2 December 2019
The impact that livestock has on our climate is a pressing issue for the farming and science communities as well as policy makers. Bringing these communities together, a one day conference held at SCI HQ London generated many talking points and exchanges of ideas.
Livestock has a major and growing role to play in human nutrition. It is an industry employing 1.3 billion people worldwide and 600 million of the world’s poorest households keep livestock as an income source. However Dr Sokratis Stergiadis, Associate Professor, School of Agriculture, Policy and Development, Reading University, UK, reminded delegates that livestock represented 15.5% of human-induced global greenhouse gas emissions, with dairy and beef being the main contributors to these emissions. With the global population expected to reach close to 10 billion by 2050 the demand for livestock products is set to increase.
It has already been found that optimising livestock production systems can reduce greenhouse gas emissions by 30%, but methods used need to ensure long-term efficacy, sustainability and resilience. Realising these three criteria within a policy framework for livestock is complex, with many factors coming in to play.
Nutrition is an essential element in the livestock policy. Methane gas production from livestock will clearly be impacted by their diet. Sharing some new strategies for feeding beef and dairy herds, Dr Jason Sands, Product Manager at Ocean Harvest Technology, explained how several bioactive compounds in seaweed, including proteins and fatty acids, are being found to be beneficial in animal nutrition and health. As well as nutritional benefits, Sands added that macro algae and their secondary metabolites have been shown to effectively decrease in vitro methane production. The red macro algae Asparagopsis taxiformis was found to have the greatest potential to inhibit methane production. However, Dr Sands added that for the successful adoption of seaweed as a strategy to reduce methane production in cattle, the seaweed must maintain, or enhance, rumen efficiency.
Considering the range of mitigation measures Dr Michael MacLeod, Researcher Sustainable ecosystems, land economy, environment and society at Scotland’s Rural College, stressed the need to look at the issue from both a supply and demand perspective. ‘On the supply-side, a review in 2015 identified 182 mitigation measures, but how can these be translated into coherent policy? ’ Dr Macleod commented. Looking at the demand side, issues such as changing consumption habits would have a significant impact mitigating emissions.
Of course measuring the efficacy of mitigation methods is essential and Professor Tom Misselbrook, Senior Research Scientist in the Sustainable Agricultural Sciences department at Rothamsted Research shared the development of robust models that now allowed greater certainty around the reporting of greenhouse gas emissions from livestock. Professor Misselbrook explained that more precise inventory methods for measuring emissions from livestock at various stages of their life cycle, accounting for their location in the UK and type of feed, amongst other parameters, meant that the UK could better minimise emission uncertainties leading to improved lifecycle analysis.
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