J. J. Barrett,
J. S. Hogan 1,
W. P. Weiss,
K. L. Smith
The Ohio State University Department of Animal Sciences
Fifteen Holstein cows were used in a trial involving intramammary challenge to determine the effects of acute clinical mastitis on the concentrations of a-tocopherol in milk, plasma, and milk and blood neutrophils. Cows were assigned to one of three experimental groups challenged by intramammary infusion of either endotoxin, Escherichia coli, or sterile phosphate-buffered saline. All quarters infused with lipopoly-saccharide or E. coli were diagnosed with clinical mastitis on days one and two after challenge. Acute inflammation caused by intramammary infusion of endotoxin of E. coli resulted in increased concentrations of a-tocopherol in milk in challenged quarters but had no effect on concentrations of a-tocopherol in plasma. Approximately 25% of the a-tocopherol in milk from glands with clinical mastitis was associated with neutrophils compared with <10% in nonmastitic glands. A shift toward sources of a-tocopherol other than synthesized milk fat occurred during acute inflammation in the mammary gland.
1 For more information, contact at: The Ohio State University, Ohio Agricultural Research and Development Center, 302 Pounden Hall, 1680 Madison Ave., Wooster, OH 44691; 330-263-3801; e-mail: hogan.4@osu.edu