effect of fat source and additive type on performance, productive traits and gut morphology of broiler chickens

the present study was carried out to evaluate the effects of vegetable fat sources and additives on performance and morphological parameters of the small intestine of arain broiler chickens. birds were randomly used in a 2×3 factorial arrangement of dietary treatments included two fat sources (canola or pumpkin seed) and three additives (without additive, 0.1 g/kg probiotic and 0.15 g/kg virginamycin) with four pen replicates and 20 birds per each. the growth performance and productive traits, with using of neither additives nor fat sources or fat sources × additives were unaffected. however, probiotic was significantly decreased crypt depth and increased villi height to crypt depth ratio in jejunum and ileum (p