Anti-coccidial effect of essential oil blends and vitamin D on broiler chickens vaccinated with purified mixture of coccidian oocyst from Eimeria tenella and Eimeria maxima

ABSTRACT A total of 800 1-day-old Ross 308 male broiler chicks were used in a 5-wk feeding trial to evaluate the effects of commercial feed additive that is composed of blends of essential oil (EO; CRINA Poultry, DSM) and vitamin D3. The birds were randomly assigned to 5 treatments with 10 replicate cages; each stocked with 16 birds and was fed corn–soybean-meal-based basal diet. Dietary treatments included: CON, unvaccinated birds fed basal diet/control; CCO, CON + coccidian oocysts vaccinated birds; EOD1, CCO + Essential oil blends and vitamin D/Prototype 1 (50 μg 25-OH-D3/kg diet, 15 mg CRINA Poultry/kg diet); EOD2, CCO + Prototype 2 (69 μg 25-OH-D3/kg diet, 30 mg CRINA Poultry/kg diet); and EOD3, CCO + Prototype 3 (138 μg 25-OH-D3/kg diet, 50 mg CRINA Poultry/kg diet). On day 7, all birds, except CON, were inoculated with 300 to 500 purified sporulated viable oocysts from Eimeria tenella and Eimeria maxima. As a result of this study, the supplementation of EO blends with vitamin D3 showed trends in improvement (P = 0.075) body weight gain (BWG) compared with CON and CCO during the grower phase (day 7 to 21). An increase (P