The aim of this study was to investigate the effects of tributyrin supplementation on production traits, key metabolic parameters and gut microbiota in weaned piglets. 120 hybrid piglets (Large White×Landrace) were randomly divided into two experimental groups (6 pens per group; 10 piglets per pen): control group (CTRL) receiving basal diet and tributyrin group (TRIB) Receive a basal diet supplemented with 0.2% tributyrin.

Tributyrin is an effective substitute for butyric acid because one molecule of tributyrin releases three molecules of butyric acid directly in the small intestine, so butyric acid is absorbed quickly. Tributyrin supplementation showed variable positive effects on in vivo growth performance and gut health after lipopolysaccharide challenge [16,17,18]. Higher growth performance and improved protein digestibility suggest that tributyrin can regulate protein and lipid metabolism. Therefore, blood metabolites, insulin and leptin, which are positively correlated with body weight, fat and muscle mass, can be modulated by tributyrin supplementation. However, no other studies have investigated the effects of dietary tributyrin on blood metabolites (such as glucose, urea, and HDL), insulin, leptin, and cortisol in healthy piglets. Therefore, the aim of this study was to determine the effects of tributyrin supplementation on production traits and nutrient metabolism in piglets raised in conventional herds. In particular, the major blood metabolites, insulin, leptin, hair cortisol and protein content in the stool samples were analyzed. Furthermore, the effect of tributyrin on the gut microbiota was assessed. In contrast, tributyrin significantly reduced urea blood concentrations (p = 0.0026), which correlated with lean mass gain and feed efficiency. In addition, serum insulin concentrations, which regulate protein and lipid metabolism, were significantly higher in the TRIB group (p = 0.0187). In conclusion, this study shows that tributyrin can be considered as an effective feed additive for weaned piglets.