ORAL WATER-SOLUBLE VITAMIN E SUPPLEMENTATION OF THE MARE IN LATE GESTATION, ITS EFFECTS ON SERUM VITAMIN E LEVELS IN THE PRE- AND POSTPARTUM MARE AND THE NEONATE: A PRELIMINARy INVESTIGATION

Vitamin E, a fat-soluble vitamin, is recognized as an essential nutrient shown to affect equine immune response (Baalsrud and Øvernes, 1986). Few studies have been conducted to examine vitamin E status in the equine beyond those that established the levels in the blood (Schweigert and Gottwald, 1999). Serum vitamin E concentrations are reported to range from 1.6-7.5 μg/ml in normal horses (Butler and Blackmore, 1983). Gay et al. (2004) reported that vitamin E levels (measured as plasma beta tocopherol levels) decreased in mares after foaling (6.05 μg/ml to 5.0 μg/ml). The diffuse epitheliochorial placenta of the equine does not allow fat-soluble vitamins to cross in any appreciable amounts making neonates highly susceptible to vitamin E deficiency. Newborns therefore rely heavily on ingestion of colostrum as a source of vitamin E (Schweigert and Gottwald, 1999). This study examined the effect of oral supplementation of pregnant mares with a water-soluble form of vitamin E (d-alpha tocopherol; Elevate®, KPP) from a natural source during the last two weeks of gestation. The effect of supplementation on serum vitamin E concentrations was investigated in mares prior to foaling and in mares and their foals following birth.