Maternal supply of fatty acids during late gestation on offspring's growth, carcass characteristics and energy metabolism in sheep

Growth is an important factor that drives animal production; and it can be manipulated through maternal nutrition. We evaluated the effect of supplementing different fatty acids (FA) to ewes during late gestation on lamb growth, feed intake (FI), carcass characteristics (CC), and energy metabolism (by conducting a glucose tolerance test [GTT]). Fifty-four pregnant-ewes (n=18) were supplemented from day 100 gestation until birth. Treatments were: no FA supplementation (CONT); monounsaturated FA supplementation (MUFA); or polyunsaturated FA supplementation (PUFA). At weaning lambs were allotted based on sex and fed a common finishing diet for 54 days; FI was daily measured. Lambs body weight (BW) was recorded on weaning day (d0), d28, and d54. Eighteen lambs (six per treatment) were used for a GTT on d55. On d56, other 18 lambs were harvested for CC measurements. Offspring data was analyzed as a 2x2 factorial (FA and sex) using repeated measurements. Ewe supplementation did not affect lamb FI, neither plasma glucose on the GTT. There was a FA*sex interaction for insulin concentration in the GTT. Males plasma insulin concentration increased as FA unsaturation degree increased, the opposite happened with females. There was a FA*sex interaction on lamb BW. Females were heavier than males from CONT and MUFA; males were heavier than females from PUFA. Lambs born from PUFA had a heavier hot carcass weight (HCW). In conclusion, FA supplementation during late gestation modified growth, insulin sensitivity, and HCW in lambs; these changes depended on the FA unsaturation degree of the supplement and lamb sex.