Hristov and his team study ways to reduce those emissions, so they have gotten very good at quantifying the amount their cows exhale. Prompted by some extra snacks, cow number 2050 ducks her head into a hooded machine that records the amount of methane, hydrogen, and carbon dioxide in her burps. During experiments, the scientists take eight measurements from each cow over several days. In a few months, this gives a snapshot of just how much methane the animals churn out -- and whether particular interventions work to slash that pollution.
One way to reduce the environmental impact of cow digestion is to chemically block the creation of methane in the gut. Hristov's group has been testing an inhibitor made by DSM Nutritional Products that is added to cow feed to do just that. It's called 3-nitrooxypropanol, or 3NOP, and prevents an enzyme in bacteria from powering the last step of methane formation.
So far, the compound appears to work. In Penn State's study, which was partially funded by DSM, methane emissions fell by 30 percent, compared to controls. The decrease persisted for the entire 12-week period the cows were on the drug, and milk production didn't suffer. Hristov, who previously evaluated a variety of natural herbs and oils for similar effects, sees 3NOP as a breakthrough.