Development of dual-purpose cross for meat and egg production I. Growth performance and carcass composition of the crossbred chickens in comparison to the parent lines

The aim of the study was to develop a dual-purpose cross suitable for rearing in alternative systems and to examine its growth performance and carcass composition in comparison to the parent lines. The experiment was carried out in the experimental poultry farm in the Institute of Animal Science - Kostinbrod. The cross was developed using females of a layer type line L and cocks from line BB. The latter was based on Bresse Gauloise that is also dual purpose but mainly used for meat. The chickens from the lines and the cross were reared in mixed-sex groups on deep litter, at stocking density of 25 birds/m², and fed with standard broiler feed until the age of 9 weeks. Then the males were separated and sent to slaughter while the females were left for layers. Crossing hens from layer type line L with BB cocks resulted in dual-purpose chickens with a live weight and feed efficiency that were better in comparison to L line, but lower when compared to the BB line. These parameters were however, lower than the typically observed in this type of poultry. Nevertheless, the chickens displayed good carcass composition and deposited low content of abdominal fat, thus revealing good potential to be successfully realized in market.