Try Supplementing Yeast When Changing a Horse's Diet
Abrupt diet changes can affect the beneficial microbial population in horses’ hindguts and increase their risk of developing colic and laminitis. Sometimes, however, it’s not possible for owners to make diet changes gradually, as is recommended by equine nutritionists and veterinarians. A researcher in Scotland recently confirmed it might be appropriate to provide a particular supplement to ease the transition in these cases.

Anna Garber, a postgraduate student at the University of Glasgow’s School of Veterinary Medicine,  evaluated whether a yeast supplement would help mitigate the risks associated with sudden diet changes. She shared her findings at the 2019 Equine Science Society Symposium, held June 3-6 in Asheville, North Carolina.

“Most owners change horses’ diets from pasture to conserved forage and vice versa twice a year,” when going in and out of winter, Garber said. So she studied this specific scenario.

Garber switched eight mature ponies that had been maintained on grass pasture to free-choice hay. Four of the ponies received a yeast supplement (Gut Balancer) and four served as controls. After 14 days Garber switched all the ponies back to full-time grass, and 14 days later back to hay. Meanwhile, she collected fecal samples from the ponies after each diet change and analyzed the diversity of the microbiota DNA within.

Upon analyzing her results, Garber found that supplemented ponies had higher levels of Bacteroidetes (the most abundant phylum, which has been known to decrease after abrupt diet changes, she said) than control ponies. This translates to a more stable microbial environment, she said. “And, as we know with horses, stable is better.”