Effects of Artificial Compound Feed for Live Fish Feed on Growth Performance, Nutrient Composition, Digestive Performance, and Gut Microbiota of Giant Salamander (Andrias davidianus)

This study explored the effects of replacing live fish feed with artificial compound feed on the growth performance, nutritional composition, digestive performance, and gut microbiota of Chinese giant salamander (Andrias davidianus). The experiment was divided into three groups, each with three biological replicates. The salamander juveniles were fed artificial compound feed (S), live fish (H), and frozen fish (D) for 184 days. Results showed no significant differences in growth performance among the three groups (p > 0.05). The water content in the S group was significantly higher than that in the H group (p < 0.05), and the crude fat content was slightly higher, whereas other nutritional components showed no significant differences (p > 0.05). The analysis of amino acid composition found no significant differences among the three groups of Chinese giant salamanders (p > 0.05). The analysis of fatty acid composition revealed that the feed group had significantly lower levels of polyunsaturated fatty acids compared with the other two groups (p < 0.05), and significantly higher levels of saturated fatty acids (p < 0.05). There were no significant changes in digestive enzyme activity among the three salamander groups (p > 0.05). There were also no significant differences in the remaining antioxidant indicators in the intestine and liver among the three groups of salamanders (p > 0.05). The S group had significantly higher Pielou_e and Shannon indices (p < 0.05), thereby indicating a greater diversity and evenness of the gut microbiota. In conclusion, replacing live feed with artificial compound feed does not affect the growth performance, nutritional composition, antioxidant capacity, and digestive function of Chinese giant salamander juveniles. Moreover, it enhances the diversity and richness of the gut microbiota, providing effective data to support the development of artificial feeds for giant salamanders.