Politis Ioannis, Bizelis Iosif, Tsiaras Anastasios, Baldi Antonella
Department of Animal Production, Agricultural University of Athens, Athens 11855, Greece.
J Dairy Res. 2004 Aug;71(3):273-8. doi: 10.1017/s002202990400010x.
Fifty-six Holstein dairy cows from a commercial dairy herd in the Northern part of Greece were used to determine the effect of vitamin E supplementation on immune parameters, milk composition and milk quality. Cows were assigned to one of two experimental groups: control (no vitamin E supplementation) and vitamin E supplementation. Supplementation of vitamin E started 4 weeks prior to and continued up to 12 weeks after parturition. Supplementation included daily oral administration of vitamin E at 3000 i.u./cow prepartum and was reduced to 1000 i.u./cow post partum. Blood samples were collected weekly for 8 weeks starting 4 weeks before parturition, neutrophils were isolated and the following parameters were determined in neutrophils activated by phorbol myristate acetate: total cell-associated and membrane-bound urokinase plasminogen activator (u-PA) activity and superoxide production. Milk samples were collected weekly and fat, protein, lactose, somatic cell count (SCC), plasmin and plasminogen-derived activity were determined. Activated neutrophils isolated from cows that received supplemental vitamin E had higher (P<0.01) total and membrane-bound u-PA activities during the first 3 weeks after parturition and higher (P<0.01) superoxide production during week 1 prepartum and week 1 post partum compared with the corresponding values of activated neutrophils isolated from control cows. Vitamin E supplementation had no effect (P=0.28) on plasminogen-derived activity in milk. Milk obtained from cows that received supplemental vitamin E had SCC lower by 25% (P<0.05) and plasmin lower by 30% (P<0.01) than corresponding values in milk obtained from control cows. The reduction in plasmin as a result of vitamin E supplementation is very beneficial to the dairy industry because plasmin reduces the cheese-yielding capacity of milk, affects the coagulating properties of milk and its overall ability to withstand processing during cheesemaking. In conclusion, vitamin E supplementation had positive effects on the function of bovine neutrophils and milk quality in a commercial dairy herd.
来自希腊北部一个商业奶牛场的56头荷斯坦奶牛被用于确定补充维生素E对免疫参数、牛奶成分和牛奶质量的影响。奶牛被分配到两个实验组之一：对照组（不补充维生素E）和补充维生素E组。维生素E的补充在分娩前4周开始，并持续到分娩后12周。补充包括在产前每天给每头奶牛口服3000国际单位的维生素E，产后降至每头奶牛1000国际单位。从分娩前4周开始，每周采集一次血样，持续8周，分离中性粒细胞，并在佛波酯肉豆蔻酸酯激活的中性粒细胞中测定以下参数：总细胞相关和膜结合尿激酶纤溶酶原激活剂（u-PA）活性以及超氧化物生成。每周采集牛奶样本，测定脂肪、蛋白质、乳糖、体细胞计数（SCC）、纤溶酶和纤溶酶原衍生活性。与从对照奶牛分离的活化中性粒细胞的相应值相比，从接受补充维生素E的奶牛分离的活化中性粒细胞在分娩后的前3周具有更高（P<0.01）的总u-PA和膜结合u-PA活性，在产前第1周和产后第1周具有更高（P<0.01）的超氧化物生成。补充维生素E对牛奶中的纤溶酶原衍生活性没有影响（P=0.28）。从接受补充维生素E的奶牛获得的牛奶中的SCC比从对照奶牛获得的牛奶中的相应值低25%（P<0.05），纤溶酶低30%（P<0.01）。由于补充维生素E而导致纤溶酶减少对乳制品行业非常有益处，因为纤溶酶会降低牛奶的奶酪产量，影响牛奶的凝固特性及其在奶酪制作过程中承受加工的总体能力。总之，补充维生素E对商业奶牛场中牛中性粒细胞的功能和牛奶质量有积极影响。
