title: Effect of parturition on levels of vitamins A and E and of beta-carotene in plasma and milk of mares.
abstract: The objective of this study was to investigate in mares the effect of parturition on plasma and milk levels of retinol, beta-carotene, alpha-tocopherol and cholesterol over 12 weeks around parturition. In blood plasma of horses around parturition an increase of all these components was observed. This increase was most impressive in beta-carotene (P<0.05) and less pronounced for vitamin E, vitamin A and cholesterol. The magnitude of increase around parturition corresponded well with the magnitude of accumulation in colostrum; levels of beta-carotene in colostrum were 65 times higher compared to mature milk while vitamin A, vitamin E and cholesterol were only 3 to 8 times higher. Beta-carotene concentrations in colostrum were positively correlated with corresponding plasma levels (r = 0.9; P<0.001). Reasons for the increase in plasma beta-carotene around parturition may include an improved absorption of carotene and/or reduced conversion into vitamin A as well as mobilisation from tissue storages or a reduced uptake in tissues other than the mammary gland. In conclusion, the results may point to possible component- and species-specific differences involved in the transfer of fat-soluble vitamins, beta-carotene and cholesterol from blood plasma into colostrum.
authors.affiliation: Institute of Nutritional Science, University of Potsdam, Bergholz-Rehbrücke, Germany.
authors.forename: F J
authors.initials: FJ
authors.lastname: Schweigert
authors.forename: C
authors.initials: C
authors.lastname: Gottwald
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000097:blood / Q000378:metabolism; D003126:Colostrum / Q000737:chemistry; D005260:Female; D006736:Horses / Q000097:blood / Q000378:metabolism*; D007743:Labor, Obstetric / Q000097:blood / Q000378:metabolism*; D008297:Male; D008892:Milk / Q000737:chemistry*; D011247:Pregnancy; D012016:Reference Values; D014801:Vitamin A / Q000097:blood / Q000378:metabolism*; D014810:Vitamin E / Q000097:blood / Q000378:metabolism*; D019207:beta Carotene / Q000097:blood / Q000378:metabolism*
chemical_list: D019207:beta Carotene; D014801:Vitamin A; D014810:Vitamin E; D002784:Cholesterol