Dietary butyrate effects on broiler growth, intestinal morphology and integrity, cecal volatile fatty acid concentrations, and colonic bacteria in broilers

Authors: Pearce, Sarah; Kerr, Brian; Monson, Melissa; RAMIREZ, SHELBY - Oak Ridge Institute For Science And Education (ORISE)

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/23/2025
Publication Date: 9/24/2025
Citation: Pearce, S.C., Kerr, B.J., Monson, M.S., Ramirez, S.M. 2025. Dietary butyrate effects on broiler growth, intestinal morphology and integrity, cecal volatile fatty acid concentrations, and colonic bacteria in broilers. Poultry Science. https://doi.org/10.1016/j.psj.2025.105898.
DOI: https://doi.org/10.1016/j.psj.2025.105898

Interpretive Summary: Short chain fatty acids are products of microbial fermentation in the intestinal tract, of which butyric acid is the most important for intestinal function and immune modulation. Available data show that the effects of feeding dietary butyrate to boilers are variable. Therefore, we conducted a study to determine the effects of unprotected and protected butyrate on growth, intestinal fatty acid concentrations, and intestinal function of growing broilers. The data showed that adding either unprotected or protected butyrate had no effect on broiler growth, on intestinal short chain fatty acid concentrations, or on intestinal morphology. In contrast, birds fed with diets containing protected butyrate had some positive impacts on gene activity associated with intestinal function and on inflammatory genes in several body tissues. This information is important to nutritionists at universities, feed companies, and broiler production facilities regarding the impact of dietary butyrate on the broiler's physiological functions or on overall performance productivity.

Technical Abstract: Four hundred and sixty-eight broiler chicks were housed in 39 pens, 12 birds per pen, and fed a three-phase feeding regimen for 42 d. There were three dietary treatments which consisted of birds being fed a negative control diet, a diet containing 260 mg of unprotected sodium butyrate, or a diet containing 260 mg/kg diet of a fat matric encapsulated butyrate, resulting in 13 replications per dietary treatment. Performance parameters (daily gain, daily feed, and gain to feed ratio) were obtained for the overall feeding study. Following the performance trial, on d 42, 4 birds per pen were randomly selected and euthanized for cecal fluid collection for subsequent pH and VFA analysis. Also on d 42, 1 bird per pen from 6 pens were randomly selected and euthanized for collection of jejunum and colon tissue collection for intestinal morphology evaluation. In addition, 1 bird per pen from 8 pens were randomly selected and euthanized for collection of cecum, cecal tonsil, crop, and spleen tissues for RNA isolation and quantitative PCR evaluation. Lastly, on d 43, 1 bird per pen was randomly selected and euthanized for collection of fresh jejunum and colon selection for ex vivo assessment of intestinal integrity and barrier function. There was no effect of dietary treatment on feed intake or feed efficiency (P > 0.10) with a tendency for gain to increase due to dietary butyrate, regardless of source (P = 0.07). There was no effect of dietary butyrate on cecal pH, propionate, butyrate, or total VFA (P > 0.10) with a tendency for butyrate, regardless of source to reduce acetate concentrations (P = 0.07). There was no effect of dietary butyrate on intestinal morphology in the jejunum or colon (P > 0.10). Diets containing protected butyrate had some positive impacts on gene expression of tight junction and inflammatory genes in the cecum as well as inflammatory genes in the cecal tonsil, spleen, and crop. In general, dietary butyrate, regardless of source, exhibited little effect on performance or most physiological measures.