Expression of genes related to liver fatty acid metabolism in fat-tailed and thin-tailed lambs during negative and positive energy balances

Effects of isochronal induced feed restriction during the transition period on mRNA abundance of the hepatic genes related to lipid metabolism in fat-tailed ewes

The process of fat mobilization during the transition period (TP) requires deep re-orchestration of the energy indices, and understanding its mechanism has generated considerable interest among the TP-related studies. The present study aims to validate the effect of feed restriction and TP on the mRNA abundance of hepatic genes related to fat metabolism in fat-tailed sheep. Twenty pregnant ewes with the age of 40.8 ± 6.2 (mean ± standard error) month were randomly assigned to control (n = 10) or restriction (n = 10), and investigated from week - 5 to 5 relative to parturition. Control animals received 100% DM during the trial. Restriction animals received 100% DM through weeks - 5, - 1, 1 and 5 and were fed with 50, 65, and 80% DM in the weeks - 4, - 3, - 2 and 2, 3, and 4, respectively. On the third week of experiment (65%) during both pre- and post-partum, the hepatic tissue was biopsied, and the mRNA load of the fatty acid synthase, acetyl-CoA carboxylase, carnitine palmitoyltransferase (CPT) 1, CPT2, and acyl-CoA synthase long-chain family member-1 genes was quantified by the TaqMan qPCR technique. Data were analyzed using the mixed model procedure of SAS. The mRNA abundance of the target genes was not influenced by feed restriction, during the pre- and post-partum periods. Parturition suppressed the mRNA abundance of target genes in both groups. It can be concluded that the fat-tailed sheep are well adapted to feed scarcity in the harsh environment and would have a higher capacity for the metabolism of fat mobilization during the negative energy balance.