Effects of stocking density on growth performance, carcass traits, and foot pad lesions of White Pekin ducks.

Two experiments were conducted to study the effects of stocking density on growth performance, carcass yield, and foot pad lesions of White Pekin ducks from hatch to 14 d of age (experiment 1) and from 14 to 42 d of age (experiment 2), respectively. All ducks were reared in raised plastic wire-floor pens with a pen size of 30 m(2), and males and females were mixed at a ratio of 1:1 in each pen of both experiments. In experiment 1, a total of 10,200 ducks that were 1 d old were allotted to 20 pens according to the stocking densities of 13, 15, 17, 19, and 21 birds/m(2) (or 8.4, 9.7, 10.9, 11.9, and 13.0 kg of actually achieved BW/m(2)), respectively, with 4 replicates per treatment. In experiment 2, a total of 3,150 ducks that were 14 d old were allotted to 15 pens according to the stocking densities of 5, 6, 7, 8, and 9 birds/m(2) (or 17.0, 20.3, 23.6, 26.9, and 29.9 kg of actually achieved BW/m(2)), respectively, with 3 replicates per treatment. The stocking density had significant effects on final BW and weight gain of starter and growing ducks (P < 0.05), but not on feed/gain and mortality in both periods (P > 0.05). The final BW and weight gain of starter and growing ducks all decreased with increasing density (P < 0.05). Final BW and weight gain of starter ducks were reduced significantly as stocking density increased from 17 to 21 birds/m(2) (P < 0.05). In addition, final BW and weight gain of growing ducks decreased significantly when stocking density was 9 birds/m(2) (P < 0.05). On the other hand, increasing stocking density did not markedly influence the carcass, breast meat, leg meat, abdominal fat, and foot pad lesions of growing ducks (P > 0.05).