1. Digestible tryptophan:lysine ratio for laying hens
- Author
-
Sarah Gomes Pinheiro, Ricardo Romão Guerra, Eduardo Terra Nogueira, José Humberto Vilar da Silva, Fernando Guilherme Perazzo Costa, Maria Angélica Miglino, Carlos Bôa-Viagem Rabello, and Matheus Ramalho de Lima
- Subjects
histological effects ,business.industry ,Lysine ,Soybean meal ,Tryptophan ,egg production ,Biology ,Poultry farming ,Animal Science and Zoology ,Food science ,lcsh:Animal culture ,Corn gluten meal ,business ,Corn starch ,Completely randomized design ,INDÚSTRIA AGRÍCOLA ,poultry industry ,lcsh:SF1-1100 - Abstract
The objective of this study was to evaluate the requirement of digestible tryptophan for white laying hens in the production stage fed diets of different digestible tryptophan:digestible lysine ratios, as well as animal performance and histological alterations in their reproductive and digestive systems. A total of 280 white laying hens at 29 weeks of age were distributed in a completely randomized design with five treatments and seven replications with eight birds in each. The treatments consisted of a base feed, formulated with corn, soybean meal and corn gluten meal, and supplemented with the synthetic amino acids L-lysine, DL-methionine, L-threonine, L-isoleucine, L-arginine, and L-valine, so as to meet the nutritional requirements for laying hens, except for digestible tryptophan. The basal diet was supplemented with 0.00; 0.017; 0.035; 0.052; and 0.069 g/kg of L-tryptophan in substitution for corn starch with the objective of reaching the levels of 0.151; 0.167; 0.183; 0.199; and 0.215 g/kg of digestible tryptophan in the feed. For the ratio between digestible amino acids and lysine, the recommendation of Brazilian Tables for Poultry and Swine was followed, except for the digestible tryptophan:digestible lysine ratios, which were 19, 21, 23, 25 and 27 for each treatment. The variation in the digestible tryptophan:digestible lysine ratio promoted changes in performance and in the histological characteristics, improving the results. The digestible tryptophan:digestible lysine ratio of 24.5% in the feed of white laying hens in production stage promotes better animal performance and histological results.
- Published
- 2012