Dietary supplemental coated essential oils and organic acids mixtures improves growth performance and gut health along with reduces Salmonella load of broiler chickens infected with Salmonella Enteritidis

Abstract

Abstract Background: Reducing Salmonella infection in broiler chickens by using effective and safe alternatives to antibiotics is vital to provide safer poultry meat and minimize the emergence of drug-resistant Salmonella and the spread of salmonellosis to humans. This study was to first evaluate the protective efficacy of feeding a novel coated essential oils and organic acids mixtures (EOA) on broiler chickens infected with Salmonella Enteritidis (S. Enteritidis, SE), and then its action mechanism was further explored. Methods: 480 1-day-old Arbor Acres male chickens were randomly assigned into five treatments with six replicates, including non-challenged control fed with basal diet (A), SE-challenged control (B), and SE-infected birds fed a basal diet with three levels of EOA (300mg/kg, 500mg/kg and 800mg/kg) (BL, BM and BH), respectively. All birds on challenged groups were infected with SalmonellaEnteritidis at 13 days of age. Results: Feeding EOA showed a reversed ability on negative effects caused by S. Enteritidis infection, as evidenced by decreasing the feed conversion rate (FCR) and the ratio of villus height to crypt depth (VH/CD) (P < 0.05), obviously decreasing intestinal and internal organs Salmonellaload along with increasing cecal butyric acid-producing bacteria abundance (P < 0.05). Moreover, supplemental different levels of EOA notably up-regulated Claudin-1, Occludin, zonula occludens-1 (ZO-1), mucin-2 (MUC-2), fatty acid binding protein-2 (FABP-2), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), myeloid differential protein-88 (MyD88) and interleukin-6 (IL-6) mRNA levels, whereas down-regulated toll-like receptor-4 (TLR-4) mRNA levels in the ileum of the infected chickens (P < 0.05). Linear discriminant analysis combined effect size measurements analysis (LEfSe) showed that the relative abundance of g__Butyricicoccus, g__Anaerotruncus and g__unclassified_f__Bacillaceaesignificantly was enriched in infected birds given EOA. Also, phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis showed that alpha-linolenic acid metabolism, fatty acid metabolism and biosynthesis of unsaturated fatty acids were significantly enriched in the EOA group. Conclusion: Our data suggest that the novel essential oils and organic acids mixturescan be used as an antibiotic substitute to control Salmonella Enteritidis infection in broiler chickens.