A Scientific Review of Butyrate Supplementation on Animal Performance
Among SCFAs, butyrate has received more attention for its beneficial effects on both cellular energy metabolism and intestinal homeostasis. As much as 90% of butyrate is metabolized by the colonic epithelial cells making it a major metabolite for the colonic epithelial cells
Short chain fatty acids (SCFA) are organic fatty acids with up to 6 carbons produced within the intestinal lumen by bacterial fermentation of undigested dietary carbohydrates, and to a lesser degree, dietary and endogenous proteins such as sloughed epithelial cells and mucous (Topping and Clifton, 2001). The SCFAs most abundant in the gastrointestinal tract (GIT) are acetate, propionate and butyrate. The production of these SCFA allows the salvage of energy mainly from carbon sources not digested in the small intestine. Among SCFAs, butyrate has received more attention for its beneficial effects on both cellular energy metabolism and intestinal homeostasis. As much as 90% of butyrate is metabolized by the colonic epithelial cells making it a major metabolite for the colonic epithelial cells (Hamer et al., 2008).
Butyrate is pungent making it unpleasant to work with and can discourage animals from consuming feed with free butyrate added. Furthermore, majority of free butyrate has been shown to be largely absorbed in the upper GIT, leaving very little reaching the large intestines where butyrate would exert its major functions (Pituch et al., 2013). Consequently, butyrate glycerides, butyrate salts, and different encapsulation techniques have been developed and used in order to ease the handling and allow for slow release of butyrate in the GIT.
It has been recently reported that streptomycin treatment causes a depletion of butyrate producing Clostridia from a mouse intestinal lumen, leading to decreased butyrate levels, increased epithelial oxygenation and increase of Salmonella enterica. These effects could be reversed by tributyrin treatment (Rivera-Chávez et al., 2016). A study on the effect of sodium butyrate supplementation on bacterial infection in broilers found that both encapsulated and free sodium butyrate were effective in relieving Salmonella burdens in birds (Fernández-Rubio et al., 2009). This suggests that the slow release from protected sodium butyrate is possibly more effective because it is released along the digestive tract. Sodium butyrate has also been shown to moderate immune response of broiler chickens and improve growth performance in broilers under stress (Zhang et al., 2011). Sodium butyrate uses in layer hens allowed for egg production and egg characteristic enhancement such as stronger shells (Arnouts et al., 2002). Birds supplemented with butyrate derivatives (monobutyrin, tributyrin or their mixture) observed a decrease in abdominal fat and increase in relative breast muscle weight (Bedford et al., 2017, Yin et al., 2016).
The weaning transition of piglets is stressful and often causes a growth lag post weaning due to underdeveloped GIT during early weaning. Pigs supplemented with butyrate and its derivatives also experience positive effects on the development of GIT. When supplemented to piglets suffering from intrauterine growth restriction (IGR) body weight was improved. Spleen and small intestine development were also improved compared to unsupplemented IGR piglets.
Note: References available upon request.
By Kayla Wong, Technical Specialist, Manuka Biotech