Different threonine: lysine relations in chicks cutting diets supplemented with glycine: enzymatic activity and performance / Diferentes relações treonina: lisina em dietas para pintos de corte, suplementadas com glicina: desempenho e atividade enzimática

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Two experiments were conducted, one for performance and another for metabolism, with objectives of evaluating the effect of different digestible threonine: digestible lysine relations, supplemented or not with glycine on the performance, the threonine aldolase, threonine dehydrogenase and threonine dehydratase enzyme activity and the uric acid excretion of chicks cutting in the period of 8 to 21 days of age. For both experiments, 560 chicks cutting were used, all male, Coob lineage, distributed in completely randomized design, in a 3 x 2 factorial arrangement, being the digestible threonine: digestible lysine relations (55; 65 e 75 %), supplemented or not with glycine. An additional treatment containing meat flour was used with a 65% digestible threonine: digestible lysine relation. All treatments had eight repetitions and 10 birds per experimental unit, being lodged e metabolic batteries. A full collection of excrete proceeded during the experimental phase. For the analysis of the threonine aldolase, threonine dehydrogenase and threonine dehydratase enzyme activities, two birds per experimental unit were slaughtered and the liver and the pancreas were removed. The glycine supplementation did not influence (P>0,05) the nitrogen retention by the birds, however, it was essential to improve (P<0,05) the chicks cutting performance. The activity of the three examined enzymes in the liver and pancreas was influenced by the threonine levels of the diet. The birds fed with the diet that contained the meat flour had a more intense threonine aldolase activity in the liver and in the pancreas; the threonine dehydrogenase and the threonine dehydratase activity was smaller in the liver and higher in the pancreas in comparison to the birds fed with vegetable diet. The threonine levels of the diet and the supplementation of glycine did not influence the uric acid excretion from the birds. The glycine supplementation reduced the evaluated enzyme activity in the liver and in the pâncreas, providing a higher threonine amount for the protein deposition. Although, the threonine catabolism has been high in birds fed with the digestible threonine relation: digestible lisina of 55%, the feed conversion was not affected by the levels of threonine, therefore, the 55% threonine: lysine relation (0,631% digestible threonine), supplemented with glycine is enough to attend the demands of chicks cutting in the period of 08 to 21 days of age.

ASSUNTO(S)

nutricao e alimentacao animal nutrição animal threonine poultry treonona animal nutrition glicina fedds and feeding alimentação e rações glycine frango de corte

ACESSO AO ARTIGO

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