3 Effect of feeding rumen-protected choline around the periconceptional period on plasma choline metabolites and pregnancy rate in beef cows
M. Sagheer A , M. L. Haimon A , D. Heredia B , F. Tarnonsky B , M. Venturini B , A. Gonella-Diaza B , N. DiLorenzo B , J. W. McFadden C and P. J. Hansen AA Department of Animal Sciences, University of Florida, Gainesville, FL, USA
B North Florida Research and Education Center, University of Florida, Gainesville, FL, USA
C Department of Animal Science, Cornell University, Ithaca, NY, USA
Reproduction, Fertility and Development 35(2) 126-126 https://doi.org/10.1071/RDv35n2Ab3
Published: 5 December 2022
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the IETS
Several epigenetic processes, including DNA methylation and histone modifications, regulate DNA transcription, embryonic development, fetal growth, and response to environmental cues. It has previously been shown that supplementation of choline (a methyl donor) to embryo culture medium increased DNA methylation of blastocysts and programmed development to increase birth and weaning weights of calves born after embryo transfer. The long-term objective of the current research is to evaluate whether feeding rumen-protected choline (RPC) during the periconceptional period also programs fetal development. Specific objectives of the current experiments were to determine the effect of feeding RPC on plasma concentrations of choline and its derivates and to test whether feeding RPC increases pregnancy rate and reduces embryonic loss in beef cows subjected to timed artificial insemination (TAI). In the first experiment, 25 postpartum suckled beef cows were randomly assigned to be individually fed either 0, 30, 60, or 90 g of RPC mixed in 454 g of ground corn gluten for 9 days using a Super SmartFeed® (SSF) machine (C-Lock). Blood samples were collected on days −1, 5, 5.5, 10, and 10.5 to determine plasma concentrations of free choline, methionine, dimethylglycine, betaine, trimethylamine N-oxide, phosphatidylcholine (PC), sphingomyelin (SM), and lysophosphatidylcholine (LPC) by mass spectrometry. By analysis of variance, there were no differences in any metabolite between RPC feeding groups (P > 0.05). Mean choline plasma concentrations were 3.6 ± 0.8, 3.2 ± 0.8, 2.7 ± 0.9, and 4.6 ± 1.6 nmol/mL for 0, 30, 60, and 90 g RPC, respectively. Regression analysis indicated linear (P = 0.05) and quadratic effects (P = 0.014) of total intake of RPC on the day of sampling on plasma choline concentrations, with values increasing as intake increased. Similar linear (P = 0.093) and quadratic (P = 0.020) effects of RPC intake were found for plasma SM concentration. Moreover, plasma concentration of choline was positively correlated with concentrations of betaine (r = 0.44; P < 0.001), PC (r = 0.42; P < 0.001), SM (r = 0.35; P < 0.005), and LPC (r = 0.34; P < 0.007). In the second experiment, 211 postpartum first-service, suckled beef cows were blocked by breed and bodyweight and assigned randomly to RPC or control group. Cows were synchronised with a 7-day CO-Synch + controlled internal drug release protocol for TAI and individually fed 60 g RPC in 454 g ground corn gluten (RPC) or 454 g ground corn gluten (control) through the SSF machine from Day 1 until 7 days after TAI. Pregnancy diagnosis was performed with ultrasonography at Days 28 and 42 post-TAI. Pregnancy per AI at day 28 was 49% (55/112) for RPC and 52% (51/99) for control (P = 0.61). Embryonic losses between Day 28 and 42 was 4.1% for RPC and 4.8% for control (P = 0.831). In conclusion, feeding RPC around the periconceptional period did not increase pregnancy rate in beef cows. Future work will focus on the consequences of RPC feeding on the postnatal phenotype of the subsequent calves.
