Biometrical Study of the Genitalia of Kano Brown Goats and Yankasa Sheep Abu Adakole Hyacinth* 1, Ahemen Terzungwe 2, Ojabo Leo Daniel 3 and Nzere Jeremiah Oluwabamise 1 1 - Department of Veterinary Physiology, Pharmacology and Biochemistry, College of Veterinary Medicine, Federal University of Agriculture, PMB 2373, Makurdi, Benue state, Nigeria 2 - Department of Animal Breeding and Physiology, College of Animal Science, Federal University of Agriculture, PMB 2373, Makurdi, Benue state, Nigeria 3 - Department of Animal Health and Production, College of Veterinary Medicine, Federal University of Agriculture, PMB 2373, Makurdi, Benue state, Nigeria * Correspondence: Email adakoleabu1@gmail.com; Telephone - +234(0)8060396898 Abstract Aim: To determine biometry of the female genitalia of Kano Brown goats and Yankasa sheep. Materials and Methods: Ninety-three samples (66 caprine and 27 ovine samples) of the entire reproductive tracts were collected and evaluated for biometrical dimensions. Results: There was no significant difference in ovarian biometry of the sheep and goat, except the differences in their widths and weights. Biometry of the vagina and cervix agrees with established documentation. Pregnancy did not affect length of the uterine body but increased length of the uterine horns. Non-pregnant uterine horn of the ewe was greater than doe s in length and weight. Conclusion: It is inferred that biometrical status of female genital tract is essential in artificial insemination, and pregnancy diagnosis. Key words: biometry, genitalia, goat, pregnancy, sheep Introduction: Sheep and goats are closely related as both small ruminants are in the subfamily Caprinae. However, they are separate species, and so hybrids rarely occur. According to (Adebowale, 2012), the population of sheep and goats in Nigeria is estimated at 22 million and 34.5 million respectively, with a significant population of the animals concentrated in the Northern part of the country. Sheep and goats are sources of animal protein, skin, manure, income and as security against crop failure (Ozung et al., 2011; Fasae et al., 2014). Yankasa and Kano Brown are recognized breeds of domestic sheep and goat in Nigeria. Yankasa is the most widely distributed, and perhaps the commonest breed of sheep in Nigeria, predominantly found in the northern region of the country. It is medium sized, has a typical white coat-colour with black patches around the eyes, ears, muzzle, and sometimes feet (Salako, 2013). Rams have curved horns and a hairy white mane and ewes are polled. The tail is long and thin, the ears are moderately long and somewhat droopy. On the other hand, distribution of the goat breeds in the country showed that Kano Brown goats are predominantly found in Northern part of the country. This breed is believed to be a strain of the Red Sokoto goat. Kano Brown goat is characterized by its uniform brown coat colour, short and horizontal ears and horns in both sexes (Salako, 2013).
Reproductive performance is economically important in small ruminants because of its effect on the number of offspring produced per year (Zewdie and Welday, 2015). Knowledge of biometrical status of female genital tract reveals the overall wellbeing of the animals and is essential in the performance of artificial insemination, pregnancy diagnosis and in dealing with problems of infertility (Jaji et al., 2012). In other countries, studies on morphology, physiology and pathology of reproductive organs of small ruminants (Kunbhar et al., 2003; Kumar et al., 2004; Gupta et al., 2011; Hashem et al., 2015) have been reported. There is however, lack of wealth of information on the reproductive biometry of local Nigerian small ruminants. Therefore, the present study was planned with the aim to add to the body of knowledge on the normal dimensions of different segments of the reproductive tract of the Kano Brown goat and Yankasa sheep in Nigeria. Materials and Methods: Sixty-six caprine and twenty-seven ovine samples of the entire female reproductive tracts were collected from the Wurukum abattoir in Makurdi, Nigeria. The ante-mortem examination was conducted to ensure that the animals were healthy. Any sample that appeared pathological on gross examination was discarded. Normal samples were then were collected, tagged for identification, and conveyed to the laboratory for evaluation. Different segments of the reproductive tracts were examined under bright light and measured. The lengths and diameters were determined using Meter rule or Vernier caliper and recorded in centimeters. The weights of the ovaries and segments of the tracts (in grams) were measured using an electronic weighing balance (Ohaus Adventurer, United States of America). Statistical analysis: Data were expressed as mean ± standard error of mean and subjected to one-way ANOVA using the software, Graph Pad Instat at a 5% level of significance. Results and Discussion: Table1shows the comparative ovarian biometry of Kano Brown goat does and Yankasa ewes. There were no statistical differences in the lengths, widths and weights of the right and left ovaries between the ewes and does examined in this study. Measuring the genital tract
