Greenhouse gas emissions of Canadian beef production in 1981 as compared with 2011

Abstract

The present study compared the greenhouse gas (GHG) emissions, and breeding herd and land requirements of Canadian beef production in 1981 and 2011. In the analysis, temporal and regional differences in feed types, feeding systems, cattle categories, average daily gains and carcass weights were considered. Emissions were estimated using life-cycle assessment (cradle to farm gate), based primarily on Holos, a Canadian whole-farm emissions model. In 2011, beef production in Canada required only 71% of the breeding herd (i.e. cows, bulls, calves and replacement heifers) and 76% of the land needed to produce the same amount of liveweight for slaughter as in 1981. Compared with 1981, in 2011 the same amount of slaughter weight was produced, with a 14% decline in CH4 emissions, 15% decline in N2O emissions and a 12% decline in CO2 emissions from fossil fuel use. Enteric CH4 production accounted for 73% of total GHG emissions in both years. The estimated intensity of GHG emissions per kilogram of liveweight that left the farm was 14.0 kg CO2 equivalents for 1981 and 12.0 kg CO2 equivalents for 2011, a decline of 14%. A significant reduction in GHG intensity over the past three decades occurred as a result of increased average daily gain and slaughter weight, improved reproductive efficiency, reduced time to slaughter, increased crop yields and a shift towards high-grain diets that enabled cattle to be marketed at an earlier age. Future studies are necessary to examine the impact of beef production on other sustainability metrics, including water use, air quality, biodiversity and provision of ecosystems services.

A glimpse of the future in animal nutrition science. 1. Past and future challenges

“…In Australia, Wiedemann et al (2015), using life-cycle assessment analysis, concluded that from 1981 to 2010, the beef industry decreased GHG emission intensity by 14% (15.3 to 13.1 kg CO 2 equivalent/kg body weight) due to heavier carcasses, increased performance for grass-fed and feedlot animals, and improved survival rates. In Canada, Legesse et al (2016) indicated that increased average daily gain, improved reproductive efficiency, reduced time to slaughter, increased crop yields, and a shift toward highgain diets that enable cattle to grow faster were the main factors responsible for a decline of 14% in GHG emissions, 15% in N 2 O emissions, and 12% in CO 2 from fossil fuel in 2011 when compared with 1981 to produce the same cattle slaughter weight. Many of these assessments, however, did not include land use (e.g., production of grain to feed feedlot animals) and the direct land use change (i.e., deforestation for beef cattle pastures) or the dairy sector contribution to the meat production.…”

Estimating enteric methane production for beef cattle using empirical prediction models compared with IPCC Tier 2 methodology

“…The finishing phase is largely conducted in feedlots using high grain diets (≥ 80% of concentrate in diets, DM basis). Many different management practices and diets for growing and finishing cattle are used in Canada (Shepard et al 2015;Legesse et al 2016). As the focus of the current study was to explore variability and uncertainties in CH 4 prediction due to The production systems used for beef cows and steers are based on Legesse et al (2016) and presented in Figure 1.…”

“…Many different management practices and diets for growing and finishing cattle are used in Canada (Shepard et al 2015;Legesse et al 2016). As the focus of the current study was to explore variability and uncertainties in CH 4 prediction due to The production systems used for beef cows and steers are based on Legesse et al (2016) and presented in Figure 1. Each scheme was comprised of individual stages to account for daily changes in BW, diet composition, environmental conditions and management (grazing, confinement).…”

“…A yearling steer scenario was selected to allow for exploration of various types of diets (high-forage, pasture, and high-concentrate). According to Legesse et al (2016), this scenario represents about one-third of calf production in Canada. Simulations were conducted for Eastern and Western regions to reflect differences in diet ingredients and age at slaughter (22 and 21 mo, respectively).…”

“…The Canadian beef production industry is complex (Shepard et al 2015, Alemu et al 2016, Legesse et al 2016). In simple terms, the beef production system starts with breeding herds (cow-calf sector) that produce calves for subsequent backgrounding and finishing.…”