Maternal supply of a source of omega-3 fatty acids and methionine during late gestation on the offspring's growth, metabolism, carcass characteristic, and liver's mRNA expression in sheep

Abstract

The objective of the present experiment was to evaluate the effect of maternal supplementation with fatty acids (FAs) and methionine (Met) during late gestation on offspring growth, energy metabolism, plasma resolvin (RvD1) concentration, carcass characteristics, and hepatic mRNA expression. Ewes (5 pens/treatment; 3 ewes/pen) blocked by body weight (BW) were assigned to one of four treatments from day 100 of gestation until lambing. The treatments were: basal diet (NS) without FAs or Met supplementation; FA supplementation (FS; 1.01 % of Ca salts, containing n-3 FA); Met supplementation (MS; 0.1 % of rumen-protected methionine); and FS and MS (FS-MS). At birth (day 0), ewes and lambs were placed in a common pen. On day 60, lambs were weaned, sorted by sex, blocked by BW, and placed on a common finishing diet for 54 d (FP). A lamb per pen was used for a glucose tolerance test (GTT) after the FP. Carcass characteristics were recorded on day 56. Lamb data were analyzed as a randomized complete block design with a 2 × 2 × 2 factorial arrangement, with repeated measurements when needed (SAS 9.4). At weaning, lambs born to MS- or FS-fed ewes were heavier than lambs born from FS-MS ewes (FS × MS × Time; P = 0.02). A marginal significant FS × MS interaction (P = 0.09) was also observed on RvD1; lambs born to ewes in the NS and FS-MS treatments showed a lower RvD1 plasma concentration when compared with lambs born to FS- or MS-fed ewes. Lambs born to dams fed FA showed an increase (P = 0.05) in liver COX-2 mRNA relative expression. Lambs born to ewes supplemented with Met showed an increase (P = 0.03) in liver FABP4 mRNA expression. An FS × MS × Time interaction (P = 0.07) was observed in plasma glucose during the GTT; lambs born from FS-fed ewes showed lower plasma glucose concentration than lambs born to Met-supplemented ewes at 2 min after bolus administration. During the GTT, a marginal significant effect (P = 0.06) was observed for the lamb average insulin concentration due to maternal Met supplementation during late gestation, where these lambs had the lowest plasma concentration. Contrary to our hypothesis, the interaction of FA and Met supplementation during late gestation did not show a greater positive effect on offspring postnatal growth and metabolism. However, the individual supplementation of each nutrient has an effect on offspring development with a concomitant change in markers involved in the inflammatory response and energy metabolism.