Abstract
The application effects of phytosterols on poultry production have been reported. However, due to the mixed compositions, it is difficult to explain their action mode and physiological functions. β-sitosterol, the most abundant phytosterol, is naturally widespread in plant products. Information, however, is scarce in terms of effects of β-sitosterol on broilers. This research therefore investigated effects of dietary β-sitosterol with different levels on immunity and antioxidant capacity in broilers. Two hundred and forty one-day-old chicks were randomly allocated into five treatments of six replicates. Chickens in the five groups were fed a basal diet supplemented with 0 (control group), 40, 60, 80, and 100 mg/kg β-sitesterol for 42 days, respectively. Data were analyzed by one-way analysis of variance. Polynomial contrasts were used to test the linear and quadratic response to β-sitosterol levels. Difference among groups was evaluated using Tukey’s test, which was considered significant if P < 0.05. Dietary β-sitosterol linearly increased (P < 0.05) contents of serum immunoglobulin G and hepatic glutathione, activities of serum superoxide dismutase and catalase, whereas linearly decreased (P < 0.05) concentrations of serum tumor necrosis factor α and hepatic malondialdehyde. Serum interleukin 1β level was linearly and quadratically reduced by β-sitosterol inclusion (P < 0.05). Compared with the control group, dietary β-sitosterol with higher levels than 60 mg/kg increased concentrations of serum immunoglobulin G and hepatic glutathione, activities of serum superoxide dismutase and catalase (P < 0.05), whereas decreased serum tumor necrosis factor α content (P < 0.05). Its dosages higher than 40 mg/kg reduced serum interleukin 1β content (P < 0.05), and 100 mg/kg of which lowered hepatic malondialdehyde concentration (P < 0.05). The results indicated that dietary β-sitosterol could improve immunity and antioxidant ability in broilers. Also, a level of 80 mg/kg β-sitosterol supplementation was recommended into broiler diet.
PSIX-9 Dietary β-sitosterol improves immunity and antioxidant status in broilers
