Meat quality analyses
To determine the cooking loss, the breast from each duck was cut into pieces about 3 cm thick, boiled individually in polyethylene bags immersed in 80°C water bath for 30 min and cooled at room temperature for 30 min. The cooking loss was calculated from the weights of uncooked and cooked meats. The water holding capacity (WHC) was estimated according to filter paper pressed method (Grau and Hamm, 1953).