Arch. Tierz., Dummerstorf 49 (2006) Special Issue, Department of Poultry Breeding, Agricultural University of Szczecin, Poland

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1 Arch. Tierz., Dummerstorf 49 (2006) Special Issue, Department of Poultry Breeding, Agricultural University of Szczecin, Poland ZOFIA TARASEWICZ, MAREK LIGOCKI, DANUTA SZCZERBIŃSKA, DANUTA MAJEWSKA and ALICJA DAŃCZAK Different level of crude protein and energy protein ratio in adult quail diets Abstract The experiment allowed us to evaluate the influence of low-protein diet feeding on the performance, health, and egg quality of Pharaoh Japanese quails. The control-group quails were fed on layers complete mash diet containing 21 crude protein, with an energy-protein ratio 0.56:1. The treatment groups II and III were fed on the diet containing 19 crude protein and having different energy-protein ratios, respectively 0.61:1 and 0.56:1. Laying performance achieved in group III did not differ significantly from that of the control quails, whereas that of group II was significantly lower compared to the other groups. The diet with reduced crude protein and increased energy-protein ratio (group II) resulted in statistically highly significant decrease in body weight as compared with the control and group III. Group II quails consumed significantly (P<0.01) the most feed to produce 1 egg as well as 1 kg of eggs. Low-protein diets did not affect most of the quality parameters of eggs. No influence of the diets could be observed in relation to dry matter content or crude protein level in either yolk or white of egg. Key Words: low-protein diets, quails, performance indices, egg quality Introduction The experiment is a part of a complex research project focused on application of lowprotein diets in quail feeding. Changes in the life style of people in many countries as well as their growing and diversifying purchase power cause that the consumers start to demand less common poultry products of ostriches, emus, or quails. However, on the other hand, many consumers expect the producers to offer lower prices for food products, which can be achieved by reducing the cost of production. One of the ways leading to reduced cost of feeds is to reduce their protein content. The breeds and varieties of quails farmed presently are characterized by quite a wide range of dietary requirements. The poultry is also able to adapt to lowered supply of nitrogen in the diet through their better management of its compounds. Another significant, ecological aspect of low-protein diet feeding is that the reduced amount of nitrogen is discharged into the environment with manure (SZCZUREK and PISULEWSKI, 1996). JAMROZ et al. (1984) as well as LECLERCQ and TESSERAND (1993) have not observed any negative influence of moderately reduced level of crude protein in the diet, on the performance or slaughter value of chicken broilers. Similar results for quails were reported by DASZKIEWICZ et al. (1998). ZELENKA et al. (1984), who applied feeding with varied crude protein level, did not demonstrate significant differences in the breast muscle content or carcass fat content in quails. Conversely, limited feeding, as opposed to ad libitum feeding, resulted in differences in the composition of body tissues and in slightly delayed laying. The aim of this study was to investigate the influence of diets with crude protein level reduced to 19 and with two different energy-protein ratios on the laying performance, feed intake, and egg quality of Pharaoh quails.

2 326 Material and Methods The experiment was carried out on 120 adult Pharaoh quails (during the period between 6 and 25 th weeks of age), of which three feeding groups were formed with five subgroups, eight birds each. The experiment was performed in the facilities of the Department of Poultry and Ornamental Bird Breeding, the Agricultural University of Szczecin, Poland. The quails were self reared and were raised under optimal microclimate conditions. The diet consisted of feed mashes of the nutritional value corresponding to the recommendations of NUTRIENT REQUIREMENTS OF POULTRY (1996). In the 6 th week of age, the birds were weighed individually and were distributed to the three groups so as each group comprised birds of similar body weight. The quails were kept in cages throughout the experiment in the room at C and under light regime subject to natural changes, but with light available for not less than 17 hours a day. The diet of group I (control) was a mash containing 21 crude protein and 11.7 MJ of metabolic energy (according to NUTRIENT REQUIREMENTS OF POULTRY, 1996), whereas in groups II and III, respectively, 19 crude protein and 11.7 MJ of metabolic energy and 17 crude protein and 10.6 MJ of metabolic energy. Experimental mashes (applied in groups II and III) differed also in the energy-protein ratio. In group II it was 1:0.61, while in group III 1:0.56, thus it was just like that in the control (I). The chemical composition of the diets has been presented in Table 1. Table 1 Chemical composition of quail feed mixes ( ) Matabolizable energy MJ/kg Protein crude Energy to protein ratio Fibre crude Calcium Available phosphorus Na Lysine Methionine + cystine :0.56 1:0.61 1: All the birds were fed ad libitum, and the feed refusals were weighed once a week. The quails also had unlimited provision of water. The experiment tooks 19 th weeks, during which laying performance, egg weight, deaths rate, and feed consumption were recorded. In the final stage of the experiment, the layers were individually weighed to record their final body weights, and egg quality evaluation was carried out. For this purpose, 25 eggs from each group were collected. The evaluated quality traits of eggs involved: specific gravity, which was determined in sodium chloride solutions of density ranging from g/cm 3 to g/cm 3 (increasing gradually by unit), egg shape index, and index of white and yolk, as well as ph of white and yolk using a Sentron 3001 ph-meter. Dry matter content and crude protein were assayed in both yolk and white through proximate

