(August 5, 2015) A
supplement added to the feed of high-producing dairy cows reduced methane
emissions by 30 percent and could have ramifications for global climate change,
according to an international team of researchers.
In addition, over the course of the 12-week study conducted
at Penn State's dairy barns, cows that consumed a feed regimen supplemented by
the novel methane inhibitor 3-nitrooxypropanol -- or 3NOP -- gained 80 percent
more body weight than cows in a control group. Significantly, feed intake,
fiber digestibility and milk production by cows that consumed the supplement
did not decrease.
The findings are noteworthy because methane is a potent
greenhouse gas. The U.S. Environmental Protection Agency estimates that methane
from livestock makes up 25 percent of the total methane emissions in the United
States. Globally, according to the United Nations' Food and Agriculture
Organization, animal agriculture emits 44 percent of the methane produced by
human activity.
Fermentation in the rumen -- one of the four stomach
chambers of livestock such as cattle, sheep and goats -- generates the methane,
as a result of microorganisms that aid in the process of digestion. The animals
must expel the gas to survive. The 3NOP supplement blocks an enzyme necessary
to catalyze the last step of methane creation by the microbes in the rumen.
It was important to conduct the study under
industry-relevant conditions, said lead researcher Alexander Hristov, professor
of dairy nutrition. The researchers published their results in a recent issue
of the Proceedings of the National Academy of Science.