Left ovary with Corpus luteum about to be measured by a vernier caliper However, there was a marked difference in comparative weights between the left ovaries of ovine and caprine, with the caprine having a higher weight (Table 1). In Kano brown goats, mean length of the left ovary was similar to the report (1.71 ± 0.27 cm) found by other researchers (Adigwe and Fayemi, 2005), but was significantly higher than the finding (1.410 ± 0.026 cm) in Black Bengal goats Gupta et al (2011). The length of non-pregnant uterine body agrees with the observation of Sisson and Grossman (1975). The differences might be due to breed and seasonal variations. The mean length (1.65 ± 0.05 cm), and width (0.76 ± 0.04 cm,) of the left ovary of the doe as determined in the present study were lower than earlier findings Jaji et al (2012) in the adult non- pregnant Sahelian goat. However, the mean weight (1.10 ± 0.09) was higher than the figures reported by these authors Jaji et al (2012). Table 1: Ovarian biometry of Kano Brown goat does and Yankasa ewes. Organ Dimensions (Mean± SEM ) EWE DOE < 2 years >2 years < 2 years >2 years Left Ovary 1.4 ± 0.07 1.5 ± 0.23 1.5 ± 0.06 1.8 ± 0.1 Width 0.58 ± 0.05 a 0.58 ± 0.06 a 0.72 ± 0.07 a 0.67 ± 0.1 a Weight (g) 0.71 ± 0.11 a 0.96 ± 0.29 0.89± 0.09 a 0.96 ± 0.29 Right Ovary 1.4 ± 0.07 1.4 ± 0.17 1.5 ± 0.05 1.7 ± 0.08 Width 0.62 ± 0.07 0.63 ± 0.04 0.71 ± 0.04 0.69 ± 0.04 Weight (g) 0.69 ± 0.12 0.87 ± 0.07 0.93 ± 0.07 0.89 ± 0.07 P<0.05; Rows with same superscripts indicate statistically significant pairs of data. In the present study, the lengths of the left and right ovaries were 1.65 ± 0.05 and 1.52 ± 0.04 cm respectively. These values were higher than 1.5 cm reported for small ruminants Sisson and Grossman (1975), but shorter than 2.2 cm reported by Smith (1986) in goats. The length of the right ovary of the doe (1.52 ± 0.04 cm) was relatively lower than that found in a study by Adigwe and Fayemi (2005), while the width (0.70 ± 0.03 cm) was similar to the finding (0.66 ± 0.22 cm) found by the same study. The mean length (1.53 ± 0.08 cm), width (0.62 ± 0.04 cm), and weight (0.77 ± 0.08 cm) of the left ovary of the ewe were generally lower than the results in the Balami ewe studied Jaji et al (2012). In this study, the right ovary of the ewe had 1.446 ± 0.05 cm, 0.6522 ± 0.03 cm, and 0.8109 ± 0.08 g as the values for the length, width, and weight respectively. These values were higher than the results of these investigators Jaji et al (2012). The variations might be due to sample size and breed variations. There was no statistically significant difference (P>0.05) in the comparative weight, width and length between the left and right ovaries. This is at variance with the report of other researchers Islam et al (2007) who found that the mean weight, length and width were distinctly higher in right ovaries (0.66 ± 0.02) g, (1.17 ± 0.02) cm and (0.77 ± 0.02) cm respectively. There was no statistically significant difference (P>0.05) in the uterine lengths of non-gravid and gravid does and non-gravid and gravid ewes. There was also a difference in the uterine lengths and weights of non-gravid ewes and non-gravid does (Table 2). There was no difference in the horn lengths between the non-gravid doe and non-gravid ewe (Table 2). There was however statistical difference in the horn weights of gravid and non-gravid does and ewes. The length of the nonpregnant caprine uterine body of 2.01 ± 0.11 also agreed with previous reports (Sisson and Grossman, 1975) indicating that the length of uterine body to be about 2 cm. However, it is slightly lower than the value (2.5 ± 0.11 cm) reported in Black Bengal goats Gupta et al (2011) and is lower than the
value of 5.83 cm reported by Adigwe and Fayemi (2005). The length of the non-pregnant uterine body of the ewe was found to be 2.175 ± 0.25 cm, significantly lower than the 8.67 ± 1.21 cm found in a previous study Jaji et al (2012). This study found the left horn to be longer in both species and agreed with Adigwe and Fayemi, (2005) who found the length of left and right horns to be 14.4 ± 1.0 and 14.2 ± 1.3 cm respectively. The mean length of uterine horns for goats and ewes in this study (Table 2) agrees with the value found in Black Bengal goats Gupta et al (2011). It was also within the range (10-12 cm) reported in small ruminants Sisson and Grossman (1975). Comparatively, a higher value was reported in Red Sokoto goats Adigwe and Fayemi (2005). There was no statistical difference in both the