Evaluation of Microencapsulated Essential Oils in Broilers Challenged with Salmonella Enteritidis: A Focus on the Body’s Antioxidant Status, Gut Microbiology, and Morphology

Restrictions on antibiotic use encourage researchers to seek natural substitutes with the same effects without adverse end effects resulting from antibiotic use. Savory and black pepper have been challenged against Salmonella enteritidis (S. enteritidis) bacterium using the spray dryer method to evaluate growth performance, antioxidant status, immune response, and intestinal health parameters in broilers. In this study, thyme essential oil (50%), savory (25%), peppermint (12.5%), and black pepper seeds (12.5%) were mixed to form essential oilloaded spherical microcapsules with the particle size of 323 nm and encapsulation efficiency of 96.2%. The main bioactive compounds used in the core of microcapsules included thymol, carvacrol, p-cymene, γ-terpinene, and menthol. Moreover, modified starch (25%) and maltodextrin (55%) were used for the preparation of spherical microcapsules for the enclosed wall with 20% whey protein concentrate. The dietary addition of microcapsules containing essential oil significantly reduced the S. enteritidis population in both ileum and cecum (P<0.05). The results revealed that the dietary inclusion of essential oil-loaded microcapsules significantly (P<0.05) increased the villus height, villus width, V: C ratio, and the number of goblet cells and decreased the crypt depth. Microcapsules have antioxidant and antibacterial activity and their dietary use as feed additive at 0.5, 1, and 2 kg/t concentrations in broilers has been challenged and showed that the final weight, total feed intake, and FCR improved the body’s antioxidant status, structure, and inflammation in the ileum tissue.