Influences of an essential oil mixture supplementation to corn versus wheat-based practical diets on growth, organ size, intestinal morphology and immune response of male and female broilers

The aim of this study was to investigate the effect of diet type, supplementation diet with an essential oil mixture (EOM), and bird gender on the growth performance, carcass yield, internal organ weight, immune response, and small intestine histology of broiler chickens. To do this, a 2×2×2 factorial arrangement was designed. The variables used were: two diet types (based on either wheat or corn), 2 feed additives (with or without EOM), and gender (male or female). EOM supplementation in the diet decreased body weight in corn-fed male birds at Days 21 and 42, but not in those fed the wheat-based diet, signifying a diet × EOM × gender interaction. Cumulative feed intake was not influenced by either the diet type or EOM. The feed conversion ratio was not affected by diet type, whereas EOM improved feed conversion ratio over the 42-day growth period. Feeding birds on wheat decreased the carcass yield while it increased relative small intestine and large intestine weight. Relative weights of liver, bursa fabricius and serum infectious bursal disease (IBD) and Newcastle disease (ND) titers were not affected by any of the variables studied. EOM supplementation and feeding birds on corn increased jejunal villus height at both 21 and 42 days of age, while bird gender showed no effect. In general, EOM positively influenced body weight gain and efficiency of feed conversion in broiler chickens. Birds receiving the corn-based diet were more efficient in converting feed to body mass as com-pared to those fed on the wheat-based diet.