Effect of Concentrate Starch and Soluble Fiber Level on Glucose and Insulin Responses in Horses
Starch and sugar in the horse’s diet can cause an increase in blood glucose (called a glycemic response), which causes an increase in blood insulin. High blood insulin concentrations or insulin resistance has been implicated in the development of equine health problems such as laminitis, Equine Cushing’s Disease and Equine Metabolic Syndrome. Also, high blood levels of glucose and insulin have been associated with excitability in the horse. Currently, there is little evidence addressing the level of starch and/or sugar to prevent a large glycemic response in the horse and if the level of soluble fiber in the diet will affect blood glucose and insulin levels.
A CRF research study was conducted at the University of Kentucky and eight mature horses were used to evaluate the effect of starch and soluble fiber levels in the concentrate or grain portion of the diet on the horse’s blood glucose and insulin levels. The four pelleted concentrate treatments were High Starch/Low Soluble Fiber Treatment 1 (27.6% starch and 6.7% soluble fiber), High Starch/High Soluble Fiber Treatment 2 (28.70% starch and 13.30% soluble fiber), Low Starch/Low Soluble Fiber Treatment 3 (16.30% starch and 11.2% soluble fiber) and Low Starch/High Soluble Fiber Treatment 4 (17.50% starch and 13.80% soluble fiber). Each horse received each concentrate feed in a random sequence. Horses were fed these pelleted feeds and alfalfa cubes two times daily and the amounts of feed and hay were adjusted to maintain a constant body weight. Blood samples were taken and blood glucose and insulin concentrations were determined.
The results of this study demonstrate that blood glucose and insulin levels were significantly reduced after feeding when horses received the low starch (16-17% starch) pelleted feeds compared to the high starch (27-28% starch) pelleted feeds (Graphs 1 and 2). There were no significant effects of soluble fiber level on blood glucose or insulin.
What Does This Mean for Horse Owners?
Cooperative Research Farms (CRF) is actively involved in equine nutrition research to develop safer and more effective feeds for your horses. This research study shows that horse feeds should contain less than 18% starch to reduce high blood glucose and insulin responses. A feed with less than 18% starch would be recommended for horses that exhibit excitable behavior after feeding, that are prone to laminitis, or that have insulin resistance due to Equine Cushing’s Disease and Equine Metabolic Syndrome. CRF members have developed low starch feeds in accordance with this research and the one nearest to you can be located by going to the CRF web site at www.crfarms.org.
Horse feeds available from Southern States with less than 18% starch include: Triple Crown® Growth, Triple Crown® Complete, Triple Crown® Senior, Triple Crown® Low Starch, Triple Crown® Training Formula, Triple Crown® Lite, Legends® Racing, Legends® Maturity, Legends® Mare & Foal (pelleted and textured formulas) and Legends® Performance (pelleted formula only).