Response of broiler chicks to L-Tryptophan supplementations in low protein corn –soybean meal diets
Abstract: An experiment was conducted using two strains of broiler chicks (Hubbard and Rose308) and six dietary treatments in a 2x6 factorial design to investigate the response of broiler chicks to L-Tryptophan (Try) supplementations in low protein corn-soybean
meal diets. One hundred and forty four, unsexed one-day old chicks, from each strain were divided equally (three replicates of eight chicks each) and assigned into the six dietary treatments. Five supplementary L-Try (0.0, 0.1, 0.2, 0.3, and 0.4% of the diet) were added to low protein basal diets (18, 16 and 15% CP during 1-14, 15-24 and 25-40 days of age, respectively) and fortified with adequate amino acids of Met, Lys and Thr. In addition to the control diet contained recommended crude protein (23, 20 and 18% CP during 1-14, 15-24 and 25-40 days of age, respectively) and formulated based on ideal amino acid profile recommended for broiler chicks. Supplementing low protein diets with Try had no significant effects on weight gain during 1-14, or 15-24 days of age, but significantly improved that parameter during 25-40 days of age. Feed conversion ratio was not significantly affected at any given period. The best weight gain and feed conversion ratio were obtained with 0.1% Try supplementation (0.26% digestible Try) during 25-40 days of age. Tryptophan supplementation had no significant effect on dressing weight, abdominal fat or breast yield. Regarding strain effect, Ross strain had significantly better weight gain, feed conversion ratio, breast yield and economical efficiency than Hubbard strain. No significant differences were found in weight gain, feed conversion ratio or breast meat between low protein and conventional protein diets. The interactions between dietary Try supplementation and strain were not significant at any variable measured. It is concluded that using low-protein diets (18, 16 and 15% during 1-14, 15-24 and 25-40 days of age, respectively) supplemented with required amount of Met, Lys, Thr and Try for broiler chicks gave performance (body weight gain, feed conversion ratio and breast yield) similar but economically better than that resulted from conventional protein diets formulated based on ideal amino acids. Furthermore, using low-protein supplemented-amino acid diets had a positive impact on the environment.
Keywords: Tryptophan, low-protein diets, ideal amino acid profile, broiler strains performance, breast yield.
Publication year 2009
Pages 1000-1012
Availability location معهد بحوث الانتاج الحيوانى- شارع نادى الصيد- الدقى - الجيزة
Availability number
Organization Name
City طابا
serial title 5th International Poultry Conference
Author(s) from ARC
Agris Categories Animal feeding
AGROVOC
TERMS		 Broiler chickens. Maize. Performance testing. Protein restricted diets. Soybeans. Tryptophan.
Proposed Agrovoc breast yield;ideal amino acid;
Publication Type Conference/Workshop
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