Retinol, β-carotene and β-tocopherol concentrations in mare and foal plasma and in colostrum |
| |
| Authors: | L S Gay D S Kronfeld PhD DSc MVSc A Grimsley-Cook DVM MS J J Dascanio DVM A O Ordakowski-Burk PhD R K Splan PhD E A Dunnington PhD D J Sklan PhD |
| |
| Institution: | a Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, USA;b Department of Large Animal Clinical Sciences, VMRCVM, USA;c Department of Animal and Avian Sciences, University of Maryland, College Park, USA;d Department of Animal Sciences, Hebrew University, Rehovot, Israel |
| |
| Abstract: | Fat-soluble vitamins transfer poorly across the diffuse epitheliochorial placenta of the mare, so the neonatal foal is dependent on its supply via colostrum. Concentrations of retinol (RT), β-carotene (BC), and β-tocopherol (AT) were assayed in samples of plasma, colostrum and milk from nine mares of mixed light breeding and their foals at parturition and days 1, 2, and 4 postpartum. Samples were analyzed simultaneously for RT, BC, and AT using a new, less time-consuming reverse phase high-pressure liquid chromatography (HPLC) method. Feeds were analyzed, and mean daily intakes calculated. Mare plasma RT increased from day 1 to day 4 (P = .033), and plasma AT declined linearly from day 0 to day 4 (P = .006). Colostrum concentrations of all vitamins increased from parturition to day 1, and then declined rapidly over the 4 days. Foal plasma BC increased from parturition to day 4 (P = .080), and plasma AT increased from parturition to day 2 (P < .001), and 4 (P = .060). These observations suggest that three times the current recommendation of vitamin A is sufficient for pregnant mares, in keeping with previous studies of growth, pregnancy, and lactation. In contrast, the linear decrease in mare plasma AT suggests that 1.2 times the current recommendation of vitamin E may be less than optimal for pregnant mares.IntroductionThe diffuse epitheliochorial placenta of the mare does not allow fat-soluble vitamins to cross with ease to the fetus,1] so their status in the neonatal foal is dependent on colostrum. This first milk contains these vitamins, which are necessary for many functions.Vitamin A is required for vision, reproduction, growth, development, and maintenance of epithelial cells, and osteoclast activity in bone formation. In addition, vitamin A deficiencies reduce resistance to disease, can cause neurological degeneration, and congenital defects.2] Vitamin E, an antioxidant, prevents lipid peroxidation and cell membrane damage. Its deficiency in horses has been associated with a form of muscular dystrophy and impaired immune function. 3]Studies on the mare and foal have described blood concentrations of one or two of these vitamins,4, 5 and 6] but only one involved all three. 7] In that study, vitamin concentrations were assayed in mare blood and milk, but only once in foal blood at parturition, so data during the periparturant period is incomplete.The objectives of this enumerative study were to determine concentrations of RT, BC, AT in plasma and colostrum, to evaluate colostral transfer of these vitamins, to assess the adequacy of vitamin intakes of mares, and to develop a time-saving single-run HPLC method.Materials and methodsAnimalsNine healthy aged multiparous mares of mixed light breeding (13.6 ± 1.5 years, 592 ± 20 kg body mass) and their foals were sampled. The institutional animal care and use committee approved the protocol. Mares were kept on meager late-winter mixed grass pasture, with free access to round bale orchard and fescue grass hay, water, and trace mineral/vitamin salt. They were fed 2 kg of concentrate twice daily at 7:00
and 3:00
. The diet met or exceeded current recommendations for pregnant mares at 11 months gestation for energy.8] Samples of hay and concentrate were submitted for partial proximate analysis to the Virginia Tech Forage Testing Laboratory where standard AOAC 9] methods are used ( Table 1). Samples of feeds were also taken for analysis of RT, BC, and AT ( Table 2). |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
