Abstract #317
Section: Physiology and Endocrinology (orals)
Session: Physiology & Endocrinology 2
Format: Oral
Day/Time: Tuesday 11:00 AM–11:15 AM
Location: Room 262
Session: Physiology & Endocrinology 2
Format: Oral
Day/Time: Tuesday 11:00 AM–11:15 AM
Location: Room 262
# 317
Hepatic one-carbon metabolism, methionine cycle, and transsulfuration pathways are altered by prepartum adiposity and feed intake in peripartal grazing cows.
M. Vailati-Riboni*1, Y. Lian1, D. Coleman1, S. Meier2, C. Burke2, J. K. Kay2, M. D. Mitchell3, C. G. Walker2, M. A. Crookenden2, A. Heiser4, J. R. Roche2, J. J. Loor1, 1Department of Animal Sciences, University of Illinois, Urbana, IL, 2DairyNZ, Hamilton, New Zealand, 3University of Queensland, Queensland, Australia, 4AgResearch, Palmerston North, New Zealand.
Key Words: BCS, prepartum nutrition, methionine cycle
Hepatic one-carbon metabolism, methionine cycle, and transsulfuration pathways are altered by prepartum adiposity and feed intake in peripartal grazing cows.
M. Vailati-Riboni*1, Y. Lian1, D. Coleman1, S. Meier2, C. Burke2, J. K. Kay2, M. D. Mitchell3, C. G. Walker2, M. A. Crookenden2, A. Heiser4, J. R. Roche2, J. J. Loor1, 1Department of Animal Sciences, University of Illinois, Urbana, IL, 2DairyNZ, Hamilton, New Zealand, 3University of Queensland, Queensland, Australia, 4AgResearch, Palmerston North, New Zealand.
Twenty 8 mid-lactation grazing dairy cows of mixed age and breed were randomly allocated to 1 of 4 treatment groups in a 2 × 2 factorial design: 2 prepartum body condition score (BCS) categories [4.0 (thin) and 5.0 (optimal); 10-point scale] and 2 levels of energy intake during the 3 wk preceding calving (75% and 125% of estimated requirements). Liver tissue was harvested by biopsy at −7, 7, and 28 d relative to calving. Samples were homogenized and used for 14C assays to investigate betaine-homocysteine S-methyltransferase (BHMT), methionine synthase (MS), and cystathionine-β-synthase (CBS) activity. Metabolites relative concentration was analyzed using a targeted GC/MS profiling approach. Data were normalized with tissue protein concentration, and subjected to repeated measures ANOVA via PROC MIXED in SAS, with BCS, Feeding, and Time as fixed effects, and cow as random effect. All enzymes were affected by time, with BHMT activity peaking (P < 0.05) at 7 d, while CBS and MS activity decreased postpartum (P < 0.05). Overall, thin cows had greater (P < 0.05) MS activity, while cows fed 125% requirements had greater (P < 0.05) CBS activity. An interaction was detected for CBS activity, as thin cows fed 125% of requirements had greater (P < 0.05) overall activity. BCS 5 cows had overall greater betaine, glycine, acetylcholine, serine, and taurine concentrations. The same metabolites, plus choline, and N-N-dimethyl glycine were overall greater in liver of cows fed 75% of requirements. An interaction was detected for the aforementioned metabolites and also methionine, cystathionine, cysteinesulfinate, and hypotaurine due to overall greater levels in BCS 5 cows fed at 75% of requirements compared with other groups. Data indicate activity of enzymes involved in hepatic choline and methionine metabolism in pasture-based cows follow a different trend to those reported for high yielding cows in confinement. Furthermore, metabolomics underscores the need to restrict BCS 5 cows prepartum to ensure an optimal transition into lactation.
Key Words: BCS, prepartum nutrition, methionine cycle
