Evaluation of application effect of hydrolyzed chicken powder in feed for largemouth bass (Micropterus salmoides)

To investigate the effects of replacing fish meal with hydrolyzed chicken powder on growth performance, feed efficiency and liver antioxidant capacity of largemouth bass. Four isonitrogenous and isolipid diets were formed by adding 5.57%, 11.16% and 16.73% hydrolyzed chicken powder to replace 16.7% (FM25), 33.3% (FM20) and 50% (FM15) fish meal with 30% fish meal as the control group. Largemouth bass with an initial body weight of (15.76 ± 0.12) g were randomly divided into 4 groups with 3 replicates per group at a density of 30 individuals per replicate. Each diet was randomly assigned to triplicate tanks, and the feeding trial lasted for 63 days. The results showed that the replacement of fish meal with hydrolyzed chicken powder had no significant effect on survival rate of largemouth bass. The growth performance of largemouth bass were significantly decreased, and meanwhile, feed conversion ratio significantly increased, with the increase of fish meal replacement level, the feed conversion ratio of FM15 group was 0.86, which was still lower than that of commercial feed in production practice (0.9-1.0). The viscerosomatic index of largemouth bass in FM15 group was significantly lower than that in FM25 and FM20 groups. The results of antioxidant capacity showed that the liver malondialdehyde content of largemouth bass in FM25 group was significantly lower than that in other groups. Meanwhile, the total antioxidant capacity of largemouth bass in FM30 and FM25 groups was significantly higher than that in the other two groups. In conclusion, dietary hydrolyzed chicken powder can improve the antioxidant capacity of largemouth bass. Although the addition of hydrolyzed chicken powder can decrease the growth performance of largemouth bass, the feed conversion ratio of largemouth bass is still significantly higher than that of commercial feed. Meanwhile, the fish meal replacement with appropriate hydrolyzed chicken powder (5.57%) can effectively improve the antioxidant status of largemouth bass. This indicates that hydrolyzed chicken powder has a wide application prospect in the low fish meal diet of largemouth bass.