The environmental impact of beef production in the United States: 1977 compared with 2007

Abstract

Consumers often perceive that the modern beef production system has an environmental impact far greater than that of historical systems, with improved efficiency being achieved at the expense of greenhouse gas emissions. The objective of this study was to compare the environmental impact of modern (2007) US beef production with production practices characteristic of the US beef system in 1977. A deterministic model based on the metabolism and nutrient requirements of the beef population was used to quantify resource inputs and waste outputs per billion kilograms of beef. Both the modern and historical production systems were modeled using characteristic management practices, population dynamics, and production data from US beef systems. Modern beef production requires considerably fewer resources than the equivalent system in 1977, with 69.9% of animals, 81.4% of feedstuffs, 87.9% of the water, and only 67.0% of the land required to produce 1 billion kg of beef. Waste outputs were similarly reduced, with modern beef systems producing 81.9% of the manure, 82.3% CH(4), and 88.0% N(2)O per billion kilograms of beef compared with production systems in 1977. The C footprint per billion kilograms of beef produced in 2007 was reduced by 16.3% compared with equivalent beef production in 1977. As the US population increases, it is crucial to continue the improvements in efficiency demonstrated over the past 30 yr to supply the market demand for safe, affordable beef while reducing resource use and mitigating environmental impact.

Diet effects on urine composition of cattle and N2O emissions

“…Similar improvements in efficiency and reduction of N excretion per unit product have been shown in other dairy and beef cattle production systems (e.g. Capper, 2011). Improvements in the production efficiency may reduce animal N waste per unit product; however, if this coincides with increased imports of concentrate and fertilizer N, N efficiency at farm level may actually decrease because of higher losses at plant and soil level.…”

Optimizing diet and pasture management to improve sustainability of U.S. beef production

“…The model predicted water use at 1281 L/kg HCW beef which was in the range of previous studies estimating water use. This value was greater than some previous estimates of beef water use in the U.S. or Australia (Table 8; Capper, 2011Capper, , 2012Ridoutt et al, 2011) likely because of irrigated pasture use. A different water foot printing methodology estimated substantially more water use attributable to beef (Hoekstra and Chapagain, 2007) because different water sources (i.e.…”

“…A historical comparison of the U.S. beef industry indicated 16.3%, 12.1%, 33% reductions in GHG emissions, water use and land use over a 30 year period (Capper, 2011). The reductions modeled in our study represent an instant change in management given the feedstuffs available today.…”

“…In Capper (2011), the 30 year changes in environmental impact were associated with reducing finishing time while concurrently increasing finishing weight. In this assessment, finishing time and weight were constrained and only dietary composition was allowed to vary.…”

“…The reductions modeled in our study represent an instant change in management given the feedstuffs available today. Assuming that the trend demonstrated in Capper (2011) continues and new efficiency-improving technologies become available over the next several years, ample opportunities will exist to improve future beef sustainability. Models, such as the one employed in this study, can be used to assess optimal adoption of technologies to ensure economic viability, social acceptability and improved environmental impact.…”