Effect of barley particle size and autolyzed yeast with enzyme on performance, immune system and ileal digestibility of broiler chickens

An experiment was conducted to determine the effects of autolyzed yeast with enzyme supplementation and barley particle size on energy and protein efficiency ratio, immune system and ileal digestibility with 400 one-day-old Ross 308 broiler chickens from both sexes in completely randomized design with factorial arrangement 2×4 with 8 treatments, 5 replicates from 1 to 35 days of age. The experimental treatments included type of additive (without additive, enzyme, autolyzed yeast and autolyzed yeast with enzyme) and barley particle size (fine (2 mm) and coarse (8 mm)). Supplementation of autolyzed yeast and enzyme improved FCR compared to the treatment without additives (P>0.05). Autolyzed yeast with coarse barley particles increased the European efficiency factor, energy and protein efficiency ratio compared to other treatments (P>0.05). Supplementation of enzyme led to a decrease in abdominal fat percentage compared to other treatments (P<0.05). Autolyzed yeast with enzyme increased the length and dry matter percentage of the tibia compared to the treatment without additives (P<0.05). Addition of autolyzed yeast with enzyme improved the response immune system compared to other treatments (P<0.05). Supplementation of autolyzed yeast with enzyme improved the ileal digestibility compared to other treatments (P<0.05). Addition autolyzed yeast alone and with enzyme decreased litter pH compared to the treatment receiving enzyme alone and the treatment without additive (P<0.05). As summary, autolyzed yeast with enzyme can be used to improve the performance of broiler chickens fed diets containing barley.