Effect of Different Fatty Acid Profiles in the Maternal and Finishing Diet on Subcutaneous Adipose Tissue Fatty Acid Profile and Gene Expression

The objective of this study was to evaluate the effects of feeding eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to ewes during late gestation on finishing lamb subcutaneous adipose tissue (AT) fatty acid (FA) profile and gene expression. Lambs born from ewes supplemented with Ca salts of the PUFA EPA and DHA, or palm FA distillate (PFAD) high in palmitic and oleic acid at 0.39% DM during the last 50 d of gestation were used. Lambs were weaned at 60 d of age and adapted to a high concentrate diet for 1.5 mo. After adaptation, 74 lambs (28 pens) were blocked by initial BW when the finishing period started and used in a 2x2 factorial arrangement of treatments using the factors of dam diet and lamb diets containing PUFA or PFAD at 1.5% DM. Lambs were slaughtered after 42 d of supplementation and subcutaneous AT samples were obtained for FA analysis and gene expression analysis of 27 genes. A lamb x dam treatment interaction was observed for EPA (P=0.02) and DHA (P=0.04) where supplementation of lambs increased the concentrations of EPA and DHA in AT, but the increase was greatest for lambs born from PFAD ewes vs. PUFA ewes. This same lamb x dam treatment interaction was observed for the omega-6:omega-3 FA ratio (P=0.01). A significant lamb x dam treatment interaction was observed for elongation of very long chain fatty acid 2 (P=0.01); lambs that were supplemented with the same type of fatty acids as their dams had lower mRNA expression compared to lambs supplemented with fatty acids that were opposite of their dams. There was a tendency for mRNA expression of hormone sensitive lipase (P=0.08) to be decreased in AT of PUFA supplemented lambs that were born from PUFA ewes. Expression of leptin tended (P=0.08) to be lower in lambs that were supplemented with PUFA vs. PFAD during the finishing period. A significant dam effect was observed for glucose-dependent insulinotropic polypeptide receptor (P=0.01); expression was decreased in lambs from PUFA dams compared to lambs from PFAD dams. The changes in AT mRNA expression suggest that lipogenesis may be decreased in finishing lambs that are supplemented with PUFA and are born from dams supplemented with PUFA during late gestation. These results suggest an interaction between FA supplementation of ewes during late gestation and supplementation of FA to lambs during the finishing period on subcutaneous AT FA and gene expression.