Greenhouse Gas Emissions of Beef Cow-Calf Grazing Systems in Uruguay

Abstract

<p>Evaluating greenhouse gas (GHG) emissions at farm level is an important tool to mitigate climate change. Livestock account for 80% of the total GHG emissions in Uruguay, and beef cow-calf systems are possibly the largest contributors. In cow-calf grazing systems, optimizing forage allowance and grazing intensity may increase pasture productivity, reproductive performance, beef productivity, and possibly reduce GHG emissions. This study estimated GHG emissions per kg of live weight gain (LWG) and per hectare from 20 cow-calf systems in Uruguay, with different management practices. The GHG emissions were on average 20.8 kg CO<sub>2</sub>-e.kg LWG<sup>-1</sup>, ranging from 11.4 to 32.2. Beef productivity and reproductive efficiency were the main determinants of GHG emissions. Five farm clusters were identified with different productive and environmental efficiency by numerical classification of relevant variables. Improving grazing efficiency by optimizing the stocking rate and forage production can increase beef productivity by 22% and reduce GHG emissions per kg LWG by 28% compared to “low performance” management. Further improvements in reproductive efficiency can increase productivity by 41% and reduce GHG emissions per kg LWG by 23%, resulting in a “carbon smart” strategy. However, the most intensified farms with highest stocking rate and beef productivity, did not reduce GHG emissions per kg LWG, while increased GHG emissions per ha compared to the carbon smart. This analysis showed that it is possible to simultaneously reduce carbon footprint per kg and per ha, by optimizing grazing management. This study demonstrated that there is high potential to reduce cow-calf GHG emissions through improved grazing management.</p>

The combined effects of afforestation and grazing on Uruguayan grassland vegetation at multiple spatiotemporal scales

“…We refer to these dates as Spring 1 (0 months after exclosures were established), Autumn 1 (6 months after exclosures were established), Spring 2 (12 months after exclosures were established), and Autumn 2 (18 months after exclosures were established). Cattle grazing continued in the grazed areas throughout the study; livestock (primarily Hereford cattle) were free to roam throughout the year and between forest and grassland habitats [while we do not have specific stocking rates for our sites, in general, stocking rates for beef cattle in Uruguay are 0.55 livestock units ha -1 (Becona et al 2014)]. …”

Proceedings of the 10th International Symposium on the Nutrition of Herbivores

“…The use of different management practices has shown that there is great potential to reduce greenhouse gases (GHG) emissions produced by livestock, through improved grazing management (Becoña et al, 2014). Recently, new management technologies of forage allowance in rangeland have shown promising results in beef production per unit area (Soca et al, 2013), but the impact on relevant environmental variables such as methane emissions (CH 4 ) has not been quantified yet.…”

A generic method to analyse yield gaps in feed-crop livestock systems

“…Data for an average, pasture-based farm in Uruguay were adopted from Becoña et al (2014). Cattle grazed natural pasture year-round, and concentrate supplementation was negligible (Becoña et al, 2014).…”

“…Cattle grazed natural pasture year-round, and concentrate supplementation was negligible (Becoña et al, 2014). The cattle breed was not mentioned explicitly for farms in Uruguay.…”

“…Hereford cattle were selected subsequently, because the Hereford breed is the most common beef breed in Uruguay (Table A1). The diet under potential production was high-quality grass silage (metabolisable energy (ME) content = 11.1 MJ per kg DM (dry matter)) and the diet under resource-limited production corresponded to the average pasture quality (ME content = 8.6 MJ per kg DM) (Becoña et al, 2014). Diets were assumed to be available ad libitum under potential and resource-limited production.…”