Comparison of reproduction and carcass traits in light type of ducks of four conservative flocks over eight generations
Abstract. Ducks of four conservative flocks: Khaki Campbell (Kh1), Orpington (01), crossbreds of those two breeds (Kh0) and Miniducks (K2) being kept without selection over 8 generations were used for analysis. The mean values of reproductive and carcass traits were determined and illustrated by linear regression equations. In the first year of study a significant differentiation was noted among flocks in: number of eggs, from 101 (K2) to 156 (Kh1); egg weight, from 70 (K2) to 75 g (Kh0) and hatchability from fertilized eggs, from 62 (Kh0) to 72% (K2). Upward time trends in egg weight and hatchability from fertilized eggs were noted in all flocks of birds, whereas in egg number in Kh1, 01 and K2 flock; and in egg fertilization in Kh1 and Kh0 flocks. In the second year a lower egg number and egg weight were found, as well as lower egg fertilization and hatchability. Differentiation in meatiness mean values between flocks was found over 8 generations of both sexes at 7 weeks of age in body weight and in breast and leg muscles yield in the carcass. Upward time trends in leg muscle yield and skin with subcutaneous fat content in the carcass were noted in all flocks of ducks of both sexes while in body weight at 7 weeks of age in the females of Kh1 and K2 flocks. Contrary, downward time trends in the body weight at 3. week of age and in breast muscle yield at 7. week of age were found in birds of both sexes and all conservative flocks.