Effects of parenteral administration of vitamin E on health of periparturient dairy cows.

OBJECTIVE

To determine the effect of administration of vitamin E (D-alpha-tocopherol) on the incidence of retained placenta, metritis, and clinical mastitis during early lactation and on tocopherol concentrations.

DESIGN

Prospective randomized controlled study.

ANIMALS

420 Holstein cows.

PROCEDURE

Vitamin E (3,000 mg, IM, once) was administered to 204 cows B to 14 days before expected parturition, and 216 control cows were not treated. The number of cows that had retained placenta, metritis, clinical mastitis, displaced abomasum, and clinically apparent acetonemia or hypocalcemia were recorded. Serum concentrations of tocopherol, the tocopherol:cholesterol ratio, and glutathione-peroxidase activity were determined from samples obtained before administration of vitamin E, 7 and 14 days after administration, and at 30 days after parturition from 36 treated and 36 control cows.

RESULTS

Administration of vitamin E significantly decreased the incidence of retained placenta and metritis (13/204 [6.4%] and 8/204: [3.9%], respectively, for the vitamin E-treated group; 27/216 [12.5%] and 19/ 216 [8.8%], respectively, for the untreated group) but did not affect the incidence of clinical mastitis. Serum vitamin E concentration was significantly higher in treated than in control cattle at 7 and 14 days after administration, but serum tocopherol: cholesterol ratio was significantly higher only at 7 days after administration.

CLINICAL IMPLICATIONS

Parenteral administration of a single injection of vitamin E before parturition may decrease the incidence of retained placenta and metritis in dairy cows but will increase serum concentrations for 7 to 14 days after administration.