Restrição alimentar e uso de alimentos alternativos na dieta de frangos de corte de crescimento lento

Abstract

Four experiments were carried out to evaluate the effects of a restrictive diet and the inclusion of alternative food in the diet of slow growing broilers, ISA Label JA57 (naked neck) lineage, on performance parameters, yield and carcass characteristicsIn Experiment I, a digestibility trial was carried out to determine the energy value of alfalfa and coast cross hay, using 108 male broilers, distributed into a completely randomized experimental design, with three treatments, six replicates and six birds per experimental unit. The test-diets were composed of 70% of the reference diet (based on corn and soybean meal) and 30% of the food to be tested. The alfalfa and coast cross hays showed 1,173 kcal and 1,316 kcal of AME / kg, 1,143 kcal and 1,297 kcal of AME / kg, respectively, in the dry matter. In Experiment II, 272 broiler chickens, males, were used from 21 to 70 days of age and distributed into a completely randomized experimental design with four treatments and four replicates and 17 birds per experimental unit. The treatments consisted of free concentrated feeding (intake control), dietary restriction (80% of the intake control) and dietary restriction with the inclusion of ground alfalfa hay (80% of the intake control + 20% of alfalfa hay) and coast cross (80% of the intake control + 20% of coast cross hay). The weight gain was lower (P<0.05) in animals submitted to dietary restriction and restriction with the inclusion of hay, but feed conversion was better (P<0.05) for animals that had restricted feeding. The chickens subjected to dietary restriction with the inclusion of the hays had higher (P<0.05) relative weight of the gizzard, small intestine and large intestine, villus height and crypt depth in the duodenum and number of goblet cells in the ileum. The inclusion of alfalfa and coast cross hay kept the coloring of the breast meat, even with the dietary restriction. The birds with restricted food had lower (P<0.05), small intestine length, villus height in the duodenum and crypt depth in the jejunum, however, the.