Depiction of the livestock industry as a major emitter of greenhouse gas doesn’t usually consider its role in converting forages from marginal lands into useful protein for human consumption.

As well, it seldom takes into account the productivity improvements, for dairy in particular, in developed countries. The U.S. used to have 25 million dairy cows. Now it has nine million but they produce 60 percent more milk than the 25 million did, Mitloehner said.

On the beef side, the U.S. used to have 140 million cattle and now 90 million animals produce the same amount of beef. It now produces 18 percent of the worlds’ beef with eight percent of the world’s beef herd.