Effects of vitamin E supply during late gestation and early lactation upon colostrum composition, milk production and quality in nutritional restricted ewes

The aim of this study was to test if supplemental vitamin E during late gestation and early lactation to ewes facing a moderate nutritional restriction and suckling lambs from different litter size and sex would affect colostrum composition and milk yield and composition. Mature Rambouillet ewes (n=37, 22°N) receiving 70% of energy and 80% of protein requirements were randomly assigned to either of two treatments: intramuscular injections of vitamin E (VitE; n=20, 4 IU vitamin Ekg−1 of live weight) in weekly intervals from 50 days before partition until 60 days of lactation, and control (CON; n=17, without VitE treatment). While colostrum protein and fat concentrations did not differ between treatments (P>0.05), lactose content favoured to the VitE-ewes (1.9% vs. 1.2%, P<0.001). Colostrum protein concentration was affected by litter size favouring to twin lambs (14.3% vs. 17.3%, P<0.05). In addition, litter size tended to affect lactose content, favouring to those ewes suckling twins (1.4% vs. 1.8%, P=0.08). The average milk yield was 2039gday−1, without differences (P>0.05) between treatments and litter size. The average milk concentrations of protein, lactose and solids-non-fat did not differ (P>0.05) between treatments. Yet, milk fat content favour to the VitE-ewes (5.7% vs. 5.2%, P<0.05). Milk concentrations of protein, fat, lactose and solids-non-fat were not affected (P>0.05) by litter size. Non-significant treatment×litter size interactions (P>0.05) were observed for milk yield, milk compositions of protein, fat and lactose and solids-non-fat. When the nutritional requirements are not met, treatment of vitamin E to ewes during late gestation and early lactation might be an strategy to improve the quality of both colostrum (>lactose) and milk (>fat).