Evaluation of an essential oil blend derived from thymol, cinnamaldehyde, and menthol on the growth performance and gut health of broiler chickens

The study aimed to assess the effects of different levels of essential oil blend on the growth performance, gut health, and immune response of broiler chickens.A total of 192 day-old straight run broiler chicks were randomly assigned to four experimental groups, each comprising of 48 chicks divided into six replicates with eight chicks in each.The dietary groups included: basal diet without any growth promoter (CON) (group-1), basal diet with antibiotic (Bacitracin methylene disalicylate -BMD) @500 g/ton feed (AGP) (group-2), basal diet with essential oil blend @100 mg/kg feed (EOB100) (group-3) and basal diet with essential oil blend @200 mg/kg feed (EOB200) (group-4).Body weight gain, feed consumption, and feed conversion ratio were monitored at various intervals.Blood samples were collected for analysis, and antibody titers were measured.Carcass traits, gut microbiome, and gut morphology were evaluated at the end of the trial.Results showed that the EOB200 group had significantly higher (P<0.05)final body weight and average daily gain compared to other groups.Both EOB200 and EOB100 groups showed significantly improved (P<0.05) feed conversion ratio.EOB200, EOB100, and AGP groups had lower Escherichia coli and Salmonella sp counts and higher Lactobacillus counts.Villi height in the duodenum and ileum was significantly higher (P<0.05) in the EOB200 group.Essential oil blends 200 mg/kg feed could be effective alternatives to antimicrobials in poultry production.