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.
broilers; gastrointestinal tract; metabolizable energy; newly hatched chick diets; performance; protein
