Effects of dietary sodium acetate on growth, intestinal microbiota composition, and ammonia tolerance of juvenile yellow catfish Pelteobagrus fulvidraco

Short-chain fatty acids (SCFAs), such as acetates, play a role in modifying metabolic disorders and regulating the homeostasis of the organism. In this study, the impact of dietary sodium acetate (SA) on growth, intestinal microbiota composition, and ammonia tolerance of yellow catfish. During a 56-day study, four groups of yellow catfish weighing an average of 2.72 ± 0.11 g were provided with diets containing varying proportions of SA. The diets included 0%, 0.1%, 0.2%, and 0.4% SA. Each batch consisted of three replicates, with each replicate containing 40 fish. The results indicated that dietary supplemented with 0.2% SA had significantly higher weight gain and specific growth rates than those in 0% and 0.1% groups. The feed efficiency ratio in 0% groups was significantly the highest. Dietary SA can significantly increase the activities of intestinal lipase, amylase, and pepsin, and the contents of liver total protein, immunoglobulin M, and 50% hemolytic complement, while decreasing the contents of liver triglyceride, glucose, high-density lipoprotein cholesterol, aspartate aminotransferase, alanine aminotransferase, tumor necrosis factor-α, interleukin-1, and interleukin-8, and the activities of liver superoxide dismutase, and catalase. In addition, dietary SA significantly increased the relative abundance of beneficial bacteria (Achromobacter) and production of butyrate, meanwhile decreasing the harmful bacterial (Rhodobacter) abundance. After the challenge, cumulative mortality in fish fed 0% SA diets was higher than in fish fed 0.1–0.5% SA diets after 96 h ammonia stress. Correlation analysis showed that the SA induced the enhancement of the metabolic efficiency of carbohydrates, amino acids, and lipids were also associated with the increased relative abundance of Achromobacter. In general, SA can function as a beneficial additive for enhancing growth, intestinal health, and ammonia tolerance in yellow catfish.