ARS | Publication request: The carbon-footprint of cattle feeding: A North American perspective

Submitted to: American Society of Animal Science Proceedings
Publication Type: Proceedings
Publication Acceptance Date: November 22, 2012
Publication Date: N/A

Interpretive Summary: The Asian-Australian Animal Science Congress is held every other year in Asia or Australia. Average attendance is approximatley 2000 people, making it one of the largest attended conferences in the far east. Most cattle in Asia and Australia are grass- finished; however, the cattle feeding industry is growing in some countries. Environmental issues are of concern to the producers, and citizens of Asia and Asutralia. Dr. Cole will present a paper summarizing nutrition and managment techniques that can be used to minimize environmetal impacts of cattle production. The presentation, and manuscript includes reducing ammonia, and greenhouse gas emissions from cattle operations.

Technical Abstract: In contrast to much of the world, in North America, beef cattle typically spend a portion of their life in feedlots where they are fed diets high in grains and/or by-products. Feeding cattle nutritionally balanced, high-energy diets in confined feedlots can have several advantages over pastoral systems, however, there are also potential risks. The feeding of livestock in confinement leads to a concentration of feed nutrients into a relatively small geographic area. Accumulation of "excess" nutrients, and the extraneous losses of these nutrients to ground or surface waters, and the atmosphere, and removal of accumulated manure are significant environmental concerns to cattle feeders, and the general public. Direct and indirect emissions of ammonia (NH3) and GHG (nitrous oxide – N2O; methane – CH4; and carbon dioxide - CO2) are of particular concern. Nutrition and management practices can influence the quantity of nutrients excreted by the animal, as well as influence transformations, and movements of excreted nutrients and losses of GHG. A number of studies have estimated the C-footprint of the beef cattle industry in North American. Studies consistently demonstrate that the cow-calf herd represents the vast majority of the C-footprint. This is primarily because of the low reproductive rate of the cow herd. In general a beef cow will duplicate her own BW in an offspring or saleable product only about once every 12-18 months. In contrast, swine, poultry, and dairy cattle duplicate their weight in saleable product by 20 to 150 times each year. The C-footprint of cattle feeding is affected by factors such as grain processing method, use of by-products, and the interactions between these and other factors. Use of technologies such as steam flaking of grain may actually decrease the C-footprint by decreasing enteric methane emission, the quantity of corn required, as well as decreasing the quantity of manure produced. It appears that the effects of feeding by-products such as distillers grains on the C-footprint are dependent upon the concentration of by-product in the diet and the corn processing method used.