Effect of supplemental vitamin E during prepubertal development and early gestation on reproductive performance and nutrient metabolism in gilts

Abstract

The effect of feeding barley–canola-meal diets with supplemental vitamin E (dl-α-tocopherol acetate) at 0, 50 or 100 mg kg−1 on selected reproductive functions and nutrient absorption and retention was determined using Landrace × Yorkshire gilts. In exp. 1 (n = 150), gilts were fed three gestation diets, containing by analysis 23.5, 55.7 and 113.5 mg kg−1 of vitamin E respectively in diets 1, 2 and 3, from first estrus until approximately 33 or 65 d of gestation. Gilts fed diet 2 had a higher (P = 0.02) number of corpora lutea (13.8 ± 0.5 vs. 12.0 ± 0.5) at 65 d of gestation than the gilts fed diet 1. In exp. 2, gilts (n = 159) were fed three finisher diets, containing by analysis 17.6, 87.8 and 126.5 mg kg−1 of vitamin E, during prepubertal development period (59.2 ± 0.4 to 86.7 ± 0.8 kg body weight) and then switched (n = 150) to three gestation diets, containing 16.4, 54.2 and 103 mg kg−1 of vitamin E, until 58.7 ± 0.7 d of the gestation period. Gilts fed diet 3 had 16% lower (P < 0.05) anestrus than the gilts fed diet 1. The ovulation rate, number of live embryos and fetal survival were not influenced (P > 0.05) by supplemental vitamin E. The serum level of α-tocopherol was linearly increased (P < 0.01) by feeding supplemental vitamin E in both experiments. Feeding supplemental vitamin E had no consistent beneficial effect on serum progesterone or on the apparent absorption and retention of selected nutrients during the prepubertal and gestation periods. The results indicated that feeding supplemental vitamin E at above 1988 NAS–NRC recommended levels during prepubertal development and early gestation only slightly improved certain reproductive traits in gilts. Key words: Gilts, vitamin E, ovulation rate, fetal survival, metabolism