"The United States is home to 95 million cattle, and changing what they eat could have a significant effect on emissions of greenhouse gases like methane that are warming the world."
"HAPPY, Texas — Randy Shields looked out at a sea of cattle at the sprawling Wrangler Feedyard — 46,000 animals milling about in the dry Panhandle air as a feed truck swept by on its way to their pens.
Mr. Shields, who manages the yard for Cactus Feeders, knows that at its most basic, the business simply takes something that people can’t eat, and converts it into something they can: beef. That’s possible because cattle have a multichambered stomach where microbes ferment grass and other tough fibrous vegetation, making it digestible.
“The way I look at it, I’ve got 46,000 fermentation vats going out there,” Mr. Shields said."