Redução do nível de proteína bruta da ração para frangos de corte mantidos em diferentes ambientes térmicos

• Ano de defesa: 2008
• Autor(a) principal: Oliveira, Will Pereira de
• Orientador(a): Donzele, Rita Flávia Miranda de Oliveira
• Banca de defesa: Albino, Luiz Fernando Teixeira , Silva, Francisco Carlos de Oliveira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Zootecnia
• Departamento: Genética e Melhoramento de Animais Domésticos; Nutrição e Alimentação Animal; Pastagens e Forragicul
• País: BR
• Palavras-chave em Português: Fatores climáticos; Aminoácidos; Proteína bruta
• Palavras-chave em Inglês: Environmental factors; Amino acids; Crude protein
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL::AVALIACAO DE ALIMENTOS PARA ANIMAIS
• Link de acesso: http://locus.ufv.br/handle/123456789/5574

A total of 560 broilers were used in two experiments to evaluate the effects of dietary crude protein (CP) level reduction with supplementation of industrial amino acids on the performance and carcass yield and noble cuts of broilers in the growth period (22 to 42 days of age), maintained in different environmental temperatures. In the first experiment were used 280 Cobb broilers from 22 to 42 days of age, maintained under heat stress (32,2°C) and the black globehumidity index (BGHI) calculated for the period was 83.1 ± 0.9. In the second experiment were used 280 Cobb broilers from 22 to 42 days of age, maintained under thermoneutral conditions (22,5°C) and the black globe- humidity index calculated for the period was 69.6 ± 0.9. In both experiments a completely randomized experimental design, with five treatments (21.6; 20.6; 19.6; 18.6 and 17.6 % CP), eight repetitions and seven birds per experimental unit were used. In the first experiment, there was no effect (P>0.05) of dietary CP levels reduction on weight gain, feed intake and feed conversion of the birds. The reduction of dietary CP levels influenced the absolute weights of carcass (P<0.02) and breast (P<0.04), being the level of 20.6% the one that proportioned higher carcass and breast weights of the broilers in relation to that of 21.6% of CP. However, there was no effect (P>0.05) of the levels of CP on absolute values of thigh and drumstick and also on breast, thigh and drumstick yields. In the second experiment, there was no effect (P>0.05) of the reduction of the levels of CP on weight gain and feed intake. The feed conversion was influenced (P<0.01) by the reduction of the CP levels, being the birds fed diet with the 21.6% level of CP showed a better result. The reduction of the levels of CP did not influence (P>0.05) the absolute carcass weight and absolute and relative weights of breast, thigh and drumstick. It was concluded that the dietary CP level, formulated using the ideal protein concept, can be reduced from 21.6 to 17.6% without affecting negatively the performance and noble cuts yield of broilers under heat stress. Under thermoneutral conditions, the reduction of the level of dietary CP, formulated using the ideal protein concept, from 21.6 to 17.6% affected negatively the feed conversion of broilers, but did not influence the others performance and carcass characteristics.