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

Four isonitrogenous and isolipid diets were formed by adding 5.57%, 11.16% and 16.73% hydrolysed chicken powder to replace 16.7% (FM25), 33.3% (FM20) and 50% (FM15) fish meal, with 30% fish meal as the control group to investigate the effects of replacing fish meal with hydrolyzed chicken powder on the growth performance, feed efficiency and liver antioxidant capacity of largemouth bass (Micropterus salmoides). Largemouth bass with an initial body weight of (15.76 ± 0.12) g were randomly divided into four groups with three 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 hydrolysed chicken powder had no significant effect on the survival rate of largemouth bass. The growth performance of largemouth bass was significantly decreased, and the feed conversion ratio was significantly increased. As the fish meal replacement level inceased, the feed conversion ratio of FM15 group was 0.86, which remained 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 those in the other groups. Meanwhile, the total antioxidant capacity of largemouth bass in FM30 and FM25 groups were significantly higher than that in the other two groups. In conclusion, dietary hydrolysed chicken powder can improve the antioxidant capacity of largemouth bass. Although the addition of hydrolysed 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 hydrolysed chicken powder (5.57%) can effectively improve the antioxidant status of largemouth bass. This indicates that hydrolysed chicken powder has a wide application prospect in the low fish meal diet of largemouth bass.