Effects of probiotic and butyrate-based feed additives on growth performance, carcass yield and gut health of broiler chickens.

The current study was conducted to evaluate the effects of different probiotic and butyrate-based feed additives on the growth performance, carcass yield, blood biochemistry, intestinal microbiota, and ileal histomorphology of broiler chickens under heat stress condition. A total of 625 one-day-old Ross 308 broiler chicks were randomly divided into five dietary treatment groups. The treatments included a control group (fed a basal diet) and four supplemented groups (each consisting of five replicates with 25 birds/ replicate). The feed additives included Saccharomyces boulardii, Bacillus subtilis PB6, protected sodium butyrate, and a sodium-calcium butyrate blend, each incorporated into the basal diet at specified commercial doses. The results showed that the inclusion of protected sodium butyrate and sodium-calcium butyrate consistently enhanced broiler growth performance and increased feed intake without negatively affecting the feed conversion ratio. Reductions in ALT, and AST observed in the supplemented groups suggest that probiotics and butyrate exert beneficial modulatory effects on liver function. Additionally, all tested feed additives improved intestinal development, as indicated by increased villus height and enhanced villus: crypt ratios. A complete absence of harmful microorganisms was observed in birds receiving Bacillus subtilis or sodium butyrate. These findings provide new insights into using sodium butyrate based feed additives in broilers diet.