Effects of fermented rapeseed meal on growth and serum indices in white male muscovy ducks

To study the effects of supplementing diet with varying doses of fermented rapeseed meal on growth and serum indices in white male muscovy ducks, four-hundred and eighty 28-day-old white male muscovy ducks all of the same hatching cohort and of similar body weight were randomly divided into 4 groups, with 6 replicate subgroups of 20 ducks each. Ducks in the control group were fed a corn-soybean basal diet. Ducks in the experimental groups were fed the basal diet supplemented with 12%, 16%, or 20% fermented rapeseed meal. The experimental period was 21 days. The results are as follows: 1) the final body weight and average daily weight gain in the control group and the 16% group were significantly higher than those in the other groups (P < 0.05). The average daily feed intake in the control group was significantly higher than that in the other groups (P < 0.05). 2) Serum total protein, total cholesterol, high-density lipoprotein, and low-density lipoprotein were significantly lower in the 16% group than in the 12% group (P < 0.05). Alanine transaminase and alkaline phosphatase activities were significantly higher in the 16% group than in the 12% group (P < 0.05), but tetraiodothyronine concentrations displayed an opposite trend. 3) Superoxide dismutase activity was significantly lower in the 16% group than in the control group (P < 0.05). No significant differences were observed in other indices of antioxidant functions. In conclusion, fermented rapeseed meal can be added to the diet without negatively impacting the growth performance of ducks. Supplementation with 16% fermented rapeseed meal had good efficacy in this study.