Effects of selenium and vitamin E administration on breeding of replacement beef heifers.

Forty-eight heifers were given selenium and/or vitamin E or no supplementation from age of weaning (8 months) for 6 months prior to breeding. Blood plasma levels were monitored and some reproductive traits were assessed. The overall pregnancy rate (33%) in the control group was significantly (P less than 0.05) lower than in the vitamin E-supplemented groups (58-83%). Age of first heat, breeding and calving were unaffected by vitamin E and/or selenium supplementation.