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English :
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Studies on protein requirements of broiler chicks in a tropical climate
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Arabic :
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دراسات على الاحتياجات من البروتين لكتاكيت التسمين في الظروف الحارة.
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| Abstract |
The present study was conducted in the Department of Animal Production, Faculty of Agriculture, Zagazig University. The experimental work was carr'ied out in Poultry Farm at El-Dawahriya Village, Zagazig, Sharkiya Province, Egypt, during July, August and 10 September 1996.
Design of experiments:
A factorial design 2 x 2 was carried out to study the effect of different levels of protein and total sulphur amino acids on the performance of A vine broiler chicks day-old during the starting (1-28 days) and growing (29-49 days) periods.
In the starting period of the study (1-28 days of age), a total of 720 survived chicks aged one day were randomly divided into 2 equal groups, similar in initial body weight. Each group contains 180 chicks, divided also randomal to sex sub-groups, equal in number (30 chicks in each).
The first group of the starter diet contained23% CP and 2850 Kcal ME/Kg feed to produce C/P ratio 124 Kcal ME/CP where TSAA % was 0.47 and as % of CP was 3.28.
The 2nd group of the starter diet contained 21.0% CP and 2838 Kcal
ME/Kg feed to produce C/P ratio 135 Kcal ME/CP%, where TSAA% was 0.68 and as % of CP was 3.24.
The first sub-group of starter diet contained 23% CP and 2846 Kcal
ME/Kg feed to produce C/P ratio 124 Kcal ME/CP% and inclusion of 0.1% methionine where become TSAA% was 0.84 and as % of CP was 3.65.
The second sub-group of the starter diet contained 21.0% CP and 2835 Kcal ME/Kg feed to produce C/P ratio 135 Kcal ME/CP% and inclusion 0.1 % of methionine where TSAA % was 0.78 and as % of CP was 3.71.
In the growing period of the study, a factorial design 3 x 2 (3 dietary
protein levels x 2 methionine supplementation) was carried out. A total of
695 chicks, which was residual a live from the starting period. Each group divided also randomly as shown in Table 2.
Results obtained could be summarized as follows:
1 - Irrespective of methionine supplementation, chicks fed high protein
diets (23%), during starting period ( 1-28 days) resulted a significant (P<0.01) increase in each of the final body weight, body weight gain and feed intake, which reflect on improving of the feed conversion when compared to chicks fed low protein diets (21 %). On the other hand, protein efficiency ratio and percentage of viability were not affected significantly due to increase the CP level in the diet. However, feed cost of kilogram body weight gain increased significantly (P<0.01) only as protein level increased during starting period.
2- Irrespective of CP level in the starter diet, supplementation of 0.1 % of methionine to the diets, during starting period caused a significant (P<0.01) increase in each of final body weight, body weight gain and feed intake. Moreover, protein efficiency ratio improved significantly (P<0.01) only also due to methionine supplementation, during starting period, while feed conversion ratio, viability percentage and feed cost of 1 Kg body weight were not affected significantly due to treatment, during experimental periods.
3-Chicks fed high protein diets (21 0/0), during growing period (29-49 days) resulted a significant (P<0.01) increase in each of the final body weight at 49 days and body weight gain during that period when compared with chicks fed medium (19%) or low (17%) protein in the diets. In addition, the high level of CP in diet caused a significant (P<0.01) increase in each of feed conversion, protein efficiency ratio and viability (%). In the same time, feed cost of 1 Kg body weight was not affected due to high level of CP.
4- Irrespective of CP level in the finishing diet, supplementation of 0.1 % of mothionine to the diet, during the growing period improved significantly (P<0.01) each of final body weight, live body weight gain and increased significantly (P<0.01) the feed intake. In addition, the feed conversion feed cost for 1 kg live body decreased significantly (P<0.01) due to methionine supplementation at growing diets.
5- Increased CP level in diet either starter or finishing caused a significant increase in carcass weight and a significant (P<0.01(decrease (P<0.01) in each of liver and abdominal fat. However, methionine supplementation either in starter or finishing diets caused a significant (p<0.01) increase in each of carcass, blucked and giblet weights.
6- Increased CP level or supplement of 0.1 % methionine in starter or finishing diets increased significantly (P<0.0l) the protein content and decreased each of fat and ash contents of the liver.
CONCLUSION
It is concluded that chicks fed high level of protein in starter period (23%) and in growing period (21%) with 0.1 methionine supplement were
superior in the final body weight, live body weight gain and carcass traits.
Therefore, the CP level in the starter and growing diets should not decrease on 23 and 21%, respectively, with 0.1% methionine supplement to obtain the most gain and viability with no more economical cost.
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| Publication year |
1999
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| Pages |
PP. 169
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| Availability location |
مكتبة معهد بحوث الانتاج الحيوانى-شارع نادى الصيد- الدقى- الجيزة
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| Availability number |
643
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| Organization Name |
Animal Production Research Institute (APRI)
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| Country |
Egypt
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| Author(s) from ARC |
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| Agris Categories |
Animal feeding
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AGROVOC
TERMS |
Body weight.
Broiler chickens.
Feed conversion efficiency.
Feed intake.
Methionine.
Nutritional requirements.
Proteins.
Sulphur amino acids.
Tropical climate.
Viability.
Weight gain.
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| Publication Type |
PhD Thesis
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