Effect of selenium and a-tocopherol supplementation on postpartum reproductive function of dairy heifers at pasture.

Abstract The objective of this study was to investigate the effects of selenium (Se) and α-tocopherol supplementation on uterine involution and ovarian function in dairy heifers fed a prepartum diet containing low concentrations of Se and α-tocopherol. Twenty-four pregnant Friesian heifers were randomly allocated to one of four experimental groups in a 2 × 2 design balanced for age and body weight. Prepartum treatments consisted of supplementation with either 2 intraruminal Se pellets or 3600 mg of α-tocopherol po 4 times per wk, or both. Control animals received no supplementation. For 8 wk before calving, the heifers were fed exclusively on pasture hay which contained less than 10 μg/kg of Se and 19 mg/kg of α-tocopherol. After calving, the heifers grazed perennial ryegrass and white clover pasture. Concentrations of Se and α-tocopherol in serum for the prepartum heifers of the control group were 10 ng/ml and 1.3 μg/ml, respectively, indicating deficiencies of these nutrients. Treatment with Se and α-tocopherol increased prepartum serum concentrations of Se and α-tocopherol to 74 ng/ml and 5 μg/ml, respectively (P