Dietary Energy Source Affects Glucose Kinetics 2008

The type of feed the horse eats is what determines what fuel is available for the horse to use during exercise. So it is important to figure out the optimal diet for your horses. Although there has been research showing the benefits of fat supplementation over feeding grain in equine diets, many people still prefer to add grain to the diet thinking it is better for their horses. This paper is one of the more recent showing that fat supplemented horses used less glucose during endurance exercise than the horses whose diet was supplemented with sweet feed. That means that that their limited glycogen stores are used up faster than when they are fed the higher fat diet. So, it is the horses fed higher fat without the grain whose energy systems will benefit in endurance exercise. And on top of what to feed for best performance is that the traditional high grain diet may be a root cause of many problems, including laminitis, obesity, diabetes and tying up.

Dietary Energy Source Affects Glucose Kinetics in Trained Arabian Geldings at Rest and during Endurance Exercise Kibby H. Treiber,3* Ray J. Geor,3 Raymond C. Boston,4 Tanja M. Hess,3 Pat A. Harris,5 and David S. Kronfeld3 3 Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061; 4 Department of Clinical Sciences, New Bolton Center, Kennett Square, PA 19348; and 5 Equine Studies Group, WALTHAM Centre for Pet Nutrition, LE14 4RT Melton Mowbray, UK J. Nutr. 138: 964–970, 2008 Abstract

Advances in modeling and tracer techniques provide new perspective into glucose utilization and potential consequences to health or exercise performance. This study used stable isotope and compartmental modeling to evaluate how adaptation to a feed high in sugar and starch (SS) compared with a feed high in fat and fiber (FF) affects glucose kinetics at rest and during exercise in horses. Six trained Arabians adapted to each feed underwent similar tests at rest and while running ;4 m/s on a treadmill. For both tests, horses received 100 mmol/kg body weight [6,6-2H]glucose through a venous catheter. Circulating tracer glucose was described for 150 min by exponential decay curves and compartmental analysis. All parameters of glucose transfer increased with exercise (P # 0.004). Compared with FF horses, SS horses had higher circulating glucose (P ¼ 0.022) and fractional glucose transfer rates (min 21 ) at rest (P ¼ 0.055). Exercise increased glucose irreversible loss (mmol/min) more in SS horses (P ¼ 0.037). Total glucose transfer during exercise tended to be greater in SS horses (0.027 6 0.002 mmol/min) compared with FF horses (0.023 6 0.002 mmol/min) (P ¼ 0.109). This study characterized the effect of diet on glucose kinetics in resting and exercising horses using new modeling methods. Horses adapted to a fat-supplemented feed utilized less glucose during low-intensity exercise. Fat supplementation in horses may therefore promote greater flexibility in the selection of substrate to meet energy demands for optimal health and performance.