High fat intake and equine lipid metabolism

Abstract

This thesis deals with the influence of fat feeding on lipid metabolism in horses. Highfat diets have attained considerable interest as a potential tool to improve performance.Many factors affect performance so that large numbers of horses are needed to unequivocally determine the effect of diet on performance. In practice, the execution of trials on diet in relation to performance is not possible. However, based on the reported effects of nutrition on metabolism, it should be possible to predict the effect of nutrition on performance. The aim of the studies described in this thesis was to demonstrate a rationale, or a lack of it, for feeding horses on diets with extra fat. Literature data show that, analogously to training, the contribution of fatty acids to the energy supply during exercise is increased on a fat-rich diet. The fat-induced changes in the metabolic machinery might lead to a sparing of glucose and glycogen during an aerobic workload and to the promoting of glycolysis during anaerobic exercise. Attention was focussed on investigating the effect of dietary fat supplementation on equine lipid metabolism in untrained horses in the fasting state. This thesis shows that feeding a fat-rich diet triggers metabolic adaptations on the cellular level which are comparable to those described as induced by training. Thus, feeding a high-fat diet might be advantagous to exercising horses.