The Feedlot's Footprint
by Troy Smith
We won't argue whether global warming is occurring as a result of the buildup of "greenhouse gases" largely attributable to the combustion of fossil fuels and other human activity. We can agree that lawmakers are under pressure to adopt climate change legislation. That's enough to focus attention on the so-called carbon footprint of all industries, including agriculture.
According to Environmental Protection Agency (EPA) statistics, agriculture is responsible for only 6.4% of all U.S. greenhouse gases. Still, because domestic livestock are responsible for about half of agriculture's share, livestock production comes under considerable scrutiny. Since 65% of livestock emissions are attributed to beef cattle, the beef industry must seem an easy target of criticism.
Terry Mader says that criticism tends to ignore the big picture. The University of Nebraska animal science researcher and extension beef specialist calls the beef industry's contribution to greenhouse gas emissions and its overall environmental footprint pretty small compared to other human activities and natural processes occurring on the planet. According to Mader, evaluating the environmental friendliness of any type of production system must consider resource availability and system efficiencies.
"The carbon footprint, per unit of production, has a close relationship to efficiency of production," Mader states. "In life-cycle analyses, the carbon footprint of beef cattle production today is 84% of what it was in 1977, largely due to increases in efficiency."
Put another way, it means four animals now yield the same amount of beef that, 35 years ago, required five animals to produce. It takes fewer animals, using less feed, less water and less land, to produce as much and more beef. Improving efficiency of production makes particularly good business sense when it's also good for the environment.
Mader says finishing cattle on grain is an example of improved efficiency of production that has reduced the beef industry's footprint. When compared to a fiber-based (grass-fed) finishing system, a grain-based (starch) finishing system produces roughly half the amount of greenhouse gases, which in the case of ruminant digestion is mostly methane. While he is not opposed to grass-finished beef, Mader says the evidence refutes any claims that it is "better" for the environment.
"From a greenhouse-gas-production standpoint, grass-fed beef is not as environmentally friendly," Mader says. "Cattle finished on forage produce more greenhouse gas than cattle on a starch diet. It can be lowered by increasing the quality of forage digested, but greenhouse gas production is still significantly higher than for grain-finished animals."
Mader also notes how cattle feeding technologies used to increase the efficiency beef cattle finishing systems help make the industry's footprint smaller. Feed additive ionophores increase the efficiency of rumen digestion and reduce emissions of greenhouse gases.
A fair amount of attention is directed to the amount of water used in beef cattle production. Certainly, water usage is a part of the industry's impact on the environment. However, Mader calls publicized claims stating production of each pound of beef requires more than 1,800 and even up to 2,500 gallons of water are "clearly exaggerated." He cites objective analysis, by the University of California–Davis, suggesting 441 gallons are required per pound of boneless beef.
"I'm pretty comfortable with that number," Mader states. "About 2% of that is used in the feedlot, and 1% during processing. Only 4% of total water used in beef production is actually consumed by animals. Ninety-five percent is irrigation water used to produce feed, including irrigated pasture."
Objective evaluation must consider that a significant portion of water for irrigation and other uses is recycled. Water scarcity is a growing concern, and Mader says probably too much is wasted. While efforts to conserve water use are warranted, the amount required represents a small part of the beef industry's footprint.
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