lengths and weights of cervix between non-gravid does and non-gravid ewes. There was however a significant difference between the cervical lengths of nongravid and gravid ewes (Table 2). There was no statistically significant difference in the lengths of the vagina of ewes and does examined. However, vaginal weights of the non-pregnant ewe and doe were different (Table 2). In both species, pregnancy did not affect the length of the uterine body, but increased the horn length. This finding is in agreement with the progressive increases observed during gestation Jaji et al (2012). The mean lengths of vagina and cervix of the adult non-pregnant goat agreed with previous report Adigwe and Fayemi (2005). Table 2: Biometry of tubular reproductive tracts of Kano Brown goat does and Yankasa ewes Organ Uterine Body Dimensions (Mean ± SEM) Ewe Pregnant 3.33 ± 0.52 >2 years 2.7± 0.54 Doe Nonpregnant < 2 years 2.18 ± 0.25 b 1.8± 0.23 Pregnant Nonpregnant 2.35± 2.01± 0.22 a 0.11 ab < 2 years 2.1 ±0.12 >2 years 2.1 ±0.21 Weight (g) 48.25 ± 8.11 25.76 ± 18± 4.54 a 2.0 28± 5.7 69.98± 10.02 18.94 19±1.4 24±3.6 ±1.36 a Left Horn Uterine 15.70 ± 1.30 12.64 ± 0.91 11± 1.1 15± 1.8 20.01± 1.03 12.71± 0.74 13±0.71 15±1.5 Weight (g) 25.29 ± 10.44± 1.04 ab 8.8± 0.99 13± 2.3 22.10± 3.11 c 8.95± 0.71 bc 8.8±0.77 12±1.8 6.10 a Right Horn Uterine 16.37 ± 1.87 12.41 ± 0.92 11±1.1 14± 1.9 19.51± 1.36 a 12.48± 0.69 a 13±0.72 14±1.6 Weight (g) 22.95 ± 5.34 a 11.27± 1.50 ab 8.8± 0.97 15± 3.7 23.06± 4.21 c 10.0± 0.70 bc 9.8±0.74 12±1.8 Cervix 5.50 ± 0.40 a 5.40 ± 0.34 a 4.4± 0.09 6.6± 0.75 4.31± 0.16 4.78± 0.16 4.6±0.21 4.8±0.22 Weight (g) 10.70 ± 1.55 8.36 ± 0.74 5.6± 0.61 11± 1.1 8.40± 0.70 7.16± 0.37 6.7±0.55 8.3±0.43 Vagina 4.53 ± 0.51 6.95 ± 1.01 4.0± 0.34 4.9± 0.81 4.32± 0.32 4.30± 0.19 4.5±0.26 4.1±0.61
Weight (g) 7.08 ± 0.94 4.37 ± 0.34 a 5.1± 0.81 9.0± 2.3 5.61± 0.62 5.78± 0.43 a 5.6±0.58 7.2±0.9 P<0.05 Rows with same superscripts are statistically significant. The mean lengths of the vagina and cervix of the adult non-pregnant goat from this study agree with the figures (5.32 ± 0.34 and 2.59 ± 0.61 cm) obtained in non-pregnant female Red Sokoto (Maradi) goats Adigwe and Fayemi (2005). It also agrees with the length of cervix (5.05± 1.09 cm) in the nonpregnant Sahelian goat Jaji et al (2012). The values obtained for the lengths of the vagina and cervix were however, shorter than the values of 7.30 and 5.50 cm for the respective organs in goats Smith (1986). Differences may be due to the anatomy of the sheep cervix being highly variable between animals and may explain the variations in success rate of transcervical artificial insemination between individual animals Kershaw et al (2005). Breed, age, parity and physiological state influence the length of the ovine cervix. The mean length of the cervical canal has been described as 5.5 and 6.7 cm (Halbert et al., 1990) respectively and the length ranges from 5.7 to 10 cm indicating the high variability between individuals. Conclusion: Differences in the dimensions of various segments of reproductive tract of goats and ewes might have been due to breed differences. It is inferred that biometrical study of the female genital tract is essential in artificial insemination, and pregnancy diagnosis. Competing interest: The authors declare that they have no competing interests. References 1. Adebowale O. A. L. (2012). Dynamics of ruminant livestock management in the context of the Nigerian Agricultural System. In: Livestock Production (Eds. Khalid Javed). Intech. USA. ISBN978-953-51-0814-6. pp 61. 2. Adigwe P. I. and Fayemi O. (2005). A biometric study of the reproductive tract of the Red Sokoto (Maradi) Goats of Nigeria. Pakistan Veterinary Journal 25(3) 149-150 3. Fasae O. A., Oduguwa B. O., Adejumo L. A., Makinde T. E. and Sanwo K. A. (2014). Carcass and Meat Characteristics of Traditionally Managed Nigerian Yankasa and West African Dwarf Breeds of Sheep. Pertanika Journal of Tropical Agricultural Sciences 37(1): 101-108 4. Gupta M. D., Akter M. M., Gupta A. D. and Das A. (2011). Biometry of female genital organs of Black Bengal goat. International Journal of Natural Sciences 1: 12-16 5. Halbert G., Dobson H., Walton J. and Buckrell B. (1990). The structure of the cervical canal of the ewe. Theriogenology 33: 977-992 6. Hashem N. M., El-Zarkouny S. Z., Taha T. A. and Abo-Elezz Z. R. (2015). Oestrous response and characterization of the ovulatory wave following oestrous synchronization using PGF 2α alone or combined with GnRH in ewes. Small Ruminant Research 129: 84 87 7. Islam M. R., Khandoker M. A., Afroz S., Rahman M. G. M., and Khan R. I. (2007). Qualitative and quantitative analysis of goat ovaries, follicles and oocytes in view of in vitro production of embryos. J Zhejiang University Science Bulletin 8(7):465-469
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