1. Nutritional requirement of digestible tryptophan for white-egg layers of 60 to 76 weeks of age.
- Author
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Cardoso, Anilma Sampaio, Costa, Fernando Guilherme Perazzo, Vilar da Silva, José Humberto, Saraiva, Edilson Paes, Nogueira, Eduardo Terra, Santos, Clariana Silva, Ramalho de Lima, Matheus, and Vieira, Danilo Vargas Gonçalves
- Subjects
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AGRICULTURAL egg production , *NUTRITIONAL requirements , *TRYPTOPHAN , *POULTRY , *HENS - Abstract
The objective of this study was to determine the nutritional requirement of digestible Trp for white egg layers in the period from 60 to 76 wk of age. A total of 180 Dekalb White layers with an average weight of 1,345 kg were distributed in a completely randomized design with 5 increasing levels of digestible Trp (0.167, 0.175, 0.183, 0.191, and 0.199%), 6 replicates, and 6 birds per experimental unit. The diets of the treatments contained 0.759% of digestible Lys, which was obtained using the prediction equation of the Brazilian Tables for Poultry and Swine, and each treatment consisted of a digestible Trp-to-Lys ratio of 22, 23, 24, 25, or 26%. The digestible Trp levels in the diet had a quadratic effect on egg production, egg mass, and conversion per mass and per dozen eggs, and a linear effect on egg weight. In conclusion, a diet with 0.192% digestible Trp, in a 25.33% ratio with digestible Lys or 212 mg/bird per day, can be recommended for white egg layers of 60 to 76 wk of age. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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