Diferentes fontes de proteína na dieta pré-inicial de frangos de corte Different sources of protein in the diet of newly hatched chicks

Abstract

Objetivou-se, com este estudo, determinar o valor de energia metabolizável aparente corrigida (EMAn) de ingredientes protéicos alternativos, para frangos de corte na fase pré-inicial, e avaliar os efeitos da utilização desses ingredientes na primeira semana de vida de frangos sobre o desempenho e o desenvolvimento do trato gastrintestinal (TGI). No ensaio de metabolismo, 288 aves (4 a 7 dias de idade) foram distribuídas em seis tratamentos (uma dieta-referência e cinco dietas com inclusão dos ingredientes-teste: isolado protéico de soja [IS], ovo em pó [OP], plasma sangüíneo [PS], farelo de glúten de milho [GM] e levedura seca [LS]) e quatro repetições de 12 aves. Na avaliação do desempenho e do TGI, 624 aves foram alojadas em baterias com seis tratamentos e quatro repetições de 26 aves. Os tratamentos consistiram em: 1 - dieta de milho e farelo de soja, 2 - dieta de milho e farelo de soja + IS, 3 - dieta de milho e farelo de soja + OP, 4 - dieta de milho e farelo de soja + PS, 5 - dieta de milho e farelo de soja + GM e 6 - dieta de milho e farelo de soja + LS. As aves foram submetidas aos tratamentos de 1 a 7 dias de idade. Aos 1, 4 e 7 dias de idade, as aves foram abatidas para mensuração dos órgãos do TGI. A EMAn dos ingredientes foi de 2.110, 5.095, 3.831, 3.374 e 2.037 kcal/kg (na matéria natural) para IS, OP, PS, GM e LS, respectivamente. De maneira geral, o desempenho das aves de 1 a 7 dias de idade foi afetado pelos diferentes tratamentos, mas esse efeito não persistiu até os 21 dias. As diferentes fontes de proteína afetaram o desenvolvimento do TGI, mas esses efeitos não explicam o desempenho das aves.The purpose of this study was to determine the N-corrected apparent metabolizable energy (EMAn) of alternative protein ingredients, for newly hatched chicks, and to evaluate the effects of the utilization of these ingredients in the first week broiler feed, on the performance and gastrointestinal tract (TGI) development. In the metabolism trial, 288 male chicks from 4 to 7 days were allotted to a completely randomized design with six treatments (a reference diet and five diets with inclusion of the test ingredients) and four replicates of 12 birds. The ingredients evaluated were: isolated soy protein (IS), dried whole eggs (OP), blood plasma (PS), corn gluten meal (GM) and dried sugar cane yeast (LS). To evaluate the performance and TGI, 624 birds were allocated in brooder batteries with six treatments and four replicates of 26 birds. The treatments were: 1 - corn and soybean meal diet, 2 - corn and soybean meal diet + IS, 3 - corn and soybean meal diet + OP, 4 - corn and soybean meal diet + PS, 5 - corn and soybean meal diet + GM and 6 - corn and soybean meal diet + LS. The birds received the treatments only from 1 to 7 days. Birds were sampled at 1, 4 and 7 days of age in order to evaluate the TGI organs. The EMAn of the ingredients determined for chicks in the first week were 2,110; 5,095; 3,831; 3,374 and 2,037 kcal/kg (as-fed basis) for IS, OP, PS, GM and LS, respectively. In general, the performance of the birds from 1 to 7 days was affected by the different treatments, but this effect was not maintained up to 21 days. The different protein sources affected the TGI development, but these effects did not explain broiler performance.

Keywords

• desempenho
• dieta pré-inicial
• energia metabolizável
• frangos de corte
• proteína
• trato gastrintestinal
• broilers
• gastrointestinal tract
• metabolizable energy
• newly hatched chick diets
• performance
• protein