Rendimento de carcaça e composição de peitos de frangos de corte de duas linhagens comerciais mantidos em diferentes períodos de exposição ao calor

Abstract

High temperatures are still a challenge in its production, because their performance and welfare may be affected. In this way the effects of different heat exposure times carcass yield, cuts and edible viscera and chemical composition of broiler breast meat of Cobb 500 Slow® lineage and Hubbard Flex® were evaluated. To this were housed 560 chickens from each strain in 32 boxes and that from day 14 were subjected to 1, 2 or 3 hours daily to heat stress. Carcass yield, the boneless breast, thigh and drumstick bone, wings, feet, liver, gizzard and heart were evaluated in six poultry of each strain in each thermal environment. Boneless breast samples were obtained to analyze dry matter, ether extract, crude protein and mineral matter. The cyclic heat stress for up to three hours daily did not influence the carcass yield, boneless breast, thigh and drumstick, wing, heart, gizzard, liver and the chemical composition of the breast. The Cobb 500 Slow® strain showed higher breast yield but higher percentage of her ether extract and lower yield of thigh and drumstick, wing, feet and liver compared to Hubbard Flex® that presented breast with a higher percentage of protein and mineral matter. Chickens of Cobb 500 Slow and Hubbard Flex can be created under high cyclic temperature for up to three hours from the 14th to the 41st day. The Cobb is best designed to chest production, and Hubbard lineage is best designed for the whole chicken commerce.