Dietary coated essential oil and organic acid mixture supplementation improves health of broilers infected with avian pathogenic .

Colibacillosis caused by avian pathogenic (APEC) is a very prevalent disease in poultry farms in China. The exploration of effective non-antibiotic substances is of great significance for the control of APEC infections. This experiment evaluated the efficacy of coated essential oil and organic acid (EOA) supplementation to prevent O78 infection in broiler chickens. A total of 288 one-day-old male broiler chicks were randomly distributed into 4 groups with 6 replicates per group. Chickens were fed a diet either supplemented with EOA (500 mg/kg feed) or not, and either uninfected or infected with O78 intratracheally. Results showed that O78 infection reduced body weight gain, increased mortality and the ratio of feed to gain along with cecal and liver load, damaged gut mucosa, induced local and systemic inflammation, and altered cecal microbial composition, diversity and function ( 0.05). Supplemental EOA improved feed conversion efficiency, lowered gross lesion scores and cecal population, enhanced intestinal goblet cells and serum IgG concentration, and tended to decrease serum IL-12 production ( 0.05). Essential oil and organic acid addition downregulated mRNA, tended to decrease mucin-2 mRNA levels while upregulating 10 mRNA, and tended to increase gene expression in the jejuna of infected birds at 7 d after O78 challenge (). The 16S rRNA gene sequencing indicated that both EOA addition and O78 challenge altered the diversity and composition of the cecal microbiota community. Furthermore, infected birds fed EOA showed decreased Bacteroidetes and genus abundance compared with the infected control. LEfSe analysis showed that Firmicutes, Ruminococcaceae, Clostridiales Clostridia Lactobacilaceae and were enriched in the non-infected but EOA-treated group ( 0.05). Collectively, dietary EOA supplementation could mildly alleviate -induced gut injury and inflammation.