Effects of Weizmannia Coagulans on Growth Performance, Immunity and Intestinal Histology of Juvenile Micropterus salmoides

A 30-day single factor feeding test was conducted to investigate the effects of dietary supplementation with 0.05% Weizmannia coagulans on the growth performance, intestinal health and immune function in juvenile Micropterus salmoides with the body weight of (1.05±0.05) g·tail⁻¹, while the control group was not added. The results showed that Weizmannia coagulans significantly increased the weight gain rate (P＜0.01) and specific growth rate (P＜0.01), while the feed coefficient was significantly reduced (P＜0.01). The histological analysis showed that the length of intestinal villus and the thickness of muscle layer in the experimental group were significantly increased, and the degree of liver vacuolization was reduced. Furthermore, Weizmannia coagulans significantly increased the intestinal alkaline phosphatase (P＜0.01) and acid phosphatase activity (P＜0.01), while the hepatic catalase (CAT) and total antioxidant capacity (T-AOC) activity were significantly enhanced (P＜0.05). This study confirmed that Weizmannia coagulans could significantly improve the growth performance and health status of juvenile Micropterus salmoides by promoting the secretion of digestive enzymes, improving the intestinal morphology and strengthening the antioxidant defense system, providing a scientific basis for its application in aquaculture.