Asadian A, Mézes M, Mirhadi S A
Department of Nutrition, University of Agricultural Sciences, Gödöllö, Hungary.
Acta Vet Hung. 1996;44(1):99-109.
Ninety ram lambs of three Iranian fat-tailed sheep breeds including the Shal breed (age: 4-6 months) in one experiment and the Sanjabi and Bakhtiari breeds (6-9 months) in another experiment were assigned to five groups of 5-7 lambs each to receive a basal diet plus different levels of vitamins A and E supplementation. The groups received 0, 50 or 100 IU vitamin A/kg body mass (b.m.) and 0, 15 or 30 IU vitamin E/kg of diet. In the vitamin A groups a constant level of 15 IU vitamin E and in the vitamin E groups a constant level of 50 IU vitamin A supplementation was provided. Blood plasma samples were taken at the beginning and at the end of the experiments and the concentrations of vitamins A and E were determined by high-performance liquid chromatography (HPLC). Vitamin A supplementation of the highest level (100 IU/kg b.m.) significantly increased the retinol content of the blood plasma in the Shal (P < 0.01) and Bakhtiari (P < 0.05) breeds. The mild increase of retinol concentration in the Sanjabi breed was not significant (P > 0.05). Vitamin A supplementation greatly decreased the alpha-tocopherol content of the blood plasma in all three breeds (P < 0.01). It increased the average daily body mass gain of lambs of the Shal breed (P < 0.01) but decreased that of Bakhtiari lambs (P < 0.05). Supplementation of vitamin E mildly decreased the retinol content of the blood plasma in all the breeds and the decrease was statistically significant (P < 0.05) for the Shal breed at the highest dose level. Vitamin E supplementation greatly increased the alpha-tocopherol concentration of the blood plasma in all the breeds (P < 0.01-0.001). It decreased the average daily body mass gain of the Shal breed (P < 0.001) but improved it in the two other breeds. That increase was statistically significant (P < 0.05) in the Bakhtiari breed. It was concluded that the Shal breed gave a better response to vitamin A supplementation while the Sanjabi and Bakhtiari breeds to vitamin E. This indicates that fat-tailed breeds have dissimilar requirements for vitamins A and E supplementation. A higher level of vitamin E intake is required for raising the alpha-tocopherol content of the blood plasma above the level critical for sheep (0.8 microgram/ml).
在一项实验中，选用了90只3个伊朗肥尾羊品种的公羊羔羊，其中沙尔品种（年龄：4 - 6个月）；在另一项实验中选用了桑贾比和巴赫蒂亚里品种（年龄：6 - 9个月）。将这些羔羊分为5组，每组5 - 7只，分别给予基础日粮并添加不同水平的维生素A和维生素E。各实验组分别给予0、50或100国际单位维生素A/千克体重，以及0、15或30国际单位维生素E/千克日粮。在维生素A组中，维生素E的添加量保持在15国际单位；在维生素E组中，维生素A的添加量保持在50国际单位。在实验开始和结束时采集血浆样本，通过高效液相色谱法（HPLC）测定维生素A和维生素E的浓度。最高水平（100国际单位/千克体重）的维生素A添加显著提高了沙尔品种（P < 0.01）和巴赫蒂亚里品种（P < 0.05）血浆中的视黄醇含量。桑贾比品种中视黄醇浓度的轻微升高不显著（P > 0.05）。维生素A添加显著降低了所有三个品种血浆中的α-生育酚含量（P < 0.01）。它提高了沙尔品种羔羊的平均日体重增加量（P < 0.01），但降低了巴赫蒂亚里品种羔羊的平均日体重增加量（P < 0.05）。维生素E添加轻微降低了所有品种血浆中的视黄醇含量，在最高剂量水平下，沙尔品种的这种降低具有统计学意义（P < 0.05）。维生素E添加显著提高了所有品种血浆中的α-生育酚浓度（P < 0.01 - 0.001）。它降低了沙尔品种的平均日体重增加量（P < 0.001），但提高了其他两个品种羔羊的平均日体重增加量。在巴赫蒂亚里品种中，这种增加具有统计学意义（P < 0.05）。研究得出结论，沙尔品种对维生素A添加的反应更好，而桑贾比和巴赫蒂亚里品种对维生素E的反应更好。这表明肥尾羊品种对维生素A和维生素E添加的需求不同。要将血浆中的α-生育酚含量提高到高于绵羊临界水平（0.8微克/毫升），需要更高水平的维生素E摄入量。
