Maternal Supply of Fatty Acids during Late Gestation on Offspring’s Growth, Metabolism, and Carcass Characteristics in Sheep

SIMPLE SUMMARY: Growth is an important factor that drives animal production, and it can be manipulated through maternal nutrition. In ruminants, previous studies suggested that maternal nutrition during late gestation with polyunsaturated fatty acids altered growth, energy metabolism, muscle development, and body composition of the offspring. This study investigates the effect of supplementing different sources of fatty acids during late gestation on offspring energy metabolism and growth during the finishing period. Maternal fatty acid supplementation during late gestation modified growth, insulin sensitivity, and hot carcass weight in lambs; these changes depended on the unsaturation degree of the fatty acid supplement and lamb sex. Hence, fatty acid supplementation of the gestating ewe can potentially have a lifelong impact on offspring’s growth performance and metabolism, and could be used as a possible management alternative to enhanced offspring productivity. ABSTRACT: Lambs born from dams supplemented with different sources of fatty acids (FA) during late gestation have a different growth rate and plasma glucose concentration. The main objectives of this experiment were to evaluate the effect of supplementing different sources of FA during late gestation on offspring plasma metabolite concentrations, growth, and on a glucose tolerance test (GTT) during the finishing phase. Fifty-four lambs (18 pens, 3 lambs/pen) were born from ewes supplemented during late gestation with one of three treatments: (1) no FA (NF); (2) a source of monounsaturated FA (PDS, 1.01% of Ca salts); or (3) a source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (EDS, 1.01% of Ca salts containing). At birth (day 0), supplementation ceased, and all ewes and lambs were placed in a common pen. On day 60, lambs were weaned, grouped by sex, blocked by body weight (BW), and placed on a common finishing diet for 54 days (FP). One lamb per pen was used for the GTT after the FP. There was a tendency for FA × Sex × Day interaction (p = 0.08) on lamb growth during the finishing period, with PDS females being heavier than PDS males, while EDS males were heavier than EDS females at day 60. There was a tendency for FA × Sex interaction (p = 0.06) for plasma insulin concentration for the GTT. Plasma insulin concentration of wethers increased as FA unsaturation degree increased during the GTT; the opposite happened with the plasma insulin concentration of female lambs. In conclusion, FA supplementation during late gestation tended to modified growth and insulin response to a GTT; these changes differed with the degree of FA unsaturation of the supplement and lamb sex.