Effects of herbal growth promoters and prebiotic( lactose) on performance, carcass characteristics and small intestinal morphology of broiler chickens

An experiment was conducted to evaluate the effects of ASRI1, ASRI2, commercial growth promoter and prebiotic on performance, carcass characteristics and small intestinal morphology of broiler chickens. A total number of 875 day-old Ross 308 chickens were used in a completely randomized designed as a 2×3 factorial with six treatments, five replicates of 25 birds per each. Chickens were fed with three types of growth promoter (ASRI1, ASRI2 and commercial growth promoter) and two levels of prebiotic (0 and 1 kg/ton of diet). Body weight, feed intake and feed conversion ratio were not affected by herbal growth promoter and prebiotic (p>0.05). Effects of growth promoters and prebiotics on carcass characteristics were not significates, but prebiotic reduced the carcass yield (p < 0.05). Relative weights and lengths of intestinal tracts and morphological indices were not affected by growth promoter and prebiotic. Finally, based on the results of this research, commercial growth promoters could be substituted by ASRI1 and ASRI2.