Eicher S D, Morrill J L, Blecha F, Chitko-McKown C G, Anderson N V, Higgins J J
Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-1600.
J Dairy Sci. 1994 May;77(5):1399-407. doi: 10.3168/jds.S0022-0302(94)77078-8.
Holstein calves (n = 44) were fed milk replacers from d 3 to 45 with low or high concentrations of vitamin A (7000 or 87,000 IU/kg) and vitamin E (11.2 or 57 IU/kg) to examine the influence of vitamin concentrations on vitamin bioavailability and leukocyte functions. Concentrations of alpha-tocopherol in plasma reflected increased vitamin E but were unaffected by increased vitamin A. Plasma retinol concentrations were greatest with high supplementation of vitamins A and E at wk 3; however, at wk 6, plasma of calves fed high vitamin A and low vitamin E contained the most retinol. Increased supplementation of vitamin A improved fecal consistency compared with that for calves fed the low vitamin A diet at wk 3 and 4. At wk 3, calves that received increased supplementation of vitamins E and A had enhanced neutrophil bactericidal activity compared with that of calves with increased individual vitamins. Lymphocyte DNA synthesis and chemotactic index were unaffected by dietary treatments. Results indicate that increased vitamin A in milk replacer did not affect plasma vitamin E concentrations, benefited fecal scores regardless of vitamin E concentrations, but was only beneficial to bactericidal activity of neutrophils in conjunction with increased vitamin E.
选用44头荷斯坦犊牛，从第3天至第45天给它们饲喂维生素A（7000或87,000国际单位/千克）和维生素E（11.2或57国际单位/千克）浓度低或高的代乳粉，以研究维生素浓度对维生素生物利用率和白细胞功能的影响。血浆中α-生育酚的浓度反映出维生素E含量增加，但不受维生素A增加的影响。在第3周时，高剂量补充维生素A和E时血浆视黄醇浓度最高；然而，在第6周时，饲喂高维生素A和低维生素E的犊牛血浆中视黄醇含量最多。与在第3周和第4周饲喂低维生素A日粮的犊牛相比，增加维生素A的补充可改善粪便稠度。在第3周时，与单独增加一种维生素的犊牛相比，同时增加维生素E和A补充量的犊牛中性粒细胞杀菌活性增强。淋巴细胞DNA合成和趋化指数不受日粮处理的影响。结果表明，代乳粉中维生素A增加不影响血浆维生素E浓度，无论维生素E浓度如何均有利于粪便评分，但仅在维生素E增加的情况下才有利于中性粒细胞的杀菌活性。
