenum, jejunum and ileum in Naked neck was 21.5±0.59 cm, 87.33±5.10 cm and 20.0±0.96 cm, respectively. 15. The mucosal villi in the duodenum were more in height as compared to that of jejunum and ileum. The intestinal glands or crypts of Lieberkuhn were present throughout the mucosa of intestine. The goblet cells were numerous in ileum than in duodenum. The duodenal glands could not be found in both the breeds. 16. The right and left caeca, blind tubes, originated at the ileocolic junction, were greyish black in color. The mean ± SE value of length of caecum of Frizzled feather and Naked neck fowl was 17.0±1.15 cm and 16.6±0.69 cm, respectively. 17. The colo-rectum was the terminal part of the large intestine, extended between the ileocecal junction and terminated into the cloacal chamber, coprodeum. The mean ± SE value of length and external diameter of colo-rectum in Frizzled feather and Naked neck fowl was 9.7±0.73 cm (L), 8.0±0.52 cm (L) and 2.3±0.22 cm (D), 2.2±0.12 cm (D), respectively. 18. The liver of both the breeds was very soft, dark red to brown in colour consist of right and left lobes. The right lobe was found to be larger and slightly heavier than the left lobe. 19. The mean ± SE value of weight of right lobe of liver in Frizzled feather and Naked neck was 18.1±0.29 gm and 19.7±0.52 gm, respectively. The mean ± 65

88 Summ ary & Conclusions SE value of weight of left lobe of liver in Frizzled feather and Naked neck was 14.06±0.29 gm and 14.4±0.52 gm, indicated that in both the breeds the right lobe was comparatively heavier than the left lobe. 20. The pancreas was an elongated, pale yellow or brown coloured lobular structure that was found between the descending and ascending duodenal loops. The mean ± SE value of weight of Pancreas of Frizzled feather and Naked neck was 4.4±0.45 gm and 3.6±0.24 gm, respectively. 21. The two bile ducts one from each lobe and two pancreatic ducts opened at the termination of duodenum near the caudal part of gizzard and liver. 66

89 References

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96 Appendix - I

97 Table, 1: Biometrical values (Mean ± SE) of various parameters of digestive organs of Frizzled feather and Naked neck fowls Parameters Frizzled feather (n=6) Naked neck(n=6) Live Body Weight (Kg) ± ± 0.06 Tongue Length (cm) ± ± 0.09 Cervical esophagus Length (cm) ± 0.57* ± 0.44* Cervical esophagus External diameter (cm) ± ± 0.18 Thoracic esophagus Length (cm) ± ± 0.22 Thoracic esophagus External diameter (cm) ± ± 0.11 Distance between the termination of cervical esophagus and origin of thoracic esophagus (cm) ± ± 0.24 Proventriculus Length (cm) ± ± 0.10 Proventriculus Origin ± ± 0.35 External diameter Middle ± ± 0.36 (cm) Terminal ± ± 0.33 Gizzard Length (cm) ± ± 0.27 Gizzard Width (cm) ± ± 0.45 Gizzard Periphery at greater curvature (cm) ± 0.19* ± 0.38* Duodenum Length (cm) ± ± 0.59 Duodenum External diameter (cm) Origin ± ± 0.11 Middle ± ± 0.10 Terminal ± ± 0.10 Jejunum Length (cm) ± ± 5.10 Jejunum External diameter (cm) ± ± 0.15 Ileum Length (cm) ± ± 0.96 Ileum External diameter (cm) ± ± 0.17 Caecum Length (cm) ± ± 0.69 Caecum External diameter (cm) Origin ± 0.23* ± 0.04* Middle ± ± 0.19 Blind end ± ± 0.25 Colo-rectum Length (cm) ± ± 0.52 Colo-rectum External diameter (cm) ± ± 0.12 Liver weight (gm) ± ± 0.66 Liver Right Lobe Weight (gm) ± 0.29* ± 0.52* Liver Left Lobe Weight (gm) ± ± 0.30 Liver weight: Body weight 1.7% 1.9% Pancreas Weight (gm) ± ± 0.24 *indicated the significant difference (P<0.05) between the biometrical value of parameter of digestive organs of Frizzled feather and Naked neck breeds.

