The Effect of Different Feed Delivery Methods on Time to Consume Feed and the Resulting Changes in Postprandial Metabolite Concentrations in Horses by Jenna
KUTZNER-MULLIGAN, JENNA MARIE GILCHRIST. The Effect of Different Feed Delivery Methods on Time to Consume Feed and the Resulting Changes in Post-prandial Metabolite Concentrations in Horses. (Under the direction of Dr. Shannon Pratt-Phillips.) Management techniques that reduce the insulin response to feeding in horses have application in preventing insulin resistance (IR) and potential associations (e. g., laminitis). Eight mature idle horses of BCS between 5 and 6.5 and with no previous indication of IR were fed a meal of concentrate feed under 4 feed delivery treatments in a repeated Latin Square design. Treatments were all based on a bucket of equal dimensions. The treatments included a control (CON) and 3 treatments hypothesized to increase time to consume feed (TIMEfeed): mobile obstacles above the feed (BALL), stationary obstacles below the feed (WAFF), and feed with water added (WTR). Jugular venous blood samples were taken at feed delivery, every 10 min for the first hour, and then every 30 min until 300 min post feed delivery. TIMEfeed was greater (P = 0.004) for BALL and WAFF when compared to CON and WTR. Compared to CON and WTR, average glucose and insulin concentrations tended to decrease due to BALL (P = 0.059) and WAFF (P = 0.072) and the peak glucose concentration was decreased (P = 0.049). Compared to all other treatments, peak insulin concentrations (P = 0.030) and area under the curve of insulin (P = 0.051) were decreased and time to peak insulin was increased (P = 0.031) due to BALL. Therefore, feed delivery methods that include obstacles effectively increase TIMEfeed and attenuate post-prandial glucose and insulin parameters. A second experiment was designed to determine if the TIMEfeed changes associated with BALL and WAFF in Exp. 1 remain effective over 4-d periods. Four horses with no recent or regular history of consuming meals were fed concentrate meals for 4 consecutive days using the same treatments described in Exp. 1 under a Latin Square design. Horses were subject to a 4-d adaptation period (ADP) and were randomly assigned to 4-d treatment periods using the 4 previously described treatments. During ADP, TIMEfeed decreased (P = 0.018). However, following adaptation, TIMEfeed did not decrease significantly over 4 days of any treatment feed delivery method, but BALL and WAFF had higher TIMEfeed when compared to CON and WTR (P < 0.001) and maintained prolonged TIMEfeed after 4 d of use (P = 0.006). Utilizing obstacles to increase TIMEfeed on a daily basis may be an effective method to reduce post-prandial glucose and insulin concentrations, thereby decreasing the risk of insulin resistance development in horses The Effect of Different Feed Delivery Methods on Time to Consume Feed and the Resulting Changes in Post-prandial Metabolite Concentrations in Horses by Jenna Marie Gilchrist Kutzner-Mulligan A thesis submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the requirements for the Degree of Master of Science