During the transition period, a lot goes on “under the hood” so to speak that can be a drag on a cow’s efficiency, such as inflammation and decreased feed intake. However, supplementing choline in the diet can benefit a cow’s metabolism and play a role in the transport of nutrients across cell membranes, in the bloodstream and the mammary gland, and in synthesizing milkfat globules as well as the liver’s ability to export fat that accumulates during periods of weight loss in transition cows. From these benefits, years of research show that feeding supplemental rumen-protected choline during the transition period increases milk yield.
“A big collection of studies has shown, and I’m approximating, about a 5-pound-per-day increase in milk yield on average in early lactation cows,” says Dr. Barry Bradford, Michigan State University. “In a study we’re in the process of publishing now, we actually saw cows increase milk yield by about 9 pounds per day. So, it has an even bigger effect. But I’d say it’s been fairly consistent that there’s at least some milk response.”
In another recent experiment completed at the University of Wisconsin – Madison, Dr. Heather White also observed an increase during the transition period in relation to milk production.
“Supplementing rumen-protected choline during the transition period resulted in a 5.1-pounds-per-day advantage in energy-corrected milk [ECM] in the first 100 days of lactation,” White says. “This is consistent with a meta-analysis that reported a similar benefit in ECM. Interestingly, cows in our study were producing 30% more milk yield and 37% more ECM than the average of the meta-analysis, and we still observed a benefit.”
Not only did the choline increase milk production during the transition period, but it also showed improved benefits through the rest of lactation.
“In our study, we only fed choline through the first 21 days in milk and followed the cows past peak lactation. We actually got a continued increase in milk yield that didn’t really fall off over that window of time we evaluated,” Bradford says. “The fact that through 12 weeks of lactation cows were still making over 9 pounds per day more milk on average is a pretty huge effect. That’s nine weeks after we stopped feeding it. So, that’s pretty astounding.”
White also saw a similar response after supplementing choline for 21 days post-calving for 100 days of lactation, saying the increase in ECM was significant through the whole experimental period. Other work by Dr. José Santos from the University of Florida has also reported an increase in milk production (4.6 pounds per cow per day) that persisted over the entire 40-week (280 days) trial period.
“I think it's quite interesting [that] the response persists for many weeks after we stopped the treatment. It’s a very important finding, and we need to understand the mechanisms of it,” Santos says. “In general, things that have this carryover effect are typically linked to either better animal health or changes in mammary cell metabolism and survival. Either we extended the lifespan of the mammary cells, or we reduced the rate of cell death in the mammary gland.”
Both Bradford and White were most surprised that cows supplemented with prepartum rumen-protected choline also had greater colostrum yields, while maintaining quality.
“The study we just completed actually showed an 80% increase in colostrum yield,” Bradford says. “This has been really interesting to talk with producers about. I know people who have tried choline for the first time because of this potential to improve colostrum yield, and several of them circled back to me six months later and said it appeared to really help their fall colostrum shortfall problems.”
“This was an exciting finding and has value on-farm since colostrum is so critical for calf success,” White says. “Prepartum rumen-protected choline-treated cows had 4.3 pounds more colostrum yield with an average colostrum quality greater than 24.6 percent Brix score.”
Another important finding that Santos says often gets overlooked is that cows respond to rumen-protected choline irrespective of their body condition score when they start treatments during the pre-partum period.
“A lot of people think choline is a nutrient that should be fed only to fat, overconditioned cows,” Santos says. “This is a dogma that needs to be abolished from the industry because even if a cow has low body condition score, in terms of increase in milk production, she too responds to supplementing rumen-protected choline.”
Santos says nutritionists and producers should look at choline like we look at other nutrients. It should be part of the diet as a required nutrient for cows the same way we look at vitamins, minerals and amino acids.
“Every farm needs to do return on investment calculations for their situation, but in almost all cases, the milk yield benefits of choline pay for and justify the supplementation,” White says. “That means benefits to long-term milk production as well as colostrum and calf growth are bonus benefits.”
“With the new data in the last five years, if you’ve avoided choline in the past because you didn’t think you had metabolic issues, it’s worth looking again at the colostrum and milk yield data because it may be worth feeding simply as a boost to productivity and early lactation,” Bradford says.
“As with all rumen-protected products, there is variation in efficacy by product, so having the research is important,” White says.
