This experiment aimed to investigate effects of the different dietary levels of vitamin E (VE) on the growth performance, immunity and antioxidant capacity of goslings. A total of 240 1-day-old, male Jiangnan white goslings were selected and randomly divided into 6 groups. Each treatment included five replicates. The basal diet was supplemented with 6 concentrations of VE (0, 12, 24, 36, 48 and 60 mg DL-α-tocopherol acetate/kg). The results were as follows: (1) The α-tocopherol content in the serum and liver of goslings increased linearly as supplemental VE increased in diet (p < 0.05). (2) The body weight (BW) and average daily gain (ADG) increased quadratically with increasing dietary VE supplementation (p < 0.05). Dietary VE supplementation could significantly reduce the feed/gain ratio (F/G) (p < 0.05). (3) Dietary supplementation with VE could significantly improve the contents of immunoglobulin A (IgA) and immunoglobulin G (IgG) in the serum of the goslings (p < 0.05). The content of interferon-γ (IFN-γ) in the serum was significantly reduced with VE supplementation (p < 0.05). (4) Dietary supplementation with VE could significantly improve serum and liver catalase (CAT), superoxide dismutase (SOD) activities and liver total antioxidant capacity (T-AOC) (p < 0.05); Serum and liver MDA contents were significantly reduced with VE supplementation (p < 0.05). In summary, dietary supplementation with VE could improve growth performance, immunity and antioxidant capacity. Based on broken-line regression analysis, the dietary VE supplementation level for ADG was 12.51 mg/kg, but higher supplementation level should be considered to improve immunity and antioxidant capacity.
Effects of dietary vitamin E on growth performance, body composition, antioxidant capacity, and some immune responses in Caspian trout (Salmo caspius)
