Effects of Dietary Butyrate Supplementation on Digestive Physiology, Feed Utilization, and Growth Performance in Crustaceans: A Meta-Analysis and Meta-Regression

Butyrate, a short-chain fatty acid (SCFA), is increasingly recognized as a functional feed additive in aquaculture. However, its effects on crustacean health and performance remain unclear. This meta-analysis synthesizes findings from 23 studies (2011–2025) examining butyrate supplementation across four crustacean groups: shrimp, crabs, crayfish, and prawns. Effect sizes were calculated for growth performance (final body weight, specific growth rate, survival rate), feed efficiency (feed conversion ratio, protein efficiency ratio), and digestive enzyme activities (amylase, lipase, alkaline phosphatase, total protease) in freshwater and marine environments. Results indicate that butyrate supplementation generally enhanced the digestive enzyme activity in both freshwater and marine environments, although the magnitude of the effect varied among enzyme types and habitats, with freshwater species showing improvements in alkaline phosphatase, amylase, lipase, and total protease, and marine species showing improvements in amylase, lipase, and total protease. Feed efficiency improved in freshwater (protein efficiency ratio) and marine species (feed conversion ratio). Growth-related outcomes, including final body weight and survival rate, were generally improved across both environments. Dose–response analyses indicated that dietary inclusion levels of 1–2% were associated with the most consistent improvements in digestive enzyme activity and growth performance. These findings support the potential use of butyrate as a functional feed strategy to improve productivity and sustainability in crustacean aquaculture. These effects may be mediated by multiple mechanisms, including improved intestinal epithelial integrity, the modulation of gut microbiota, and the regulation of immune and metabolic processes.