Biomass use, production, feed efficiencies, and greenhouse gas emissions from global livestock systems

Abstract

We present a unique, biologically consistent, spatially disaggregated global livestock dataset containing information on biomass use, production, feed efficiency, excretion, and greenhouse gas emissions for 28 regions, 8 livestock production systems, 4 animal species (cattle, small ruminants, pigs, and poultry), and 3 livestock products (milk, meat, and eggs). The dataset contains over 50 new global maps containing high-resolution information for understanding the multiple roles (biophysical, economic, social) that livestock can play in different parts of the world. The dataset highlights: (i) feed efficiency as a key driver of productivity, resource use, and greenhouse gas emission intensities, with vast differences between production systems and animal products; (ii) the importance of grasslands as a global resource, supplying almost 50% of biomass for animals while continuing to be at the epicentre of land conversion processes; and (iii) the importance of mixed crop-livestock systems, producing the greater part of animal production (over 60%) in both the developed and the developing world. These data provide critical information for developing targeted, sustainable solutions for the livestock sector and its widely ranging contribution to the global food system. global change | sustainability | GHG emissions | land use T he importance of the livestock sector as a user of natural resources, as a source of livelihoods, and as an engine of economic growth has been the focus of significant attention in the last decade (1-5). As the largest land-use system on Earth, the livestock sector occupies 30% of the world's ice-free surface, contributes 40% of global agricultural gross domestic product, and provides income for more than 1.3 billion people and nourishment for at least 800 million food-insecure people, all the while using vast areas of rangelands, one-third of the freshwater, and one-third of global cropland as feed. In the process, livestock can both contribute valuable nutrients for crops and be responsible for nutrient pollution and land degradation, and they can both provide critically important protein and micronutrients to human diets and contribute to obesity. The sector has many dualities, and the roles played by livestock change depending on location and circumstances. However, there is growing recognition that improving the environmental performance of livestock systems as well as establishing sustainable levels of consumption of animal-sourced foods, are essential for the sustainability of the global food system (5-7).Insufficient attention has been paid to the generation of livestock data at the level of detail required for elucidating their future role in attaining key global sustainability goals. Some of these goals are poverty reduction, food and nutritional security, ecosystem protection, mitigation of greenhouse gases (GHG), and adaptation to climate change, for example. To date, global integrated assessments have included incomplete representations, at best, of the livestock sector (8-11). So...

Herd-scale measurements of methane emissions from cattle grazing extensive sub-tropical grasslands using the open-path laser technique

“…Such extensive systems support large numbers of domestic ruminants but are characterised by low stocking rates and low animal productivity (Food and Agriculture Organization of the United Nations, 2006). They contribute a significant proportion of global livestock methane (CH 4 ) emissions (Herrero et al, 2013). Holechek (2013) estimated that global rangelands provide~70% of ruminant feeds, implying that they contribute at least as much of global ruminant CH 4 emission.…”

Simulation of enteric methane emissions from individual beef cattle in tropical pastures of improving quality: a case study with the model RUMINANT

“…The mechanistic model RUMINANT The rumen dynamics model developed and described by Herrero et al (2013) (RUMINANT) is used for this study. A detailed description of the equations and coefficients embedded in the model of Herrero et al (2013) is provided in the studies of Illius and Gordon (1991) and Sniffen et al (1992).…”

“…A detailed description of the equations and coefficients embedded in the model of Herrero et al (2013) is provided in the studies of Illius and Gordon (1991) and Sniffen et al (1992). Model input variables consists of current and target live body weights, maximum milk production and daily weight gain.…”

Using a One Health approach to assess the impact of parasitic disease in livestock: how does it add value?

“…Livestock contribute substantially to human wellbeing, contributing 40% of global agricultural gross domestic product, and providing an income for more than 1.3 billion people (Herrero et al, 2009), whilst nourishing at least 800 million of the worlds most food insecure people (Herrero et al, 2013). However, increased numbers of livestock have been accompanied by the expansion of arable and pasture land.…”

“…A key driver of productivity, total resource use, and greenhouse gas emissions in intensive farming systems is the efficiency in the conversion of feed to livestock products (Herrero et al, 2013). It is well established that endemic parasitic diseases in livestock reduce feed--conversion efficiency, therefore mitigating these diseases in a cost--effective manner could improve the sustainability of livestock production systems.…”