A Preliminary Study on the Effect of Replacing Part of Fishmeal by Brewer’s Yeast in Feeding Taiwan Loach

In this experiment, brewer’s yeast was used to replace part of the fish meal in the feed to formulate a high-fat and low-protein feed for Taiwan loach. The effects of brewer’s yeast on the growth performance, muscle quality, hepatopancreas and pancreas carnitine content, intestinal flora, immunity, and antioxidant ability of Taiwan loach were preliminarily investigated. In experiment 1, 600 Taiwan loaches were randomly divided into 4 groups, and 1% (group A), 4% (group B), 8% (group C), and 12% (group D) of brewer’s yeast was substituted for an equal amount of fishmeal in the basal diets. The loaches in each group were fed for 60 d. In experiment 2, 60 Taiwan loaches were selected and randomly divided into a control group (Group E) and a test group (Group F). The loaches were fed the basal diet and the high-fat and low-protein diet supplemented with 8% fishmeal, replaced by brewer’s yeast. The experiment lasted for 60 days, and the growth performance, hepatopancreas carnitine content, muscle quality, intestinal flora, plasma antioxidant, and immune capacity indices of loaches in each group were determined. The results were as follows: the weight gain rate and specific growth rate were significantly higher in group C than those in groups A, B, and D (P < 0.05); the intestinal length ratio, muscle hardness, hepatopancreatic carnitine content, plasma superoxide dismutase activity, catalase activity, total antioxidant capacity, and lysozyme activity were significantly greater in group F than those in group E (P < 0.05); the Lactobacillus and Bifidobacterium counts in Group F were considerably higher than those in Group E (P < 0.05), and the Salmonella counts in Group F was significantly lower than that in Group E (P < 0.05); the survival rate, weight gain rate, bait coefficient, muscle crude protein, crude fat, viscosity, elasticity, cohesion, chewability, and restorative capacity were not significantly different between Group F and Group E (P > 0.05). The above results showed that adding 8% brewer’s yeast to feed Taiwan loach instead of fish meal could enhance its hepatopancreatic carnitine synthesis, optimize the intestinal flora, improve the body’s immune and antioxidant ability, and have a certain promotional effect on the intestinal development and muscle quality improvement.