Effect of changes in management practices and animal performance on ammonia emissions from Canadian beef production in 1981 as compared with 2011

Abstract

The present study compared ammonia (NH3) emissions from Canadian beef production in 1981–2011. Temporal and regional differences in cattle categories, feed types and management systems, average daily gains, carcass weights, and manure handling practices were considered. A scenario-based sensitivity analysis in 2011 estimated the impact of substituting corn dried distillers’ grains with solubles (DDGS) for grain in feedlot diets. On average, 22% of the total nitrogen (N) intake was lost as ammoniacal nitrogen (NH3-N) in both years. Manure emission sources were consistent across years, averaging 12%, 40%, 28%, and 21% for grazing, confinement, storage, and land spreading, respectively. Emissions per animal in 1981 and 2011 were 16.0 and 18.4 kg NH3 animal−1 yr−1, respectively. On an intensity basis, kilogram of NH3 emitted per kilogram of beef decreased 20%, from 0.17 in 1981 to 0.14 in 2011. This reduction was attributed to increases in reproductive efficiency, average daily gain and carcass weight, and improved breeding herd productivity. In 2011, substituting DDGS for grain in feedlot diets increased total NH3 emissions and losses per animal. Although addition of by-products from the bioethanol industry can lower diet costs, it will be at the expense of an increase in NH3 emissions.

Modelling environmental impacts associated with the removal of productivity-enhancing technologies from Canadian feedlots: a case study

“…Daily NH 3 emissions from confined cattle housing (NH 3emissions, h ; Legesse et al 2018b;Aboagye et al 2022) were estimated as: NH 3emissions, h = TAN excreted × 0.9 × Feedlot temp adjustment × 17/14 (4) Feedlot temp adjustment = 1.041 average temp /1.041 17.7 (5) Can. J. Anim.…”

“…A number of modelling studies have estimated the environmental impacts associated with the cattle industry in the United States (Beckett and Oltjen 1993;Hristov et al 2011;Stackhouse-Lawson et al 2012;White and Hall 2017) and Canada (Ominski et al 2007;Beauchemin et al 2010;Alemu et al 2017a;Legesse et al 2016Legesse et al , 2018aLegesse et al , 2018b. Potential strategies to reduce the environmental footprint associated with beef production, includes genetic improvement (Basarab et al 2013), reducing days on feed (DOF) prior to slaughter (Capper 2012), increasing breeding stock longevity, improving weaning rates, conversion of crop land to pasture (Beauchemin et al 2011), and diet modification, including feeding of higher quality forages (Guyader et al 2017) or dried distillers grains (Hünerberg et al 2014).…”

The role of livestock in sustainable food production systems in Canada

“…Despite the comparatively lower emissions compared to some other sectors, considerable effort has been expended in estimating the environmental footprint of beef, dairy and eggs. Over a 30-year time period , Canadian beef producers have reduced GHG emissions (kg -1 carcass) by 15% (Legesse et al 2016), ammonia emissions by 17% (Legesse et al 2018a), water use by 20% (Legesse et al 2018b), while using 24% less land (Legesse et al 2016). Similarly, in another study conducted in the US, the nation's beef industry in 2007 required 30% fewer beef cattle, 22% less water, and 33% less land, with a 16% decline in the carbon footprint per kg of beef than in 1977 (Capper 2011).…”

Mitigation of greenhouse gas emissions from beef cattle production systems

“…Animal productivity is important for beef farm profitability and is positively related to reductions in GHG emissions (Åby et al, 2014). The environmental impact of improved carcass production has been investigated by a number of studies (Thornton & Herrero, 2010;Desjardins et al, 2012;Legesse et al, 2016;Murphy et al, 2017;Legesse et al, 2018). Murphy et al (2017) showed decreased emission intensity when reducing age at slaughter, while increased average daily gain (ADG) reduced the emission intensities of Irish beef production systems (Casey & Holden, 2006;Crosson et al, 2010).…”

“…Murphy et al (2017) showed decreased emission intensity when reducing age at slaughter, while increased average daily gain (ADG) reduced the emission intensities of Irish beef production systems (Casey & Holden, 2006;Crosson et al, 2010). The emission intensities from Canadian beef production have decreased from 1981 to 2011 due to improved reproduction efficiency, increased ADG, increased slaughter weight, reduced age at slaughter, and use of high grain diets that enabled slaughtering at a younger age (Legesse et al, 2016(Legesse et al, , 2018.…”