Concentrations of α-Tocopherol after Intramammary Infusion of Escherichia coli or Lipopolysaccharide

Abstract

Fifteen Holstein cows were used in a trial involving intramammary challenge to determine the effects of acute clinical mastitis on the concentrations of α-tocopherol in milk and plasma and the concentrations of neutrophils in milk and blood. Cows were assigned to one of three experimental groups challenged by intramammary infusion of lipopolysaccharide, Escherichia coli, or sterile phosphate-buffered saline. All quarters infused with lipopolysaccharide or E. coli were diagnosed with clinical mastitis on d 1 and 2 after challenge. Acute inflammation caused by intramammary infusion of lipopolysaccharide or E. coli resulted in increased concentrations of α-tocopherol in milk in challenged quarters but had no effect on concentrations of α-tocopherol in plasma. Concentrations of α-tocopherol in milk and blood neutrophils did not differ among treatment groups. Concentrations of α-tocopherol did not differ between milk and blood neutrophils. Approximately 25% of the α-tocopherol in milk from glands with clinical mastitis was associated with neutrophils, and <10% of the α-tocopherol in milk from nonmastitic glands was associated with neutrophils. A shift toward sources of α-tocopherol other than synthesized milk fat occurred during acute inflammation in the mammary gland.