Effect of vitamin E supplementation on neutrophil function, milk composition and plasmin activity in dairy cows in a commercial herd.
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.
Politis
Ioannis
I
Department of Animal Production, Agricultural University of Athens, Athens 11855, Greece. i.politis@aua.gr
Bizelis
Iosif
I
Tsiaras
Anastasios
A
Baldi
Antonella
A
D000818:Animals; D002417:Cattle / Q000502:physiology*; D002452:Cell Count; D019587:Dietary Supplements; D005260:Female; D005341:Fibrinolysin / Q000378:metabolism*; D007785:Lactose / Q000032:analysis; D008055:Lipids / Q000032:analysis; D008892:Milk / Q000737:chemistry* / Q000166:cytology / Q000201:enzymology; D008894:Milk Proteins / Q000032:analysis; D009504:Neutrophils / Q000502:physiology*; D010958:Plasminogen / Q000378:metabolism; D011247:Pregnancy; D013481:Superoxides / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism; D014810:Vitamin E / Q000008:administration & dosage*
D008055:Lipids; D008894:Milk Proteins; D013481:Superoxides; D014810:Vitamin E; D010958:Plasminogen; D005341:Fibrinolysin; D014568:Urokinase-Type Plasminogen Activator; D007785:Lactose; D013755:Tetradecanoylphorbol Acetate