Effects of vitamin E on mammary and blood leukocyte function, with emphasis on chemotaxis, in periparturient dairy cows.
OBJECTIVE
To determine the effect of vitamin E supplementation on the immune system of dairy cows.


METHODS
The following immune parameters were followed: production of chemotactic factors and superoxide by mammary macrophages and chemotactic responsiveness of blood neutrophils.


METHODS
16 healthy Holstein dairy cows.


METHODS
Dairy cows were assigned to 1 of 2 experimental groups: control (no vitamin E supplementation) and vitamin E supplemented. Supplementation of vitamin E started 4 weeks before and continued up to 8 weeks after parturition, and included oral supplementation of vitamin E at the rate of 3,000 IU/cow/d. In addition, the same group of cows received 1 injection of vitamin E (5,000 IU) 1 week prior to the expected date of parturition. Blood samples were collected weekly throughout the experimental period.


RESULTS
Vitamin E supplementation enhanced by 30 to 83% (P < 0.05) chemotactic responsiveness of blood neutrophils beginning 2 weeks before to 4 weeks after parturition, compared with controls. There were no differences in production of superoxide or chemotactic factors by mammary macrophages between control and vitamin E-supplemented cows.


CONCLUSIONS
Vitamin E supplementation prevents the periparturient inhibition of neutrophil chemotaxis. It is unlikely that vitamin E affects directly the function of mammary macrophages.
Politis
I
I
Department of Animal and Food Sciences, University of Vermont, Burlington 05405, USA.
Hidiroglou
N
N
White
J H
JH
Gilmore
J A
JA
Williams
S N
SN
Scherf
H
H
Frigg
M
M
D000821:Animal Feed; D000818:Animals; D002417:Cattle; D002634:Chemotaxis, Leukocyte / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005527:Food, Fortified; D066298:In Vitro Techniques; D008264:Macrophages / Q000187:drug effects / Q000502:physiology*; D008321:Mammary Glands, Animal / Q000502:physiology*; D008892:Milk / Q000166:cytology* / Q000502:physiology; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D049590:Postpartum Period / Q000097:blood / Q000502:physiology*; D012643:Selenium / Q000097:blood; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D014810:Vitamin E / Q000097:blood / Q000494:pharmacology*
D013481:Superoxides; D014810:Vitamin E; D012643:Selenium