What to Feed Cows, and What to Do about Belching?

Shortly after drafting the earlier post on feeding cattle, I came across “Spicing up the Menu” an article in the September 24, 2010 issue of Science magazine. It reported the finding by Pennsylvania State University scientists that feeding oregano to cows as part of the regular diet can cut production of methane nearly in half, and boost milk production as well. Methane is a powerful greenhouse gas, and belching by cattle and other ruminants is a significant global contributor to global warming. In their experiment cows were fed one pound of oregano as part of their diets. That seems like an awful lot of oregano to us, but perhaps continued research will find more abundant foods that work as well. Or, perhaps identification of the chemical mechanisms at work could lead to other methane-reducing diets. So, we have one more bit of evidence that feeding cows is a bigger deal than we had thought.

This EPA published chart above depicts the relative sources of atmospheric methane. The contribution made by belching cattle is shown by the light green slice of pie labeled "enteric fermentation"