Washington State University news release
Discussion of the environmental impact of animal agriculture is very different when you talk in terms of productivity instead of individual animals, according to one of the newest members of the Washington State University Department of Animal Sciences.
"You can't just talk about ‘the cow,'” said Jude Capper, assistant professor of animal science. "We have to think about it on an output basis, whether it's milk, beef, pork or poultry. From 1944 to 2007, the carbon footprint of the cow has doubled, but during that same time period, the carbon footprint per gallon of milk has decreased by more than two-thirds.”
Capper said milk production has grown from approximately 5,000 pounds per cow in 1944, when there were approximately 25.6 million dairy cows in the United States, to approximately 20,000 pounds per cow in 2007, when there were just 9.2 million dairy cows in the nation.
She attributes this increased sufficiency to advances in nutrition, genetics and management that allow cows to perform to their fullest potential. For example, rbST, a protein hormone that increases milk production allows enough milk to be produced to fulfill demand using fewer cows. That reduction in animals alone has had a huge environmental benefit, Capper said, especially in terms of reducing methane and carbon dioxide emissions associated with global climate change.
"For example, if we produce 10 billion pounds of milk from cows given rbST, it's like taking 112,000 cars off the road or planting 83.5 million trees,” she said. "The bottom line is if we improve productivity, we reduce our carbon footprint per gallon of milk.”
With a finite amount of land -- and a shrinking amount dedicated to agriculture -- as well as a rapidly growing population, Capper said the only way to feed the planet is through innovation and technology that increases efficiency and productivity. "Another consideration is that income is rising in developing countries such as China and India; when people have more money, they buy more milk, meat and eggs,” she said. "About 70 percent of the required increase in food production will have to come from technological advances.”
Capper noted that there is a perception that extensive livestock systems, such as grass-fed beef, are more environmentally benign than intensive systems, such as corn-fed beef. That, she said, in part is due to a report issued in 2006 by the United Nations called "Livestock's Long Shadow.” The main conclusion of that report was that livestock production accounts for 18% of global greenhouse gas emissions.
The report also concluded the livestock industry needed to become more efficient, to accept the industrialization of livestock production and that extensive livestock production will continue to exist where appropriate. Capper said the conclusions are sound, "but they all were totally overshadowed by the 18% figure.”