Effect of microbial preparation on intestinal microbiota in crucian carp.

The experiment aimed to investigate the effects of microbial preparations on the growth and intestinal microbiota of crucian carp. Three hundred evenly sized crucian carp were randomly divided into five groups, with three replicates in each group, and 20 fish in each replicate. The group A was fed a feed containing mixed lactic acid bacteria preparations, the group B was fed a feed containing mixed Clostridium butyricum preparations, the group C was fed a feed containing a mixture of lactic acid bacteria and Clostridium butyricum preparations, the group D was fed a feed containing a mixture of lactic acid bacteria, Clostridium butyricum preparations, and 3 mg/g nano-selenium. The control group (CK group) was fed a basic feed. The experimental period lasted for 28 days. The results showed that the weight gain rate of crucian carp in the group A, group B, and group D was higher than that in the CK group ( P<0.05). The condition factor and feed coefficient of crucian carp in the group A were higher than those in the CK group ( P<0.05). The hepatopancreas SOD activity of crucian carp in the group D was higher than that in the CK group ( P<0.05), and the hepatopancreas LZM activity in the group B was higher than that in the CK group ( P<0.05). The abundance of Fusobacteria in the intestines of crucian carp in the group A significantly increased, while the abundance of Bacteroidetes in the intestines of crucian carp in the group B significantly increased. The study indicates that adding lactic acid bacteria, Clostridium butyricum, and nano-selenium to the feed can promote the growth of crucian carp, alter the community structure of the intestinal microbiota, and inhibit harmful bacteria in the intestines. [ABSTRACT FROM AUTHOR]