The aim of this study was to test if vitamin E supplementation during late gestation and early lactation would affect the weight of ewes under nutritional restriction and the performance of their lambs. Mature Rambouillet ewes (n = 37) were fed a diet that supplied 70 % of the energy and 80 % of recommended protein requirements and randomly assigned to either vitamin E (vit E, n = 20, 4 IU of α-tocopherol kg(-1) of live weight) or control (n = 17, without vitamin E supplementation). During the experimental period, the mean weight of ewes decreased from 74.6 ± 2.4 to 58.1 ± 2.2 kg. Weight loss of ewes was slightly less for the vit E than the control (-65 vs -124 g day(-1), SEM = 46; P = 0.07). Lambs born from vit E-supplemented ewes were heavier than lambs from the control and grew significantly faster (239 vs 195 g day(-1), SEM = 29.3, P < 0.05) with heavier weights at weaning (16.5 vs 13.5 kg, SEM = 1.8, P < 0.05). Besides, birth weight, weaning weight and daily weight gain favoured to single lambs and to male lambs (P < 0.05). Weaning weight was positively correlated to birth weight (P < 0.05) and weight gain (P < 0.001). When the nutrient requirements for ewes are not met, supplementation of vitamin E during late gestation and early lactation might be an effective strategy to minimise ewe weight loss as well as to increase lamb growth.
Keywords: Birth weight; Nutritional restriction; Vitamin E; Weaning weight; Weight gain.