EFFECT OF SUPPLEMENTAL VITAMIN-E DURING PREPUBERTAL DEVELOPMENT AND EARLY GESTATION ON REPRODUCTIVE-PERFORMANCE AND NUTRIENT METABOLISM IN GILTS

The effect of feeding barley-canola-meal diets with supplemental vitam in E (dl-alpha-tocopherol acetate) at 0, 50 or 100 mg kg-1 on selected reproductive functions and nutrient absorption and retention was dete rmined using Landrace x Yorkshire gilts. In exp. 1 (n = 150), gilts we re fed three gestation diets, containing by analysis 23.5, 55.7 and 11 3.5 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 h ad 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, gi lts (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 developmen t period (59.2 +/- 0.4 to 86.7 +/- 0.8 kg body weight) and then switch ed (n = 150) to three gestation diets, containing 16.4, 54.2 and 103 m g kg-1 of vitamin E. until 58.7 +/- 0.7 d of the gestation period. Gil ts fed diet 3 had 16% lower (P < 0.05) anestrus than the gilts fed die t 1. The ovulation rate, number of live embryos and fetal survival wer e not influenced (P > 0.05) by supplemental vitamin E. The serum level of alpha-tocopherol was linearly increased (P < 0.01) by feeding supp lemental vitamin E in both experiments. Feeding supplemental vitamin E had no consistent beneficial effect on serum progesterone or on the a pparent absorption and retention of selected nutrients during the prep ubertal and gestation periods. The results indicated that feeding supp lemental vitamin E at above 1988 NAS-NRC recommended levels during pre pubertal development and early gestation only slightly improved certai n reproductive traits in gilts.