Thymol-carvacrol supplementation in broilers: impact on performance, blood biomarkers, and gut health

The stress conditions are induced by a high-dose live coccidiosis vaccine, and thymol-carvacrol supplementation in broilers were significantly improved the feed conversion ratio (FCR) during the starter and grower phases as compared to the negative control. In contrast, antibiotic supplementation resulted in better growth performance throughout the rearing period. In addition, antibiotic supplementation lowered serum levels of the oxidative stress marker malondialdehyde (MDA) and the pro-inflammatory cytokine interleukin-17 (IL-17), with thymol-carvacrol supplementation showing comparable but less pronounced effects, followed by the negative control. In addition, antibiotic supplementation improved intestinal morphology as evidenced by the decreased crypt depth and increased villus height to crypt depth ratio, followed by thymol-carvacrol supplementation compared to the non-supplemented groups. These results suggest that thymol-carvacrol supplementation can improve the gut health and performance of broilers under stress conditions.