98 Appendix - II

99 Fig. 1: Gross photograph of Digestive tract of Frizzled feather showing: A. Tongue, B. Cervical esophagus, C. Crop, D. Thoracic esophagus, E. Proventriculus, F. Gizzard, G. Duodenum, H. Pancreas, I. Jejunum, J. Ileum, K. Caeca, L. Colo-rectum, M. Mesentery

100 Fig. 2: Gross photograph of Crop of Naked neck fowl showing the longitudinal mucosal folds on the mucosal surface. Fig. 3: Gross photograph of luminal surface of Proventriculus of Naked neck fowl showing the luminal openings of proventriculur glands.

101 Fig. 4: Gross photograph of luminal surface of Gizzard in Naked neck showing the thick cutical. Fig. 5: Gross photograph showing the Pancreatic duct (a) and Bile duct (b) of Naked neck fowl.

102 Fig. 6: Gross photograph of Liver of Frizzled feather showing the right lobe (Rt.) and left lobe (Lt.) and cardiac notch Fig.7: Gross photograph of Pancreas of Naked neck fowl showing the lobules after removing from duodenal loop.

103 Fig. 8: Cross section of Tongue of Frizzled Feather. H. & E. Staining. 4X. LEp (d) Epithelium of dorsum lingue ; LP- Lamina Propria; LEp (v) Epithelium of ventral surface; gl- Lingual salivary gland; eb Entoglossal bone; SM- Submucosa; M- Muscle Fig. 9: Cross section of Cervical esophagus of Naked Neck. H. & E. Staining. 10X. L- Lumen; LEp Epithelium; LP- Lamina Propria; Lm- Lamina muscularis; gl- gland;sm- Submucosa; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; Ad- Adventitia

104 Fig. 10: Cross section of Crop of Frizzled Feather. H. & E. Staining. 10X. LEp- Epithelium; LP- Lamina Propria; LM- Lamina muscularis; SM- Submucosa; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; Ad- Adventitia Fig. 11: Cross section of Thoracic esophagus of Frizzled Feather. H. & E. Staining. 10X. LEp Epithelium; Tp- Tunica Propria; mm-muscularis mucosae; Sm- Submucosa; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; Ad- Adventitia

105 Fig. 12: Cross section of Proventriculus of Naked Neck. H. & E. Staining. 4X. LEp Epithelium; Pg Proventricular gland; Lm- Lamina muscularis; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; S- Serosa Fig. 13: Cross section of Gizzard of Frizzled Feather. H. & E. Staining. 4X. K Keratinized layer; Gg- gizzard gland; SM- Submucosa; M- Musculosa

106 Fig. 14: Cross section of Duodenum of Naked Neck. H. & E. Staining. 10X. gc- goblet cell; V- villi; gl gland; SM- Submucosa; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; S- Serosa Fig. 15: Cross section of Jejunum of Frizzled Feather. H. & E. Staining. 10X. gc- goblet cell; V- villi; gl- gland; Lm- Lamina muscularis; SM- Submucosa; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular

107 Fig.16: Cross section of Ileum of Frizzled Feather. H. & E. Staining. 10X. V- villi; gl gland; Lm- Lamina muscularis; SM- Submucosa; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; S - Serosa Fig. 17: Cross section of Caecum of Frizzled Feather. H. & E. Staining. 10X. gc- goblet cell; V- villi; gl gland; SM- Submucosa; Lm- Lamina muscularis; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; S- Serosa

108 Fig. 18: Cross section of Colo-rectum of Naked Neck. H. & E. Staining. 10X. V- villi; gl gland; SM- Submucosa; Lm-Lamina muscularis; M- Musculosa; OL- Outer Longitudinal; IC- Inner Circular; S- Serosa

109 Fig. 19: Section of Liver of Frizzled Feather showing Central vein, Hepatic cells, Kupffer cells and Sinusoid. H. & E. Staining. 40X. Fig.20: Section of Pancreas of Frizzled Feather showing PA- Pancreatic Acini and IL- Islets of Lengerhans. H. & E. Staining. 10X.