Effects of β-glucan and Bacillus subtilis on growth performance, blood profiles, relative organ weight and meat quality in broilers fed maize-soybean meal based diets

This study was conducted to determine effects of dietary supplementation of beta-glucan and Bacillus subtilis on growth performance, blood profiles, relative organ weight, and meat quality in broilers fed maize-soybean meal based diets. A total of 480 mixed sex broilers (BW of 46.3 +/- 0.5 g) were randomly assigned to 1 of 4 treatments in a 2 x 2 factorial arrangement with 2 levels of beta-glucan (0 or 1 g/kg) and Bacillus subtilis (0 or 10(8) cfu/kg). There were 6 replicate pens/treatment with 20 chicks/pen for growth performance and 5 chicks/pen for meat quality and blood profiles in this 5-wk study. Broilers fed Bacillus subtilis diets had 5.3% and 3.3% greater (P < 0.05) body weight gain (BWG) during d 22-35 and throughout the study, respectively. No effects were observed in blood profiles. Administration of either beta-glucan or Bacillus subtilis increased (P < 0.05) 3.9% or 3.8% of the relative weight of spleen, respectively, while the supplementation of beta-glucan decreased (P < 0.05) the relative weight of abdominal fat by 16.0%. Dietary supplementation with beta-glucan decreased the breast meat b* value 26.2% (P < 0.05), and a synergistic interactive effect of beta-glucan and Bacillus subtilis was observed (P < 0.05) in b* value of breast meat. In conclusion, Bacillus subtilis at 10(8) cfu/kg of diet improved BWG and relative weight of spleen, while 1 g/kg beta-glucan did not improve BWG but decreased the relative weight of abdominal fat and b* value of breast meat in broilers. (C) 2012 Published by Elsevier B.V.