An evaluation of a yeast-derived mannan oligosaccharide and its mode of action in swine.

摘要

Bio-MosRTM (Alltech, Inc., Nicholasville, KY) is a mannan oligosaccharide product, derived from the outer cell wall of the yeast Saccharomyces cerevisiae, with a theorized mode of action regarding the association of its mannan component with microbes expressing mannose-sensitive type-1 fimbriae. In theory, microbes that may bind to Bio-MosRTM are flushed from the gastrointestinal tract due to the inability of digestive enzymes to hydrolyze Bio-Mos RTM. In a meta-analysis of 54 comparisons of nursery pigs fed Bio-Mos RTM versus no Bio-MosRTM, there was an overall 4.12% improvement in growth rate with a more pronounced response (4.60%; P 0.05) to Bio-MosRTM seen in pigs with a slow growth rate during the first 1--2 weeks post-wean. A 2 x 2 factorial experiment was conducted to compare the effect of Bio-MosRTM to an antimicrobial (carbadox) on gastrointestinal characteristics and microbiota of nursery pigs. Bio-MosRTM decreased the pH of various gastrointestinal segments but this depended on the presence/absence of carbadox. Carbadox and Bio-Mos RTM increased the size of duodenal villi at 1 and 3 weeks post-wean, respectively. Microbiota analysis by 16S rDNA PCR-DGGE revealed that carbadox and Bio-MosRTM made pigs more similar to each other by 1 and 3 weeks post-wean, respectively. Both in vitro and in vivo analysis of the effect of gastrointestinal environments on percent disappearance of Bio-MosRTM demonstrated that Bio-Mos RTM may be hydrolyzed by digestive enzymes but a significant percentage is able to survive the simulated environments and passage through the gastrointestinal tract of nursery pigs. Exposure of Bio-MosRTM to an in vivo rumen environment revealed that components which are removed through upper gastrointestinal tract exposure may be the same as those lost during fermentation. Utilizing the mobile nylon bag technique in ilealcannulated pigs, nylon bags containing Bio-MosRTM or a glucan-rich fraction were analyzed following passage through the lower intestinal tract. Bio-Mos RTM had a higher concentration (P 0.05) of Enterobacter spp., known to express type-1 fimbriae, but an overall lower number of total microbial counts. An overall summary of this research indicates that Bio-MosRTM has the potential to be an acceptable growth promoter by altering gastrointestinal characteristics and microbiota in nursery pigs.