Levels of lysine for gilts with high genetic potential for lean meat deposition from 30 to 60 kg, mantaining constant the relation of lysine and methionine+cystine, threonine, tryptophan, isoleucine and valine

Revista Brasileira de Zootecnia

Donzele, Juarez Lopes²  Oliveira, Rita Flávia Miranda de²  Pereira, Mariana Aragão²  Conhalato, Giane da Silva¹  Fontes, Dalton de Oliveira³ 

[1] UFV;UFMG

关键词: carcass;    genotype;    growing phase;    ideal protein;    requirement     IntroduçãoLisina é considerado o primeiro aminoácido limitante em dietas de suínos à base de milho e soja;    entretanto;    estimativa do requerimento deste aminoácido;    para suínos nas diferentes fases de crescimento;    tem apresentado grande variação;   

DOI  :  10.1590/S1516-35982000000300020

学科分类：兽医学

来源: Universidade Federal de Vicosa

【 摘 要 】

- Forty crossbred gilts (Hampshire, Belgium Landrace, Pietran) with initial average weight of 30.1±1.25 kg and high genetic potential for lean meat deposition were used to evaluate different lysine levels. A randomized block experimental design, with four treatments, five replications and two animal per experimental unit, was used. The treatments corresponded to the basal diet with 17.5% crude protein, supplemented with L-lysine-HCl, resulting in diets with 1.00, 1.10, 1.20 and 1.30% of lysine. The diets were supplemented with increasing levels of threonine, methionine, isoleucine, valine and tryptophan, resulting in diets where the amino acids:lysine ratio was constant in 67, 52, 60, 68 and 19%, respectively, based on the true digestibility. There was no effect of treatments on feed intake, daily weight gain and blood serum urea concentration of animals, however, the animals seems to reach their maximum genetic potential for weight gain at lysine level of 1.10% (0.329%/Mcal de DE), corresponding to a lysine intake of 22 g/day. There was linear effect on daily lysine intake, that increased, and on feed:gain ratio that reduced with increasing dietary lysine level. The level of 1.30% (0.389%/Mcal of DE) or 1.19% (0.356%/Mcal of DE), corresponding to a total and digestible lysine intake of 24 and 22.1 g/day, respectively, showed the best results of feed:gain ratio of gilts from 30 to 60 kg, when the ideal protein concept was used in the diet formulation.

【 授权许可】

CC BY-NC