Research: Mixed results with pro & pre-biotics in broilers

South Korean scientists studied the 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.

A total of 480 mixed sex broilers (BW of 46.3±0.5 g) were randomly assigned to 1 of 4 treatments in a 2×2 factorial arrangement with 2 levels of β-glucan (0 or 1 g/kg) and Bacillus subtilis (0 or 108 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.

Results
Broilers fed Bacillus subtilis diets had 5.3% and 3.3% greater body weight gain (BWG) during d 22-35 and throughout the study, respectively.

No effects were observed in blood profiles. Administration of either β-glucan or Bacillus subtilis increased 3.9% or 3.8% of the relative weight of spleen, respectively, while the supplementation of β-glucan decreased the relative weight of abdominal fat by 16.0%.

Dietary supplementation with β-glucan decreased the breast meat b* value 26.2%, and a synergistic interactive effect of β-glucan and Bacillus subtilis was observed in b* value of breast meat.

Conclusion
Bacillus subtilis at 108 cfu/kg of diet improved BWG and relative weight of spleen, while 1 g/kg β-glucan did not improve BWG, but decreased the relative weight of abdominal fat and b* value of breast meat in broilers.