In a series of laboratory experiments and a live animal test, an oregano-based supplement not only decreased methane emissions in dairy cows by 40 percent, but also improved milk production, according to Alexander Hristov, Penn State University associate professor of dairy nutrition. Daily milk production increased nearly three pounds for each cow during the trials.
“Since methane production is an energy loss for the animal, this isn’t really a surprise,” Hristov says. “If you decrease energy loss, the cows can use that energy for other processes, such as making milk.”
Hristov first screened hundreds of essential oils, plants and various compounds in the laboratory before arriving at oregano as a possible solution. During the experiments, oregano consistently reduced methane without demonstrating any negative effects.
Following the laboratory experiments, Hristov conducted an experiment to study the effects of oregano on lactating cows at Penn State’s dairy barns. Follow-up animal trials are currently under way to verify the early findings and to further isolate specific compounds involved in the suppression of methane.