Effect of hydrolysed yeast (Saccharomyces cerevisiae) product (ProgutTM) on the microbial flora of the horse

Prebiotics can be used in equine nutrition as balancing factors in stressful situations. In this research we studied the effect of hydrolysed yeast product (ProgutTM) on the microbial flora of a horse as determined in faeces. ProgutTM is hydrolysed yeast product manufactured from brewer s yeast (Saccharomyces cerevisiae). Ten Finnhorse mares were fed basal diet of hay and oats for three weeks before first microbial samples were taken. After the first samples, yeast hydrolysate was added on the diet and after feeding period of another three weeks the second microbial sample was taken. Aerobic and anaerobic total bacteria, enterobacteria, Lactobacillus, lactate producing bacteria, bifidobacteria and Bacteroides- prevotella were determined from faeces. Volatile fatty acids (VFA) and pH were also determined. The total count of aerobic bacteria declined after the addition of the yeast product. The enterobacteria and Bacteroides-prevotella -group increased and bifidobacteria decreased. No change was observed in total anaerobic bacteria, lactic acid bacteria or Lactobacillus. VFAs were more homogenous between animals after yeast product addition.vo