Effect of vitamin E supplementation on neutrophil function, milk composition and plasmin activity in dairy cows in a commercial herd

Abstract

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.

Reevaluation of vitamin E supplementation of dairy cows: bioavailability, animal health and milk quality

“…Interestingly, selenium was fed to all cows at 0.3 ppm of total dry matter. Similar results were obtained in another study that was undertaken in a commercial farm in Greece implementing oral administration of 3000 IU/cow per day starting 4 weeks before the expected day of parturition and then reduced to 1000 IU/cow per day postpartum (Politis et al, 2004). Baldi et al (2000) suggested that vitamin E supplementation (oral administration of 2000 IU/cow per day from day 14 before up to day 7 after parturition) reduces SCC by 20% to 30%, compared with the corresponding values of the control that received only 1000 IU/cow per day during the same time period.…”

“…Thus, vitamin E, by affecting the expression of u-PA gene facilitates movement of neutrophils to the mammary gland during inflammation. Similar results concerning the ability of vitamin E to restore immune competency at calving were obtained by Politis et al (2004) in a trial carried out in a commercial herd in Greece using dietary supplementation (3000 IU/cow per day) from week 4 before up to week 4 after parturition. This study documents the ability of vitamin E to restore the function of neutrophils in a different environment and a less intensive management system in a country where dairy cows are likely to encounter less oxidative stress than cows in the United States of America.…”

“…A subset of these data, involving mainly immune parameters, were published (Politis et al, 2001). The third vitamin E feeding trial was carried out in Greece and included oral supplementation of 3000 IU/cow per day starting 4 weeks before the expected day of parturition and then reduced to 1000 IU/ cow per day postpartum (Politis et al, 2004). All farms can be classified as having low incidence of clinical mastitis (,12 cases/100 cows per year) or medium incidence (13 to 26 cases/100 cows per year).…”

“…Furthermore, increased plasmin reduces the stability of the long life milk (UHT milk) and it is associated with production of bitter flavors (Ismail and Nielsen, 2010). Politis et al (2004) demonstrated that vitamin E supplementation resulted in a reduction in plasmin levels in milk by 30%. Milk having lower levels of plasmin has an increased ability to withstand processing for the manufacturing of essentially all dairy products.…”

The effect of fish oil supplementation of pregnant and lactating ewes on milk production and lamb performance

“…This effect may also have led to reduced body fat mobilisation, a finding that corresponds with the lower live weight losses observed in ewes supplemented with fish oil. Vitamin E supplementation had no main effect upon milk yield or composition and the metabolic significance of the interaction between fat source and vitamin E concentration resulting in lower milk protein production in ewes fed concentrate MB is not clear, particularly as vitamin E supplementation of lactating cattle did not affect milk protein yield in the studies of Politis et al (2004), Bell et al (2006) or Pottier et al (2006). Endogenous milk fat synthesis principally results in the secretion of short-and medium-chain fatty acids, with a significant contribution made by C 16:0 (Bauman and Griinari, 2001).…”