2.7. Carcass characteristics
At 13 weeks of age, the chickens (108 males and 108 females) were electrically stunned and killed by manual exsanguination. The feet, heads and intestines were manually removed. The carcasses were weighed to determine the slaughter yield before being cut according to a standardized procedure (Uijttenboogaart and Gerrits, 1982) to determine the weight of breast (without skin), upper legs(thigh), lower legs (tibia and foot), and wings. These measurements were expressed as a percentage of the carcass weight.