Refinement of techniques and evaluation of options to reduce greenhouse gas emissions from ruminant production systems in Brazil and the UK

Methane emissions from ruminant livestock make up a significant proportion of the emissions of greenhouse gas emissions from agriculture. Reductions of emissions from this sector depend heavily on improvements in measurements on which to base mitigation strategies. The UK and Brazil are currently developing state -of-the -art facilities for the measurement of methane from livestock using a range of experimental approaches. As a consequence o f the high priority linked to this research, the science is developing rapidly, and international collaboration is a highly affective route to accelerating progress.
Development and standardisation of methods for measuring methane emissions under a wide range of conditions (grazing/indoors; high- and low-production intensity; feed/fertiliser imported into the systems or not) is the first issue to consider in this project. This requires exchange of researchers to gain experience of the different methods and production systems. Researchers will work alongside ongoing studies using the various methane emissions measurements systems in:
UK: respiration chambers; 'sniffer' hoods; laser methane gun; and methane proxies (work on methanogen membrane lipids and hydrogen isotopic fractionation).
Brazil: extensive systems and crop-livestock-forestry systems measurements (enteric methane using SF6 tracer technique, soil N2O, CH4 and CO2 using static closed chamber method) in the Pecus Network.
Specific objectives of the work on methane methods are:

Standardisation of methodologies for measuring methane emissions from housed and grazing cattle in the UK and Brazil. Bringing together independent evaluations of techniques conducted in each country to identify potential improvements. Output: review paper

Identifying potential for new methane measurement approaches for use with free-grazing cattle. This will involve reviewing techniques currently used with grazing cattle (sulphur hexafluoride; SF6) and other methods under development (mobile sensors and proxy techniques). Output: plan for a joint research programme to develop the approach.

Developing methods for combined measurements of heat stress and methane production - refining use of respiration chambers to move from 'GHG mitigation' to 'GHG adaptation' research. Output: technical report.
A second challenge that will be addressed is the fact that effects on methane emissions per cow may be negated when the full GHG costs associated with a particular treatment are taken into account. This requires a systematic approach to modelling methane emissions that takes account of wider emissions (e.g. in the production of feed and fertiliser used in the system). We will adopt a Tier 2 Emissions Framework modelling approach (with some Tier 1 values for carbon dioxide and nitrous oxide) to evaluate mitigation options from previous studies in each country. Output: modelling paper.

Brazil is the global leader in beef exports, with the second largest commercial herd in the world (212.8 million head). With very favourable soil, climate and area conditions, as well as increased use of advanced technologies, beef cattle account for 11% of the GDP of national agribusiness. In 2013, the production of bovine meat amounted to about 9.5 million tons, with exports reaching 1.5 million tons. The Centre-West and North regions are the fastest growing cattle raising areas, a trend that is likely to continue as the world struggles to meet the anticipated 60% growth in demand by 2050. Research is needed both to identify potential new mitigation strategies and to understand the wider greenhouse gas implications of changes in Brazilian agriculture. Brazil has identified this sector as critical to growth and prosperity and invested heavily in research capability. This collaboration will help Brazil make most progress from this investment.

There is a strong synergy between the UK and Brazil in livestock science and greenhouse gas research. The UK's long tradition in livestock science is matched by a large recent expansion of capability in Brazil, with many new opportunities and ideas under investigation. There are similar challenges facing researchers in each country - with high methane emissions from cattle grazing extensive pastures that are not amenable to traditional chamber-based measurements.

By gaining experience of research methods, farming practices and greenhouse gas issues in different systems, researchers will be opened up to a wider range of possible solutions and novel/ improved research methods. Improved understanding of the science and context for livestock greenhouse gas research - in particular the modelling of mitigation options in the UK and Brazilian contexts - will increase understanding of the need to set component research in a wider systems context. It will increase confidence in the applicability of mitigation options and models.
Exchange of knowledge and experience with equipment for measuring methane emissions under a range of management and environmental conditions will help advance techniques - in particular there is an urgent need for techniques for use with cattle grazing pasture within extensive production systems in both the UK and Brazil.