Texas Equine Veterinary Association

www.teva-online.org • Page 7 the use of prebiotics used in conjunction with probiotics to create symbiotic preparations. However, the difference in research results may be attributed to variation in diet and the prebiotic/probiotic preparations used. Jouany et al. (2008) observed that yeast culture supplementation positively influenced ADF apparent digestibility regardless of diet with similar results observed in both high starch and high fiber diets. When probiotics were fed in conjunction with high starch diets, researchers observed maintenance of cecal pH, decreased concentrations of lactic acid, and enhanced populations of cellulolytic bacteria which supported fibrolytic activity (Moore et al., 1994). In contrast, live yeast culture supplementation also supported cellulolytic bacteria and fibrolytic activity when high fiber diets were offered (Medina et al., 2002). Similar results were observed when yeast culture prebiotic was supplemented with diets of varying forage quality. The prebiotic improved digestibility of dry matter, crude protein, neutral detergent fiber (NDF), and hemicellulose when offered in conjunction with lower quality forage. Prebiotic supplementation also reduced disruptions in colonic microbial populations after an abrupt change in diet. This was evidenced by reduction in E. coli numbers while other populations remained similar (Respondek et al., 2008). While research evidence using these digestive aids is highly variable, it seems to be beneficial when diets consist of high starch or contain forage quality that is less than ideal. These diets may contribute to undesirable conditions in the microbial ecosystem. Furthermore, these products may be most useful when normal microbial populations are disrupted. The presence of pathogenic organisms or prolonged oral antibiotic use may warrant supplementation with prebiotics and probiotics. Situations in which horses may benefit from these types of products include hard keepers, geriatrics, horses with chronic diarrhea, recurrent colic cases, horses under stress, and horses recovering from surgery and/or other veterinary procedures. Disruption of the hindgut microflora is common with dietary change and medical treatment. The use of prebiotic, probiotic, and/or symbiotic preparations may help this disruption and improve digestibility and ultimately health of the horse. These products many be extremely beneficial under certain conditions, but may have little effect in the mature, healthy horse. However, many horse owners are finding this a safe and economical way to improve gastrointestinal health. references Jouany, J. P., J. Gobert, B. Medina, G. Bertin, and V. Julliand. 2008. Effect of live yeast culture supplementation on apparent digestibility and rate of passage in horses fed high fiber or high starch diet. J. Anim. Sci. 86:339-347. Medina, B., Girard, I. D., Jacotot, E. &Julliand, V. 2002. Effect of a preparation of Saccharomyces cerevisiae on microbial profiles and fermentation patterns in the large intestine of horses fed a high fiber or a high starch diet. J. Anim. Sci. 80:2600–2609. Moore, B. E., K. E. Newman, P. Spring and V. E. Chandler. 1994. Effect of yeast culture (Yea Sacc1026) on microbial populations and digestion in the cecum and colon of the equine. J. Anim. Sci. 72 (Suppl 1):252 (Abstr.). Potter, G. D., F. F. Arnold, D. D. Householder. 1992. Digestion of starch in the large or small intestine of the equine. Physiologie und Pathologie des Verdauungskanals-Konsequenzen fur dicErnahrung 107-111. Respondek, F., A. G. Goachet, and V. Julliand. 2008. Effects of dietary short-chain fructooligosaccharides on the intestinal microflora of horses subjected to a sudden change in diet. J. Anim. Sci. 86:316-323.

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