Arm & Hammer Animal and Food Production

From Concept to Common Practice: 30 Years for Feeding Bypass Fat

It’s difficult to think about formulating lactating cow dairy diets today without including a source of rumen-protected fatty acids. Bypass fatty acids help increase available energy, which is extremely important to high-producing cows since energy demands exceed energy intake for the first 80 to 100 days postpartum.

But prior to 1986, and the introduction of MEGALAC® to the U.S. dairy market, bypass fat wasn’t even a ration consideration for most nutritionists and dairy producers.

The concept of feeding supplemental fatty acids to boost cow performance had been around since the 1930s. However, dairy researchers and producers struggled with how to overcome the negative impacts of feeding supplemental unsaturated fatty acids on rumen fermentation and fiber digestion, especially when rations contained high-quality forages and other ingredients that naturally include some fat.


“Fatty acids deliver about 2.25 times as much energy to the diet as starches and digestible fiber, but unsaturated fatty acids interfere with the rumen’s microbial fermentation process,” explains Dr. Kenneth Cummings, former director of animal research and technical service for Church & Dwight Company, the parent of Arm & Hammer Animal Nutrition.

Fatty acids are not fermentable, meaning they are not a source of energy for rumen microbes. In addition, unsaturated fatty acids are toxic to the microbes so as a defense mechanism, rumen microbes biohyrdogenate, or saturate, these fatty acids to a less toxic form, decreasing effectiveness of feeding supplemental fat.

But because it was long-known that fat was beneficial for animal performance in a number of areas, it wasn’t unusual for diets to contain supplemental fat sources like tallow or oilseeds, which can be helpful  to a certain point but will interfere with rumen fermentation past that point.

“Research had shown since the 1950s that supplemental fatty acids in rumen fermentation systems would alter rumen fermentation and when fed to dairy cows, would actually cause milk fat depression and other production challenges.” notes Dr. Don Palmquist, dairy nutrition professor emeritus, The Ohio State University. For instance, production of 4 percent fat-corrected milk tends to decrease linearly as unsaturation of fatty acids in supplemental fat sources increase.

Producers in Denmark had been successfully feeding supplement fat before the practice crossed the Atlantic Ocean. But the diet there often contained ingredients like fodder beets or barley straw that contained almost no fat, unlike rations in the United States with high levels of corn silage. Addition of fatty acids to those diets was not an issue due to the very low levels of fat is the rations.

Supplemental fat feeding theories advanced to include rumen-protected fatty acids by the 1970s, but activity remained largely contained to research settings.

Companion to Sodium Bicarbonate

In the early 1980s, Cummings had been tasked with finding complimentary dairy nutrition products for ARM & HAMMERTM Sodium Bicarbonate.

“We knew that fat was beneficial to dairy cows and set out to find ways to develop a protective coating around the fatty acids so that they would be able to bypass one part of the digestive system and released in another part so we could gain the most benefit from it,” he explains.

“We were brainstorming—along with Dr. Bill Chalupa at Penn State University and others—about various ways to create rumen protection for long-chain unsaturated fatty acids and searching for sources of rumen protected fatty acids,” says Cummings.

To this end, Cummings had been in contact with university researchers in the United States and Europe, as well as private companies like Volac in the UK, who were working on various fat-feeding nutrition theories and early product development. Although the concept had been studied for years, practical ways to deliver bypass fatty acids had yet to be developed to the point of commercialization.

After a bit of trial and error, the researchers discovered that the use of calcium oxide rather than calcium carbonate was the key to creating a stable reaction to create calcium salts or soaps of the fatty acids that would generate the most benefit to the cow. “In essence, we replicated the thousands-of-years old recipe for making soap in the cow’s digestive system,” says Cummings.

Bypassing the Rumen

This calcium soap protected the long-chain unsaturated fatty acids from biohydrogenation in the rumen and prevented the fatty acids from being soluble in the rumen and interfering with fiber digestion.

Meanwhile, Palmquist was also pursuing the development of a bypass fatty acids as a way to boost a cow’s energy needs while overcoming the challenge supplemental fat feeding posed to rumen fermentation.

Additional investigations led Palmquist to Europe, and ultimately to collaborations with Dr. Cummings, ARM & HAMMER and Volac.

Accidental Success

While the ultimate impacts of bypass fats on dairy nutrition are remarkable, the initial development of a commercially available source of rumen bypass fatty acids in the 1980s was somewhat of a happy accident.

“It’s not something we were looking for,” notes Palmquist. He had been interested in calcium salts of fatty acids since 1979. Investigations into long-chain fatty acids and the importance of fat in the diet (about 90 percent of the long-chain fatty acids in milk fat come from the diet) led to further research into the interaction between calcium fatty acids and fiber digestion.

Palmquist credits then graduate student Tom Jenkins, now professor emeritus, Clemson University, as a key collaborator in the process. “Tom’s in vitro studies did a nice job of showing how calcium salts of fatty acids would be beneficial in dairy nutrition,” says Palmquist. “But we couldn’t completely overcome the challenge of fiber digestion inhibition, even with the addition of calcium.”

By 1982, Jenkins and Palmquist were the first to feed preformed calcium salts to ruminants and definitively show rumen inertness1.A series of in vivo experiments in the ensuing years solidified their findings; eventually The Ohio State University patented calcium salts of long-chain fatty acids. And research continued into bypass fats.

Around the same time, Church & Dwight licensed MEGALAC rumen bypass fat from Volac, and formally launched the first commercial bypass fat product in the United States along with an entirely new feed ingredient category. To this day, on-farm trials and controlled university research consistently convince nutritionists and producers to include it in dairy rations.

Over the years, many competitive products have entered the market and the evaluation of fatty acid sources continues. Still, MEGALAC remains the most researched product with more than 54 peer-reviewed articles published—and calcium soaps of long-chain fatty acids remain the standard by which all other fat sources are compared.

“The bypass fat category has grown tremendously since the early days,” says Cummings.

Worldwide, more than 500,000 tons of bypass fats are consumed by livestock and production has expanded to include the United States, Europe and Asia.

“When you couple it with the impact of feeding rumen buffers, MEGALAC and the concept of feeding bypass fatty acids have made a heck of an impact on the entire dairy industry,” he concludes.

1 Palmquist DL, Jenkins TC. Calcium soaps as a fat supplementation in dairy cattle feeding. In Proceedings. XII Congress on Diseases in Cattle. 1982; 477 – 481.

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