复合酶在白羽肉鸡低蛋白日粮中的应用效果研究.

This study was conducted to study the effects of compound enzyme supplementation within a low-protein diet on the growth performance, serum biochemical and antioxidant parameters, immune function, and digestive organ development in white-feather broilers. A total of 288 one-day-old white-feathered broilers were randomly distribute six treatment groups. The trial spanned 42 days and comprised two dietary formulation stages: 1- 21 days and 22-42 days. The control group (CK) received a conventional protein diet with protein levels of 21.28% and 19.04% during the respective stages. Other treatment groups received a low-protein diet with crude protein levels 0.97% and 0.94% lower than the CK group for the same periods. The groups T1, T2, and T3 were supplemented with 200 mg/kg complex enzyme A, 200 mg/kg complex enzyme B, and 300 mg/kg complex en‐ zyme B, respectively. Moreover, the T4 groups was supplemented with 100 mg/kg and 300 mg/kg com‐ plex enzyme B enzyme in the first and second stages, respectively. And the T0 group received the low-protein diet without enzyme supplementation. The results showed that the T2, T3 group exhibited significantly higher values for 21-day live weight, 42-day live weight, and the production index compared to other groups. Additionally, the feed-to-weight ratio for the entire 1-42 days period was lower in the T3 group. Serum urea levels in the CK and T3 groups were significantly lower than those in the T4 group (P<0.05). Conversely, the serum aspartate aminotransferase content in the T2 group was notably higher than T0, T3 and T4 groups (P<0.05). Serum superoxide dismutase content in the T0, T1, and T2 groups was significantly lower than in the T4 group (P<0.05). Furthermore, T4 group displayed significantly higher levels of IgA, IgG, and IgE compared to the T0 group (P<0.05). In conclusion, the incorporation of compound enzymes into the low-protein diet of white-feathered broilers enhances the biochemical and antioxidant capacity of white-feathered broilers, promotes the development of immune organs and diges‐ tive organs, and improves immunity. [ABSTRACT FROM AUTHOR]