Effect of prepartum selenium-vitamin E injection on time for placenta to pass and on productive functions.

The effect of a single injection of selenium-vitamin E containing 21.9 mg sodium selenite upon time for placenta to pass following calving and on subsequent reproductive and lactational performance was evaluated. Incidence of retained placenta was 11.4%. This amount of selenium-vitamin E did not affect the time for placenta to pass, did not reduce calving difficulty, nor did it increase number of heats prior to first breeding, decrease days open or services per conception, or increase milk the next lactation.