Estimates of stocking density of female geese in different growth stages

A high stocking density can have a negative effect on growth performance, walking ability, and antioxidant capacity of poultry. In geese production, multiple-phase feeding strategy is generally adopted when considering the long raise period for geese. However, the corresponding density parameters are lacking in different growth stages. The aim of this study was to estimate the optimum stocking density of geese from 14 to 28 d of age and 28 to 49 d of age and investigate the effects of stocking density on antioxidant capacity of geese from 28 to 49 d of age. Two trials were used in this study. In experiment 1, a total of 432, 14 d of age female White Sichuan geese were allocated randomly to 6 treatments with 6 replicate pens per treatment according to the stocking densities of 4.67, 6.00, 7.33, 8.67, 10.00, and 11.33 birds/m2, respectively. In experiment 2, a total of 324, 28 d of age female White Sichuan geese were allocated randomly to 6 treatments with 6 replicate pens per treatment according to the stocking densities of 2.50, 3.75, 5.00, 6.25, 7.50, and 8.75 birds/m2, respectively. With the stocking density increasing, body weight and weight gain decreased linearly or quadratically in experiment 1 (P < 0.05), feed intake decreased quadratically (P < 0.05), and feed/gain ratio (F/G) increased (P < 0.05). In experiment 2, as the stocking density increased, the body weight and weight gain decreased linearly (P < 0.05), while F/G increased linearly (P < 0.05). In addition, the increasing stocking density resulted in that the serum total antioxidant capacity (T-AOC) level and activity of superoxide dismutase (SOD) both decreased linearly (P < 0.05). According to linear broken-line regression, the upper critical stocking density of geese from 14 to 28 d of age for weight gain was 6.15 birds/m2 (or 8.34 kg of actually achieved BW/m2) and it was 4.83 birds/m2 (or 11.4 kg of actually achieved BW/m2) for F/G of geese from 28 to 49 d of age.