Influence of Supplemental Levels of Probiotic on Growth Response, Intestinal Microbiota and Carcass Characteristics of Broilers

Abstract

The effect of varying levels of commercial probiotic on the performance, microbial status and carcass quality of broiler chickens was investigated in a 42-day experiment between March and April, 2014. Two hundred (200) one-day-old broiler chickens were randomly allotted to 4 diets with 5 replicates of 10 birds each in a completely randomized design. Diet 1 was the basal diet with no supplement while diets 2, 3 and 4 were basal diets supplemented with graded levels (200, 400, 600 mg/kg) of probiotic. On day 42, ileal digesta were collected for microbial count and intestinal pH. The weight of carcass primal cuts and visceral organs were also recorded. There were no remarkable differences observed in the final weight, weight gain and feed conversion ratio of the birds on the experimental diets in both starter and finisher phases. However, significantly higher (P= .05) feed intake (550.00 g/bird) was recorded in birds on diet supplemented with 600 mg/kg probiotics while birds on the basal diet had the least (470.00 g/bird) at day 0-21. Meanwhile between 22-42 days, the highest feed intake (1821.25 g/bird) was recorded for birds on diet supplemented with 400 mg/kg probiotic while the least (1630.00 g/bird) was observed in birds fed basal diet. There were no appreciable differences observed in the microbial population in the GIT of birds on the experimental diet except in the gram negative Enterococcus and Lactic Acid Bacteria counts. Birds on 600 mg/kg probiotic dietary supplement had the highest live weight (2142.00 g/bird) which was similar to those on 200 mg/kg and 400 mg/kg probiotics. There were no significant differences recorded for visceral organs and weight of the primal cuts of birds on the experimental diets except for drumstick. In conclusion, improved growth response and carcass quality were achieved at all the inclusion levels of dietary probiotic without compromising birds’ performance.