by Kentucky Equine Research Staff
Hops, the female flowers of the hop plant (Humulus lupulus), are best known for their role in the production of beer. The flowers add a bitter taste to the brew, and the natural antibacterial action of hops favors the activity of yeast. This antibacterial quality may help to prevent pasture-associated laminitis, according to the results of a study conducted by researchers from the University of Kentucky.
Horses who consume too much fresh pasture grass ingest high levels of fructans, carbohydrates that are not processed in the equine small intestine and thus can pass to the hindgut. These sugars enhance the growth of certain hindgut bacteria including Streptococcus bovis. This bacterial strain enhances fermentation that can lead to an overproduction of lactic acid, a shift in hindgut pH, and finally the inflammatory reactions that lead to laminitis.
In the laboratory study, the hops-derived beta-acid lupulone was added to equine fecal microorganisms. Lupulone decreased intracellular potassium in S. bovis bacteria, reducing the number of these fructan-fermenting microbes. This change led to lower total lactate production and minimized pH changes.
While the results of this study may eventually lead to products that could be administered to horses particularly sensitive to fructans, much more research is necessary before such products could be developed. For the foreseeable future, horse owners should rely on known methods of limiting fructan consumption. These include restricted grazing times, use of dry lots and grazing muzzles, and watching all pastured horses for any sign of hoof pain during periods of lush forage growth.
Reprinted with permission of Kentucky Equine Research. For more information on horse nutrition and health, visit www.ker.com. Save 10 % on all KERx products at shop.kerx.com using prom code HOLISTIC.