3 327 analysis. From each group, 11 quails were slaughtered and examined post-mortem in order to determine the influence of feeding the diet poorer in protein on the development of selected internal organs. Liver, pancreas, caecum, and small intestine were dissected and their proportion in the body weight was calculated. The data were analysed statistically (using the Statistica package). Significance of differences between groups was tested using one-way ANOVA with the Duncan test (STATISTICA Software). Results In the 25 th week of age, the highest body weights were attained by the females of group III (210.0 g), and these did not differ significantly from the control group quails (208.4 g). Significantly lower body weights were recorded in group II, as compared with the other groups (187.9 g), in which the birds received the mixture containing 19 protein and with extended energy-protein ratio (Table 2). The quails of group II consumed daily the most feed, 29.1 g. Group II quails used the most feed to produce an egg (42.8g), highly significantly higher than in the remaining groups. Similar was the feed consumption per 1 kg of eggs. In the group of quails that received the mixture containing 19 protein and with extended energy-protein ratio it was higher by about 16 and 12 in relation to, respectively, group I and III (Table 2). Table 2 Body weight, feed conversion Body weight of female in 6 week g ± ± ± 16.0 Body weight of female in 25 week g A ± B ± A ± 19.6 Feed intake g/quail/day 28.0 ± ± ± 1.30 Feed conversion g/egg 36.9 A ± B ± A ± 6.05 kg/kg eggs 3.19 A ± B ± A ± 0.58 a,b - differences significant at P<0.05; A,B - differences significant at P<0.01 (also for Tables 3-6). Table 3 Laying usefulness indicators Egg production to 25 week of life: number/quail 98.1 A ± A ± B ± B ± A ± A ± 8.4 Average number of eggs in week (number/quail) 5.60 A ± B ± A ± 0.59 Average egg weight in whole research period (g) 11.2 ± ± ± 0.19 Egg shape index 1.30 ± ± ± 0.11 The highest mean egg production per layer during the studied period was obtained from the birds of the control group, 98.1 eggs, only by some 2 eggs more than in group III, where the diet contained reduced protein level and with unchanged energy-protein

4 328 ratio. These two groups exhibited increased laying rates, statistically highly significantly (p < 0.01) higher compared to group II. Similar values were recorded for the mean weekly number of eggs per layer (Table 3). All three groups produced eggs of similar weight over the entire period of the experiment; an average egg weight was 11.2 g, with no significant differences. Yolk proportion was the highest in group III, 31.2, whilst the lowest in group I, 29.3, with significant differences only between groups I and III, both in the proportion of white and yolk in egg mass (Table 4). Table 4 Morphological composition of quail eggs Egg weight g 11.2 ± ± ± 0.57 White weight g 6.86 ± A ± ± A,B ± ± B ± 1.36 Yolk weight g 3.29 ± a ± ± b ± ± b ± 1.43 White to yolk ratio 2.08 : : : 1 Table 5 Qualitative traits of quail eggs Specific gravity g/cm ± ± ± White height mm 5.26 ± ± ± 0.65 White shape index ± ± ± Yolk shape index 0.45 ± ± ± White ph 9.17 A ± A ± B ± 0.10 Dry matter White content 12.7 ± ± ± ± ± ± 0.53 Yolk ph 6.48 A ± A ± B ± 0.11 Dry matter White content 53.4 ± ± ± ± ± ± 0.35 Eggs obtained from the layers fed on diets differing in protein did not differ significantly in relation to a majority of the studied traits. The level of white, which is an index of its density, was the highest in group II eggs (5.74 mm), while the white index was similar in all groups. Yolk index, on the other hand, was the same in eggs of both treatment groups (0.41), and slightly higher in the control group (0.45), the differences, however, being non-significant (Table 5). However, statistically

