This episode was recorded at the 2025 Florida Ruminant Nutrition Symposium. To watch the webinar, visit our Real Science Lecture Series page.
Episode 140: Rumen Protected Choline During Peri-Conceptional Period Programs Postnatal Phenotype
Timestamps:
Dr. Hansen’s lab conducted several in vitro experiments where choline chloride was supplemented to beef embryo culture media for the first seven days of embryonic development. Calves resulting from the choline-supplemented embryos were consistently 17-20 kilograms heavier at weaning. In the feeding experiment presented at the Florida Ruminant Nutrition Symposium, Dr. Sagheer fed rumen-protected choline to beef cows one day before AI through seven days post-AI, spanning ovulation, fertilization, and the first seven days of embryo development. In contrast to the in vitro studies, calves born to cows supplemented with choline during the peri-conception period were lighter at weaning than control calves. The panel discusses potential mechanisms of action for these results, including choline’s role as a methyl donor potentially impacting the epigenetic programming of the embryo. (3:25)
Dr. Hansen explains that during embryonic or fetal development, some key regions of DNA get methylated or unmethylated and that gets inherited by the animal postnatally. His lab has looked at DNA methylation in calves derived from choline-treated embryos and found not just hypermethylation as one might expect but also hypomethylation. So, it’s unclear if those changes in DNA methylation are the cause of the phenotype or a result of the phenotype. Currently, the group is culturing embryos with and without choline, then will measure DNA methylation in the embryo. Another group of embryos from the same matings will be used to produce calves, and DNA methylation will be measured in the calves to ascertain how many DNA methylation sites got changed in the embryo that are conserved in the live calf. (12:18)
Dr. Sagheer notes that there is a lot of choline in the uterus, so it makes sense that providing choline to the embryo culture media has positive results. This also may explain why they saw negative results in the in vivo feeding experiment. (15:07)
Dr. Hansen would like to conduct similar experiments in dairy cows. He suspects if we could get more growth in dairy heifers, they’d be more likely to make it to the milking herd. He also wonders if choline-treated embryos influence the placenta to produce more placental lactogen and thus the cow produces more milk. The panel discusses some of the challenges of individually feeding choline to cows on a commercial dairy for seven days around the time of AI. (19:36)
Dr. Sagheer replicated the in vivo feeding experiment with some ewes and found that choline-supplemented ewes have more ewe lambs than ram lambs. Dr. Hansen was sure that was simply due to chance, so they repeated the experiment with a larger group of ewes and found the same result: 60% ewe lambs and 40% ram lambs from ewes fed choline during the peri-conceptual period. There was no effect on fertility, so the choline wasn’t killing off the male fetuses. Dr. Hansen wonders if the choline might be altering the time of ovulation. In cattle, there is some evidence that if you inseminate at the same time as ovulation, you’re slightly more likely to create a male fetus since Y-sperm are slightly smaller and may get up the reproductive tract more quickly. If ovulation is delayed, you’re slightly more likely to get a female fetus. No differences in birth weights or weaning weights were observed in lambs whose dams were supplemented with choline, but choline-supplemented dams had lambs with larger ultrasound ribeye areas. (23:53)
Dr. Zenobi gives an overview of his PhD research at the University of Florida feeding rumen-protected choline during the transition period. Heifer calves born to cows supplemented with choline during the transition period had increased growth rates and better immunity than control animals. (30:47)
Dr. Sagheer would like to investigate how feeding choline during the peri-conceptual period affects the uterine microenvironment. Most research measures blood metabolites, but it appears that uterine metabolites are much more highly concentrated. (33:51)
The panel wraps up with their take-home messages. (37:16)
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