PSXIV-4 Fetal programming effect of rumen-protected methionine on Angus-Simental heifer offspring’s performance and adipogenesis, oxidative stress and DNA methylation gene expression regulation

Abstract

Abstract An extensive body of literature reported positive effects of Rumen-Protected Methionine (RPM) on dairy cattle; however, its effects are unknown on beef cattle. The objective of this study was to assess the effect of RPM supplementation on Angus-Simmental heifer’s offspring during late gestation, lactation, and after weaning (~65d). Ninety days prior to calving, 22 Angus-Simmental heifers were stratified by body weight (454 ± 85 kg; BW) and randomly assigned to dietary treatments: 1) Control diet (CTRL), and 2) Control diet + RPM (RPM). Dams had access to Bermuda hay ad libitum, and a soy hull:corn gluten based supplement. After weaning, calves were allocated by dietary treatments based on their dam’s treatment. Calves received Bermuda hay ad libitum and early-wean feed supplement after weaning. Offspring’s BW and Longissimus dorsi (LM) muscle samples were obtained on days 0, 25, 50, 100 after weaning. Messenger RNA was extracted from LM for RT-qPCR analysis. There was a tendency for RPM calves to be heavier at birth compared to control calves (P = 0.07). Although, no differences in BW were detected at weaning and after weaning (P = 0.20). Calves average daily gain between birth and weaning was greater for RPM calves as compared to CON (P = 0.02) suggesting a greater milk production, with no differences after weaning (P = 0.53). RT-qPCR results showed a treatment × time interaction for PPARG, LPL, CEBPG, DNMT1, SOD2 and NOS3 (P < 0.05). Furthermore, PPARG had a treatment and a time effect, which was upregulated in RPM calves (P < 0.01) from 50 to 100 days after weaning. In conclusion, dam’s RPM supplementation during late gestation increased offspring’s BW when inside the womb and probably their milk production. Offspring’s RPM supplementation after weaning potentially stimulates an early differentiation of adipocytes in LM samples, detected by PPARG upregulation.