Effects of dietary supplementation with Bacillus subtilis and yeast culture on growth performance, nutrient digestibility, serum indices and faeces microbiota of weaned piglets

The aim of this study was to investigate the effects of Bacillus subtilis and yeast culture (YC) on growth performance, nutrient digestibility, serum biochemical and immunological parameters and microbial community of weaned pigs. One hundred and ninety-two weaned piglets (Large White x Landrace, 96 males and 96 females) with an average initial body weight of 8.22 +/- 1.46 kg were randomly divided into 4 groups (8 piglets per pen, 6 pens per group). Piglets in the control group were fed a basal diet with 1 g/kg of bacitracin zinc and the others were fed basal diets supplemented with 1 g/kg of solid-state products containing 10(10) CFU/g of B. subtilis or 3 g/kg of YC with live yeast (Saccharomyces cerevisiae) cells of 4.5 x 10(6) CFU/g or the combination of two above mentioned supplements. Pigs were fed the experimental diets for 41 days. There was no significant difference in body weight and feed intake of piglets between control and other experimental groups. In comparison to the control group, the ether extract digestibility was increased in all supplemented group, and the P digestibility was decreased only in B. subtilis group. The supplementation with B. subtilis and/or YC did not affect either serum biochemical or immunological parameters in comparison to the control group. Also, the similar effect on faecal microbiota composition was stated in the supplemented groups and control one. B. subtilis or YC could be used as a substitute for antibiotics and so be applied to the rearing of weaned piglets. However, the usage of their combination in the examined proportion does not enhance the effect.