Our aim was to evaluate the effects of increasing dietary levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) during the final third of gestation on plasma and milk fatty acid (FA) profiles of ewes and their offspring. Additionally, correlation between maternal and offspring plasma, colostrum, and milk FA profiles were examined. Seventy-two pregnant ewes (92.2 ± 2.94 kg body weight at d 100 of gestation) were blocked by body condition score and randomly assigned to one of three diets containing 0, 1, or 2% of a Ca salt of FA enriched with EPA and DHA during the last 50 d of gestation. Animals were housed in 8 pens per treatment (3 ewes per pen) during the supplementation period. At lambing, all ewes were penned together and offered a diet without FA supplementation. For FA profile, blood samples were collected from ewes at d -20 prepartum, at lambing, and d 15 postpartum. Lamb plasma samples were obtained at birth (0.5 to 8 h post-suckling). Colostrum (0.5 to 8 h postpartum) and milk (d 15 postpartum) were also collected. Data were analyzed using a randomized complete block design. The model included the fixed effects of the treatment for lamb plasma FA profile; and the fixed effects of treatment, time, and their interaction for ewe plasma and colostrum and milk FAprofile. Supplementation with EPA and DHA increased (diet by time interaction; P ≤ 0.06) the polyunsaturated FA (PUFA; C20:40, C20:5, and all omega 3) in ewe plasma until lambing but was similar between treatments 15 d post lambing. Colostrum from supplemented ewes showed greater PUFA (C22:5 and C22:6) concentrations and the difference decreased in the milk (diet by time interaction; P < 0.01), although the colostrum PUFA increase was not correlated with most individual plasma PUFA (C18:2, C20:3n6 and n3, C20:4, C20:5, C22:5, and C22:6), except for C18:3, which showed a positive association (P = 0.03). Furthermore, colostrum PUFA concentrations were positively correlated with the FA composition of lamb plasma post-suckling (P < 0.02). The PUFA concentrations were also increased in lamb plasma at lambing (P < 0.01), suggesting potential effects on neonatal lipid metabolism. These findings demonstrate that dietary supplementation with EPA and DHA, initiated 50 days before lambing and terminated at parturition, can alter the FA composition of maternal plasma, colostrum, and milk, and also influence the plasma FA profile of the offspring.
Keywords: Polyunsaturated fatty acids; colostrum; plasma; sheep.
This experiment explored how eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation during late gestation affects the fatty acid composition of dam plasma, milk, and plasma of the offspring. Pregnant ewes were divided into three groups, each receiving a different amount of an EPA and DHA source at 0, 1%, or 2% of dry matter intake. Supplementation started 50 days before expected lambing. Plasma samples were taken from the ewes before and after giving birth, and from the lambs shortly after birth. Colostrum was collected at lambing and milk at 15 days postpartum. We found that the ewes who received EPA and DHA had these fatty acids in their plasma over time. Although the increase in plasma fatty acids was not directly associated to the fatty acids’ concentration in colostrum, the colostrum itself had greater levels of these fatty acids. Lambs born from ewes supplemented with EPA and DHA also showed increased concentration of these fatty acids in their plasma, suggesting that the maternal diet had a positive effect on the newborns’ fatty acid metabolism. Therefore, feeding EPA and DHA to ewes in late gestation can improve the nutritional quality of their milk and may support better health outcomes for their lambs right from birth.
© The Author(s) 2025. Published by Oxford University Press on behalf of the American Society of Animal Science.