5 329 significant differences in ph of an egg yolk and white were stated. The reduced level of the proteins in mixture maintaining however the energetic and protein relation as in the control mixture, caused the depreciation of ph of an egg yolk and white. Reduced protein level in the diet with unchanged energy-protein level, as in the control, resulted in highly significant reduction of white and yolk ph. On the other hand, it did not affect the level of dry matter and crude protein in the yolk and white of egg. Table 6 Participation of some internal organs in relation to body weight Body weight g A ± B ± A ± Liver 3.01 ± ± ± 0.34 Pancreas 1.25 a ± b ± a ± 0.16 Small intestine 1.34 A ± B ± B ± 0.16 Caecum 0.71a ± a,b ± b ± 0.24 No significant differences were found in the liver percentage between the groups, which ranged between 3.01 (group I), and 3.40 (group II). The percentage of pancreas in the body weight was the highest in group II birds (1.52). In relation to the remaining groups, these differences were statistically significant, p < Higher proportion of small intestine was found in the treatment groups II and III, respectively, 1.77 and The values attained in these groups did not differ significantly from each other, whereas differed highly significantly from the control, in which the proportion of small intestine was lowest (1.34). Caeca proportion in the body weight was also higher in the treatment groups, with significant (p < 0.05) differences recorded between groups III and I (Table 6. Discussion The performance recorded in our experiment implies that the experimental diet with extended energy-protein ratio had a negative influence on the body weight of birds and that there are no contraindications as to feeding a mixture with reduced protein level, however, with unchanged energy-protein ratio as in a standard mash. In our previous experiment it was found that the protein level in the diet had no influence on the body weight of the quails and their mortality. Reduced level of protein to 17 resulted, however, in a significant drop in laying performance, lower egg weights, and poor egg quality. Feed consumption per 1 kg of eggs was also the lowest if the diet containing 17 crude protein was applied (TARASEWICZ et al., 2006). Other authors, who applied protein restrictive feeding, found that the energyprotein ratio and amino-acids level had a stronger influence on performance than the protein level (ALAO and BALNAVE, 1985; COON et al., 1981). The results of our studies correspond to those by ŚWIERCZEWSKA et al. (2000) on chicken broilers. In the quail experiment carried out by ZELENKA et al. (1984), who applied feed mixtures with varied protein level during raising, no significant influence of the diets on the breast muscles content was found. GEBHARDT-HENRICH and MARKS (1995) observed lower body weight in quail fed on restrictive feeding; in two

