Cattle and beef production have been in the crosshairs of environmental activists for many years. But cattle became an even bigger target last year when the United Nation’s Food and Agriculture Organization issued a report stating that “cattle-rearing generates more global warming greenhouse gases, as measured in CO2 equivalent, than transportation.”

Animal-rights activists immediately used the U.N. report to argue that to save the planet, we should all become vegetarians.

Specifically, the U.N. report claims that the livestock sector accounts for 9 percent of carbon dioxide deriving from human-related activities, and 37 percent of all human-induced methane, which has 23 times more warming potential as carbon dioxide.

The U.N. report also said livestock now use 30 percent of the earth’s entire land surface, including 33 percent of the global arable land used to produce feed for livestock.

Despite gaining a lot of airtime and headlines from most of the national news media, the U.N. report also received a lot of criticism — much of that for inaccuracies in the data. And, besides disputing the U.N. report’s findings, livestock groups are beginning to show how ruminants can have a positive impact on the environment.

Talking points

While the United Nation’s Food and Agriculture Organization’s report, “Livestock’s Long Shadow — Environmental Issues and Options,” claims that 18 percent of the world’s carbon dioxide comes from cattle, data from the U.S. Environmental Protection Agency suggests otherwise. According to Karen Batra, director of Public Affairs for the National Cattlemen’s Beef Association, EPA data says animal agriculture does not contribute significantly to U.S. production of carbon dioxide. “EPA data shows that livestock contribute less than 2.4 percent of total U.S. greenhouse emissions, while fossil fuel combustion contributes 80 percent.”

  • In EPA’s April 15, 2007 report, “Inventory of Greenhouse Gas Emissions and Sinks: 1990-2005,” the EPA does not even list livestock as a concern in the United States with regard to carbon dioxide emissions.
  • Additionally, the EPA says that from 1990 to 2005, methane emissions from beef cattle operations have declined by 3 percent due to the decreasing population of beef cattle and improvements in feed quality.
  • By far, the EPA says, the largest emitter of methane gases is solid waste landfills which account for 24 percent of all methane emissions.
  • The U.N. report claims that livestock contribute 37 percent of human-induced methane, but the EPA says animal agriculture accounts for 27 percent of U.S. methane emissions, and methane accounts for less than 8 percent of total greenhouse gases.
  • Overall, the EPA says, from 1990 to 2005, emissions of methane from all sources decreased by 11.5 percent.

Although the EPA’s data is specific to the United States, Dr. Martin J. Hodson, principal lecturer in environmental biology at Oxford Brookes University, Oxford, England, says cattle are directly responsible for a relatively small proportion of global warming. However, indirect effects from cattle production coming from fertilizer manufacture, land use changes and processing are much greater. Still, Hodson says cattle’s global warming footprint is not as heavy as environmentalists claim.

  • Methane is responsible for 24 percent of anthropogenic global warming.
  • Of that, ruminants are responsible for 26.4 percent of methane.
  • So, ruminants are directly responsible for 6.3 percent of global warming.

Hodson says that a major problem is that the largest share of methane production is from poor countries and livestock fed on poor-quality feed. Methane from cattle can be reduced by:

  • Tweaking diet and genetics.
  • Increasing the digestibility of feedstuffs.
  • Advanced technologies in development, such as stimulation of certain bacteria to decrease hydrogen production, decreasing certain protozoa and vaccination to reduce methanogens.

Walking points

Feeding practices can reduce methane production from cattle, according to research at the University of Manitoba. Animal scientists Dinah Boadi and Karin Wittenberg say that when animal production efficiencies are improved — through proper nutrition, management, reproduction or genetic selection — the amount of feed required to maintain an animal is reduced by the diversion of more feed energy to production. As a result, there’s a drop in methane per unit of meat or milk produced. Boadi and Wittenberg suggest the following to reduce methane production.

  • Test feed and balance rations to suit the stage of production of animals.
  • Manage bunk feeding to prevent under or overfeeding of animals.
  • Maintain proper health, efficient reproduction and genetic selection.
  • Use production enhancing agents such as implants. Improved animal productivity reduces methane production per unit of product by 25 to 30 percent.
  • Use high-quality forages (such as immature forages and legumes) to increase feed efficiency and reduce methane production by 20 percent.
  • Grind or pellet low-quality forages to improve utilization by cattle, which can decrease methane production per unit of feed intake by 20 to 40 percent.
  • Use of ionophores improves feed efficiency and reduces methane production.
  • Add fats or oils to diets of high production animals. Feedlot trials at University of Manitoba suggest that adding 4 percent canola oil to high concentrate diets can reduce methane production by 33 percent.

Cattle producers can also help the environment through better management of rangeland and pastures. According to Holistic Management International, a non-profit organization formed to help farmers and ranchers enhance the efficiency, natural health, productivity and profitability of their land, cattle can help reverse global climate change with holistic management.

Specifically, holistic management of pasture and rangeland involves controlled grazing — grazing land at a high stocking rate for a short period of time. Controlled grazing leads to more productive cows and greater liveweight gains per acre, providing producers with increased profits and reducing methane emissions per pound of beef produced.

Controlled grazing also increases ability of the pastures to act as a sink for carbon dioxide. As pasture quality improves with controlled grazing, carbon builds up in the soil and plant biomass, reducing the total amount of carbon dioxide in the atmosphere. This is often referred to as carbon sequestration.

Advantages of controlled grazing management compared with traditional, continuous grazing includes:

  • Increased animal production per acre.
  • Improved botanical composition of pasture (increased legumes).
  • Improved yield and monthly distribution of forage.
  • Improved distribution and recycling of nutrients from animal manure and reduced mechanical handling.
  • Improved soil conservation and water quality.