Stowe H D
J Anim Sci. 1982 Jan;54(1):76-81. doi: 10.2527/jas1982.54176x.
Serum and milk samples from mares and serum samples from their foals were taken at parturition and on d 1, 2, 4, 7, 14 and 21 postpartum. The samples were assayed for retinyl (r.) palmitate, r. acetate and retinol by high performance liquid chromatography. Peak vitamin A activity in milk occurred 1 d postpartum and preceded by 3 d the maximum vitamin A activity in foal serum and the lowest vitamin A activity in the mare serum. Mare serum contained approximately a 65:35 ratio of retinol:r. palmitate and less than 1% r. acetate. Retinyl palmitate was the predominant form of vitamin A in milk until 2 to 3 d postpartum, when r. acetate became and remained the predominant form. Retinol represented less than 1% of the milk vitamin A. A significant quantity of r. acetate was present in the foal sera at 4 d of age, but thereafter serum r. acetate appeared unaffected by the increasing r. acetate levels in the mare milk.
在分娩时以及产后第1、2、4、7、14和21天采集母马的血清和乳汁样本以及它们驹儿的血清样本。通过高效液相色谱法测定样本中的视黄醇棕榈酸酯、视黄醇醋酸酯和视黄醇。乳汁中维生素A活性峰值出现在产后1天，比驹儿血清中最大维生素A活性以及母马血清中最低维生素A活性提前3天出现。母马血清中视黄醇与视黄醇棕榈酸酯的比例约为65:35，视黄醇醋酸酯含量不到1%。产后2至3天之前，视黄醇棕榈酸酯是乳汁中维生素A的主要形式，之后视黄醇醋酸酯成为并一直是主要形式。视黄醇在乳汁维生素A中所占比例不到1%。驹儿4日龄时血清中存在大量视黄醇醋酸酯，但此后血清视黄醇醋酸酯似乎不受母马乳汁中视黄醇醋酸酯水平升高的影响。
