Growth and carcass characteristics of different crosses of broiler chickens reared under an alternative system

Abstract

This study aimed to assess the effect of different breeds and crosses of broiler chickens and sex on growth, carcass characteristics, and tissue composition. The experimental design was a completely randomized design in a 6 × 2 factorial scheme, with six genotypes (New Hampshire – NHS, Jersey Black Giant – JBG, Rodhe Island Red – RIR, Indigenous Giant – IG, and the hybrids IG × NHS and IG × JBG) and two sexes (male and female). Each treatment was composed of five replications with three broiler chickens, totaling 180 broiler chickens. Zootechnical performance and growth were assessed through the Gompertz equation parameters. After slaughtering at 105 days, the characteristics of carcass and main cuts were determined by means of weight, yield, and proportion of tissue constituents (meat, bone, and skin). Regarding the Gompertz equation parameters, the genotype NHS presented a higher growth potential. Males presented higher live weight and carcass weights, except for IG. No difference was observed between genotypes and sexes (P > 0.05) for carcass yield. The genotype JBG presented the highest average for breast yield (24.4%). Males presented the highest average for leg yield (30.5%). The genotype IG presented the highest value of breast meat yield (71.2%), being similar to the genotypes from the crosses IG × NHS, and IG × JBG (68.9 and 68.3%, respectively). For meat to breastbone ratio, the genotype IG presented the highest value (3.4) and, considering the sex, females presented a higher average (3.2) for this characteristic. Regarding the proportion of leg meat, an effect was observed for genotype and sex (P < 0.05) with the highest values observed for the hybrid IG × JBG and females (66.3 and 66.0%, respectively). For meat to leg bone ratio, the genotypes NHS, JBG, RIR, and IG × NHS presented the highest values (2.6, 2.7, 2.6, and 2.6, respectively), with females presenting the highest value (P < 0.05) (2.7). The genotypes IG, IG × NHS and IG × JBG presented the best growth and carcass characteristics, being recommended to be reared under an alternative system. Females presented the highest breast yield and, proportionally, the highest amount of leg meat, which are important attributes in a chicken meat production system.