“It takes 7 to 8 pounds of feed to produce a pound of beef and 5½ to 6 pounds of feed to produce a pound of pork,” says Robert Lawrence, professor of environmental health sciences, health policy, and international health at the Johns Hopkins Bloomberg School of Public Health in Baltimore.
In fact, most of U.S. farming is devoted to growing animal feed. “About 60 to 70 percent of soybeans and a slightly higher percentage of corn goes for animal feed rather than as feed for humans or other uses,” Lawrence notes. The water and fossil fuels needed to grow all that grain and the sheer number of animals consumed in the United States cause considerable damage:
“It requires about 1,000 tons of water to produce a ton of grain,” explains Lawrence. “Worldwide, it’s estimated that 80 percent of groundwater from shallow and deep aquifers is used for agricultural purposes, and, increasingly, that purpose is irrigating crops for animal feed.” And it takes fuel to get that water.
“As we rely more and more on groundwater for irrigation in areas that aren’t getting enough natural rainfall, we need more and more energy to pump and distribute water to produce the feed.”
“As ruminants, cattle digest the cellulose in feed in their rumens,” explains Lawrence. That produces methane gas that the cattle get rid of either by belching or passing wind. And methane is a potent greenhouse gas. “It has 23 times the heat-trapping capacity of carbon dioxide,” says Lawrence.
“Molecule for molecule, nitrous oxide has about 200 times the heat-trapping capacity of carbon dioxide,” says Lawrence. “Nitrous oxide comes from the intense application of nitrous fertilizers for the soy and corn being grown for animal feed.”
“But worse than that, the soil is exposed and often tilled to prepare it for seeding for pasture,” says Lawrence. “As soon as you begin to turn over soil to create pastureland, the organic material that’s trapped in the topsoil is exposed to the oxygen in the air and carbon dioxide is released.” And then comes fertilizer. “Particularly in tropical areas, the soil is lacking in nutrients, and when you start fertilizing that land, nitrous oxide is released.”
“Big open cesspits can contain as much as three million gallons of urine and feces in a typical hog CAFO,” says Lawrence. (“CAFO” stands for concentrated animal feeding operation.) “A lot of anaerobic digestion goes on in the waste, which leads to methane production,” he adds. And using tarps to trap the methane “has been a big disappointment.”
It’s not just pigs. “The waste in big cattle feedlots can be properly composted, but it almost never is,” says Lawrence. “In a typical operation, the manure is just bulldozed into big mounds, so there’s a release of methane.”
“When animals in smaller numbers were grown on smaller farms, the feed was in the pasture or in the hay that was laid up for the winter,” says Lawrence. “Now we’ve moved animals into confinement, so we have to transport feed to them.” And that takes more fossil fuels.
Other reasons to save a cow: