The effect of exercise on the immune system, and compensation by the administration of vitamins, in horses

Horses subjected to sporting activities have a reduced activity of the immu ne system as assessed by the increased secretion of cortisol. During runnin g, the formation of oxygen-radicals and of decay products of lipid-peroxyl compounds increases. Greater intakes of green fodder are associated with in creased supplies of beta-carotene, most B vitamins, ascorbic acid, vitamins E and K. In cases where there is a small or no intake of green fodder, a d aily supplementation comprising 60,000 I.E. of vitamin A, 5 - 10 g ascorbic acid and 1 - 2 g vitamin E is recommended for horses, of 500 kg bodyweight , subjected to athletic activities. This treatment is also indicated when h orses are subject to stress, for example when they are transported, when th ey are moved and when they are lame.