Research Roundup Column
The total carbon footprint (environmental impact) from producing 1 lb. of beef in 2007 was 14% less than in 1977, Washington State University (WSU) research concludes.
The research modeled the environmental impact of the entire 1977 U.S. beef herd, which produced 23.3 billion lbs. of beef from 38.7 million head of cattle slaughtered, compared to the 2007 beef herd, which produced 26.2 billion lbs. of beef from 33.7 million head. The environmental impact model used integrated resource inputs and waste outputs from animal nutrition and metabolism, herd-population dynamics and cropping parameters. A life cycle approach from the cow-calf operation to the feedlot to the slaughter plant was followed. Inputs included feedstuffs, water, land, fertilizer and fossil fuel. Outputs included beef product, manure and greenhouse gas emissions.
The total animal population required to produce 1 billion lbs. of beef in 2007 was reduced by 27% compared with 1977. This decrease in population size conferred reductions in total feed energy, feedstuffs and land use of 10%, 17% and 27%, respectively. Water use was reduced 15%, while fossil-fuel usage was reduced 11%. Methane and nitrous oxide gas emissions per billion lbs. of beef produced in 2007 was 17% and 13% less, respectively, than for an equivalent amount of beef produced in 1977. The environmental impact from modern beef production is clearly improving.
Additional research analysis conducted by WSU and Elanco Animal Health scientists compared the environmental impact and sustainability of corn-fed and grass-fed beef production systems. The analysis was based on resource requirements from weaning to slaughter of Angus x Hereford steers and included inputs of feedstuffs, pasture composition and quantity, land requirements, fossil fuel and fertilizer use.
Reduced growth rate of grass-fed steers (1.9 vs. 3.5 lbs./day) lengthened the finishing period from 237 to 438 days. Steers finished on pasture have additional daily maintenance energy requirement and total energy use.
In addition, grass-fed diets promote greater methane-gas production and emission than corn-fed diets. Total energy use, methane-gas production and land-area use to produce 1 lb. of grass-fed beef was 2.5, 2.8 and 13 times greater, respectively, than the amounts needed to produce 1 lb. of corn-fed beef. Per unit of beef produced, conventional feedlot feeding is more sustainable and environmentally sound.
The environmental benefits of the use of a growth-enhancing technology were estimated by Colorado State University scientists. Using published data on the increase in carcass weight and protein accretion from the use of ractopamine (a feed ingredient available for use in finishing cattle), the researchers calculated that 5.5% fewer feedlot cattle fed ractopamine (1.5 million head) would produce the same amount of beef if the technology were not used.
Further calculations reveal 1.7 million fewer beef cows and 310,000 fewer replacement heifers would be needed annually to supply the same amount of beef. The combined reduction in slaughter steer and heifers and beef cow and replacement heifers would reduce annual feed requirements by 18 billion lbs.
Thus, fossil fuel, water, land use, fertilizer and herbicide use related to crop and livestock production would also be reduced. Manure and greenhouse gas production would decline accordingly.
The commonly perceived notion that historical livestock production is more environmentally friendly is unfounded. Livestock producers should strive to communicate the benefits of modern livestock production and technology to consumers and environmentalists alike.
Full reports available at
• http://adsa.psa.ampa.csas.asas.org/meetings/2010/abstracts/0823.pdf - abstract # 1011
• http://adsa.asas.org/meetings/2010/abstracts/0683.pdf - abstract # W310
• http://adsa.asas.org/midwest/2010/2010MWAbstract.pdf - page 116.
Scott B. Laudert, Ph.D., is a beef cattle technical consultant and former Kansas State University Extension livestock specialist based in Woodland Park, CO. Contact him at 719-660-4473.