Effect of Chinese gallnuts tannic acids on the growth performance, intestinal morphometry and microbiome of broiler chickens.

The rise in global restrictions on antibiotic growth promoters have intensified the search for sustainable and safe alternatives. Phytogenic feed additives (PFAs) have emerged as promising contestants because of their diverse biological properties. This research studied the potential effects of herbal extracts as the standardized PFA containing tannic acids derived from Chinese gallnuts on intestinal morphometry, growth performance and cecal microbiota. For this purpose, 224 one-day-old male Ross 308 broiler chicks were allocated to 28 cages, with eight birds per cage and seven replicate cages per treatment, in a 35-day trial. The four dietary treatments were: negative control (NC) without antibiotic growth promoters, NC + avilamycin at 100 g/t, NC + colistin sulfate at 100 g/t, and NC + Chinese gallnuts tannic acids (CGTA) at 200 g/t. The growth performance indices were observed during the whole production cycle. The intestinal morphometry was observed on the day 35. The dietary inclusion of CGTA significantly improved feed conversion ratio (FCR) during 0 to 10 and 0 to 21 days as compared to NC diet treatment. Moreover, the European Production Efficiency Factor (EPEF) of 441 was also observed numerically higher in the CGTA supplementation treatment. Additionally, the intestinal morphometric analysis revealed a substantial rise in both the duodenal and jejunum height of villus and a decrease in epithelial thickness in both duodenum and jejunum, indicating the enhanced absorptive capacity and gut integrity. Crypt depth and goblet cell numbers were not affected significantly. Notably, microbiota analysis showed no significant differences in alpha or beta diversity. In conclusion, dietary supplementation of CGTA at 200 g/t improved feed efficiency and intestinal morphometry in broilers, without altering the community of cecal microbiota.