Effect of genotype and sex on carcass characteristics of chickens raised in extensive system

The aim of this work was to examine the possibility of using different poultry breeds for meat production in extensive systems, concerning their slaughter traits. Total of 200 birds of two genotypes were used in this trial: fastgrowing hybrid Ross 308 and pure breed White Rock. Chicks were raised indoors until the age of 4 weeks and subsequently they were enabled to access the range. The trial lasted for 13 weeks. At the end of the trial, 10 male and 10 female chicks per breed were sacrificed for the evaluation of slaughter traits – dressing percentage, yield and share of carcass parts. It was established that both genotype and sex significantly affected carcass traits while genotype affected production traits. Chickens of the Ross 308 hybrid had higher body weights, better feed conversion ratio and higher mortality rate. Chickens of the Ross 308 hybrid had dressing percentage compared to the White Rock breed, while the male chickens had higher dressing percentage compared to the female ones. Chickens of the Ross 308 hybrid had a significantly larger weight and share of breast meat, whereas those of the White Rock breed had a larger share of drumsticks and thighs. A significant influence of the genotype was determined on the amount of abdominal fat in the carcass. Chickens of the White Rock breed had a significantly lower fat content compared to the Ross 308 hybrid, which essentially makes them the genotype which is more suitable for the extensive fattening longer than 10 weeks.