The Effects of Supplementing EPA and DHA during Late Gestation on Ewe Metabolic Profile and Milk Production

Fatty acids are involved in the regulation of many physiological pathways, including those involve in gene expression and energy metabolism. Therefore, our objective was to investigate the impact of supplementing ewes with the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahenaenoic acid (DHA) during late gestation on ewe performance, metabolic profile of ewes and their milk production. Eighty-four gestating ewes were blocked by conception date into group pens with 3 animals per pen and randomly assigned to a diet enriched with monounsaturated fatty acids (MUFA using EnerG II as source), or the polyunsaturated fatty acids (PUFA, using Strata G113 as a source) EPA and DHA during the last 50 days of gestation. The dose of EPA and DHA supplemented was 18 mg per kg of metabolic body weight (BW^0.75), with total fat supplementation on MUFA and PUFA being fed at the same percent of the diet.. After lambing, ewes and lambs were placed on pasture. The ewes were weighed and body condition scored on days 0, 30, 80 and 120 (weaning) of the experiment. Blood samples were taken on days 0, 30, 50 (lambing), 80 and 120 and plasma was analyzed for concentrations of glucose and non-esterified fatty acids (NEFA). Milk yield and composition were measured at 30 days postpartum. There was no difference (P > 0.05) in body weight or body condition score (BCS) between treatments. No significant differences (P > 0.05) were observed for plasma glucose and NEFA concentrations among ewes supplemented with MUFA or PUFA. Neither milk yield nor milk protein, fat, lactose, solids, somatic cell count (SCC), milk urea nitrogen (MUN), energy corrected milk (ECM) or net energy of lactation (NE_L) were different (P > 0.05) among treatments. These results suggest that supplementation of EPA and DHA during late gestation has no effect on ewe metabolic profile or milk production. Further laboratory analyses will determine if fatty acid composition of ewe plasma and milk were altered by feeding EPA and DHA. Future research should investigate the potential effects of supplementing higher doses of EPA and DHA on metabolism and milk production.