6 330 weeks after completion of the limited feeding, however, the body weight returned to normal. Our experiment has not revealed increased mortality of layers, and the recorded deaths were still due to mechanical injuries (wedging a wing in the cage mesh). No influence on the mortality of quails has also been presented by SEHU et al. (2005). De FREITAS et al. (2005) prove that quails regulate feed intake depending on the level of energy in the ration. These authors observed better feed use in the diet containing less energy. Conversely, SEHU et al. (2005) recorded significantly higher consumption and use of feed in groups of lower energy value. According to DE FREITAS et al. (2005), high laying rate can be achieved on diets containing 18 crude protein and 2585 kcal metabolic energy per kg. On the other hand, SEHU et al. (2005) confirm the lack of significant influence of diets containing varied level of crude protein and energy on this performance parameter and egg quality. They noted, however, a significant influence of feed mixture on the egg weight. In the groups where quails were fed more energetic feeds, significantly higher egg weights were achieved. This did not find confirmation in the studies of DE FREITAS et al. (2005). These authors found a trend of the egg weight to increase under growing dietary protein level and a trend to diminish the weight of egg when the energy content increased. ABOUL-ELA et al. (1992) have found an increase in the egg weight with an increasing level of protein in the diet, with a significant increase up to 18 in the light strains and to 21 in the heavy strains. In the analysed experiment, the quail layers were treated as both production fowl and as an experimental model of hen layers. It is possible to feed adult quails on mixtures with protein and energy levels reduced in relation to the standard feed mixtures of the nutritional value recommended by NUTRIENT REQUIREMENTS OF POULTRY (1996) without a negative influence on most performance parameters (feed intake, laying rate, egg weight, egg quality). It has been demonstrated that not the protein level, but rather the energy-to-protein ratio is the chief factor of quail performance. References ABOUL-ELA, S.; WILSON, H.R.; HARMS, R.H.: The effects of dietary protein level on the reproductive performance of bobwhite hens. Poult. Sci., 71 (1992), ALAO, S.J.; BALNAVE, G.: Nutritional significance of different fat sources for growing broilers. Poult. Sci., 64, (1985), COON, C.; BECKER, W. A.; SPENCER, J. V.: The effect of feeding high energy diets containing supplemental fat on broiler weight gain, feed efficiency and carcass composition. Poultry Science 60 (1981), DASZKIEWICZ, T.; PUDYSZAK, K.; MEHLER, Z.; MIKULSKI, D.: Effect of feeding with mixtures of varied nutritional value on chemical composition and physicochemical and sensory properties of quail meat. Zeszyty Naukowe PTZ, (in Polish), 36 (1988), DE FREITAS, A.C.; DE FÁTIRNA FREIRE FUENTES, M.; FREITAS, E.R.; SUCUPIRA, F.S.; DE OLIVEIRA, B.C.M.: Dietary crude protein and metabolizable energy levels on laying quails performance. Revista Brasileira de Zootecnia 34, (2005), GEBHARDT-HENRICH, S.G.; MARKS, H.L.: Effects of feed restriction on growth and reproduction in random bred and selected lines of Japanese quail. Poult. Sci., 74 (1995), JAMROZ, D.; SCHLEICHER, A.; FRITZ, Z.; JAROSZ, L.: Reduction of crude protein level in the concentrates for chickens inter-strain hybrids.zeszyty

7 331 Naukowe AR Wrocław, (in Polish), 26 (1984), LECLERCQ, B.; TESSERAUD, S.: Possbilites de reduction des rejets azotes en aviculture. INRA.Prod. Anim., 6(3), (1993), NUTRIENT REQUIREMENTS OF POUTRY.: Nutritive Value of Feeds. IInd ed. The Kielanowski Institute of Animal Phisiology and Nutrition (Editor), Jabłonna (in Polish), (1996), 88 SEHU, A.; CENGIZ, O.; CAKIR, S.: The effects of diets including different energy and protein levels on production and quality in quails. Indian Veterinary Journal, 82, (2005), STATISTICA software: Copyright StatSoft Polska, , SEWSS, SEDAS, Data Miner, SEPATH and GTrees are trademarks of StatSoft, ŚWIERCZEWSKA, E.; NIEMIEC, J.; MROCZEK, J.; SIENICKA, A.; GRZYBOWSKA, A.: Effect of feeding chickens with mixtures differing in protein content on performance, tissue composition of carcasses, and chemical composition of meat. Zeszyty Naukowe Przeglądu Hodowlanego, Chów i hodowla drobiu, (in Polish), 49 (2000), SZCZUREK, W.; PISULEWSKI, P.: Performance indices and nitrogen load in the manure of chicken broilers fed on low-protein feed mixtures enriched with pure amino-acid supplements. Zeszyty Naukowe Zootechniki AR Kraków, (in Polish), 23 (3) (1996), TARASEWICZ, Z.; SZCZERBIŃSKA, D.; LIGOCKI, M.; MAJEWSKA, D.; WIERCIŃSKA, M.; ROMANISZYN, K.; KAŁKA M.: The effect of different protein level in feeds on the performance of reproductive quails. Animal Science Papers and Reports, Supl. 1, (2006), in press ZELENKA, D.J.; CHERRY, J.A.; NIR, I.; SIEGEL, P.B.: Body weight and composition of Japanese quail (Coturnix coturnix japonica ) at sexual maturity. Entrez Pub.Med, 48 (1), (1984), Authors address Dr habil. ZOFIA TARASEWICZ Dr ing. MAREK LIGOCKI Dr habil. DANUTA SZCZERBIŃSKA Dr ing. DANUTA MAJEWSKA Prof. dr habil. ALICJA DAŃCZAK Agricultural University of Szczecin, Department of Poultry Breeding Ul. Dr Judyma SZCZECIN, POLAND