Effects of dietary essential oil and enzyme supplementation on growth performance and gut health of broilers challenged by Clostridium perfringens

• C. perfringens challenged model was used to dicuss protective effects of enzyme and essential oils.

An experiment was carried out to evaluate the effects of dietary supplemental essential oil comprising thymol and carvacrol (EO), and enzyme complex containing xylanase, glucanase and mannanase as major components (CSM) on Clostridium perfringens challenged model in broilers. A total of 648 1-d-old female broiler chicks were assigned to eight groups. A 2 × 2 × 2 factorial arrangement of treatments was used in a randomized complete block design to study the effects of essential oil supplementation (with or without EO 60 mg/kg diet), enzymes addition (with or without CSM 500 mg/kg diet), pathogen challenge (with or without C. perfringens challenge from d 14 to 20), and the interactive effects. A pelleted high NSP wheat–soybean meal basal diet was formulated to meet nutrient requirements recommended by NRC (1994). Body weight, feed intake, and feed to gain ratio were determined on d 14, 21 and 35; ileal digesta viscosity, intestinal lesion score, ileal histomorphologic indices, bacterial population and plasma endotoxin were measured on d 21; while ileal permeability was determined from d 24 to 26. Results indicated that enzyme CSM supplementation increased body weight on d 21 and 35, improved feed to gain ratio from d 0 to 14 and 0 to 21, increased P-glycoprotein dependent efflux permeability (Papp(S–M)), decreased digesta viscosity, and lowered ileal C. perfringens and Lactobacillus colonization. CSM supplementation could also improve feed conversion ratio from d 0 to 35 and VH/CD on d 21 of C. perfringens challenged chicks, while EO supplementation increased villus height and VH/CD. C. perfringens challenge increased intestinal lesion score, C. perfringens and Lactobacillus colonization, but decreased Bifidobacterium colonization and Papp(S–M). C. perfringens challenge also resulted in increased plasma endotoxin, passive transcellular permeability (Papp(M–S)), sIgA, and E. coli colonization when chicks were fed with basal diet, while EO or CSM supplementation could alleviate the alteration caused by C. perfringens infection. In conclusion, dietary enzyme CSM supplementation could benefit for growth performance and gut health, and EO could improve the gut health of C. perfringens challenged chicks.