GAINESVILLE, Fla. – New research demonstrates that a dairy cattle supplementary feed made of flaxseed and pea protein could reduce methane emissions.

The supplementary feed is a mixture of lipids and proteins. Antonio Faciola, associate professor of ruminant nutrition at the University of Florida, said that feeding lipids, such as flaxseed, to ruminants helps to suppress methane production. Methane is produced in the rumen when partially digested food is fermented, creating gas. Adding lipids to a ruminant’s diet leads to a lower amount of fermentable organic matter because fats are not fermented in the rumen.

Additionally, fats lead to a higher production of propionic acid, a volatile fatty acid that consumes hydrogen gas, lowering the amount of hydrogen available for the formation of methane. Microorganisms in the rumen are also inhibited by dietary fats, affecting the amount of hydrogen released into the rumen.

However, just the addition of lipids or flaxseed is not enough. Previous studies have shown that supplementary flaxseed can reduce nutrient intake and digestibility, particularly fiber digestion. The addition of a blend of fats and pea protein can help protect the rumen and improve nutrient digestion.

In a laboratory experiment, Faciola and his group observed that the flaxseed and pea protein supplementary feed reduced methane production and improved fiber digestion. The experiment was conducted using a dual-flow continuous culture system, a fermentation system that simulates the rumen. With eight fermenters, the lab can simulate eight cows.

Researchers can add grinded feed and artificial saliva to the fermenters and observe the digestion process of different ingredients. By measuring how fermentation changes with the addition of new ingredients, researchers can identify if methane production has decreased. This process helps save money and time; testing new feeds in live animals requires many cattle, and if researchers aren’t sure the feed is going to produce the effect they’re studying, they could waste time and money studying an entire herd.

Faciola said the results are a “win-win” for the environment and for cows.

“We are reducing methane, which is good for the environment. Also, when cows produce methane, it’s a loss of energy for them,” he said. “It’s good for the cows and the producers because instead of losing that energy, cows are retaining it, which could then be used for the production of milk for the animal, for example.”

Next, the research group will test the feed in a farm setting.

“We have a research farm at the University of Florida that hosts about 500 cows, and we want to do more of a fine-tuned experiment with the cows actually consuming this feed additive and see if we can replicate the results (of the recent study),” Faciola said. “Also, we want to see if there is any effect on milk production and composition.”

Reducing methane has been an important goal in cattle research for years because it is one of the most potent greenhouse gasses and contributes to rising temperatures across the globe. Faciola said that reducing methane production with little impact on the animal is important, and it’s even better if a solution for reducing methane could improve nutrient utilization or provide the animal with other nutrients, such as digestible fiber.

“It’s important to say that there’s no magic bullet (for reducing methane emissions),” he said. “If we as a society want to reduce methane, there are multiple things we need to be working on. It’s not going to be just one supplement, but maybe a combination of feed additives or supplements, and maybe even selecting cows that produce less methane or creating different farm management practices.”

Faciola added that his lab is investigating other feed supplements, such as algae, to reduce methane. Further, the lab is interested in improving nutrient utilization in ruminants.

“For example, one nutrient we spend a lot of time working on is nitrogen. We want to make sure we feed the least amount of nitrogen needed for cows to produce the most amount of milk, and we don’t want to waste any nitrogen,” he said. “If nitrogen is not used by the animal, it is excreted and that has environmental problems, too, such as algae blooms.”