Effects of microencapsulated essential oils on growth performance and biomarkers of inflammation in broiler chickens challenged with salmonella enteritidis

Abstract

Feed ingredients are the potential sources, which can be contaminated with Salmonella. Therefore, the alternative strategies should be found for controlling pathogenic microbes and promoting the performance of broiler chicks. Although antibiotics have been used for the treatment of the infection induced by microbes, the use of which faces with some limitations such as bacteria resistance. The antibiotic substitute should be natural with no residue in poultry meat. Compounds such as phytobiotics can be incorporated into the diet for enhancing the production of poultry with no concern about the appearance of antibiotic-resistant microbial species and remaining the residue in the meat. This study aims to synthesize the microcapsules preserving the mixture of essential oils including thyme, peppermint, savory, and black pepper by using spray drying technique and to evaluate the growth performance, antioxidant status, immune response, and gut health parameters in broiler chickens challenged by salmonella enteritidis. The mixture of essential oils including thyme (50%), summer savory (25%), peppermint (12.5%) and black pepper seed (12.5%) was encapsulated in the protecting wall materials (20% WPC, 25% MS and 55% MD) for forming the essential oil-loaded spherical microcapsules with particle size of 323 nm and encapsulation efficiency of 96.2%. Thymol, carvacrol, p-cymene, γ-terpinene, and menthol existed in the core of the microcapsules as the main bioactive compounds. The microcapsules possessed the antioxidant and antibacterial activities, and its dietary application as the feed additive at the concentrations of 0.5, 1 and 2 kg/ton in broiler chickens challenged by S. enteritidis improved the final weight, total feed intake, FCR, body antioxidant status, ileal morphostructure, intestinal microbial population and regulated the antioxidant and inflammation genes in ileal tissue and upregulated the expression of occludin and SOD genes.