Performance and carcass characteristics of broiler chickens with different growth potential and submitted to heat stress

• Autor(a) principal: Rosa,PS
• Data de Publicação: 2007
• Outros Autores: Faria Filho,DE, Dahlke,F, Vieira,BS, Macari,M, Furlan,RL
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Poultry Science (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2007000300007
• topic: Allometric coefficient; carcass yield; genetic improvement; heat stress

In order to evaluate the effects of broiler genotype and of heat exposure on performance, carcass characteristics, and protein and fat accretion, six hundred one-day-old male broilers were randomly assigned in a 2 x 3 factorial arrangement, according to the following factors: genetic group (selected and non-selected broilers) and pair-feeding scheme (Ad32 - reared under heat stress and fed ad libitum; Ad23 - reared at thermoneutrality and fed ad libitum; Pf23 - reared at thermoneutrality and pair fed with Ad32), with a total of six treatments with four replicates of 25 birds each. Independent of pair-feeding scheme, selected broilers showed better feed conversion, higher carcass yield, and lower abdominal fat deposition rate. However, as compared to non-selected broilers, they reduced more intensively feed intake when heat exposed, which promoted significant breast-yield decrease, and more pronounced changes on carcass chemical composition. These findings allows concluding that, in both genetic groups, both environmental temperature and feed-intake restriction influence abdominal fat deposition rate and other carcass characteristics; however, the impact of heat exposure on broiler performance is more noticeable on the selected line.