Dietary crude protein reduction on growth and carcass performance of 22 to 42-day-old broilers reared under different temperatures

Revista Brasileira de Zootecnia

Oliveira, Will Pereira de¹  Oliveira Neto, Adhemar Rodrigues de³  Campos, Paulo Henrique Reis Furtado¹  Maia, Ana Paula de Assis¹  Donzele, Juarez Lopes¹  Oliveira, Rita Flávia Miranda de¹  Gasparino, Eliane²  Gomes, Paulo Cezar¹ 

[1] Universidade Federal de Viçosa, Viçosa, Brazil;Universidade Estadual de Maringá, Maringá, Brazil;Evonik Degussa do Brasil, São Paulo, Brazil

关键词: breast yield;    heat stress;    temperature;    thermoneutral temperature    Introduction Performance and carcass yield of broilers are severely and negatively affected by high temperatures;    which are common in tropical countries (Rostagno;    1995;    Cheng et al;   

DOI  :  10.1590/S1516-35982013000800010

学科分类：兽医学

来源: Universidade Federal de Vicosa

【 摘 要 】

This study was conducted to verify the effects of dietary crude protein reduction on growth and carcass performance of 22-42-day-old broilers reared under different temperatures. Treatments were set up in a five by two factorial arrangement, with five crude protein levels (220, 210, 200, 190 and 184 g/kg) and two temperatures (21.6 and 32.2 ºC). Diets were isocaloric and essential amino acid-to-lysine ratio was maintained constant in all treatments. There was no interaction between crude protein reduction and environmental temperature for any of the parameters evaluated. Crude protein had no influence on feed intake. Nevertheless, weight gain and feed conversion ratio were linearly influenced by crude protein reduction. Worse performance was also observed in birds exposed to heat stress as compared with birds kept under thermoneutral temperature. There was no effect of crude protein reduction on breast and legs. Birds kept under heat stress had lower breast yield and higher leg yield as compared with broilers reared at 21.6 ºC. Any crude protein reduction in the range of 220 to 184 g/kg for 22 to 42-day-old broilers has a negative effect on their performance. Heat stress worsens broiler performance and breast yield.

【 授权许可】

CC BY-NC