THE EFFECT OF HAY TYPE AND SOAKING ON GLYCEMIC RESPONSE IN HORSES

Abstract

Dietary management of equine metabolic syndrome includes minimizing glycemic response. Soaking hay prior to feeding reduces nonstructural carbohydrate content, but little research indicates if soaking hay reduces glycemic response. Glycemic response of four hay diets were evaluated: dry or soaked prairiegrass hay, and dry or soaked alfalfa hay. Twelve healthy horses were randomly assigned into two groups and fed the hay diets at 0.5% BW in a 2x2 factorial design. Blood samples were collected at 0, 30, 60, 90, 120, 180, 240, and 300 min after feeding. Plasma glucose was analyzed using a colorimetric assay, and incremental area under the curve (AUC) of glucose response calculated. Data were analyzed using a mixed model with repeated measures. Plasma glucose and the AUC was higher (P =0.0001) in healthy horses fed alfalfa compared to grass hay, with no differences identified due to soaking (P = 0.82). Additional research is needed to determine if soaking hay has physiological merit in horses with metabolic issues.