Moving towards net-zero through improving animal health

Livestock systems contribute up to 20% of the world’s greenhouse gas emissions (GHGs), making improvements in livestock efficiency essential to achieve net-zero targets. Approximately one-fifth of global animal protein is lost due to disease, partly through reduced growth, lower fertility, and disease induced mortality. Ubiquitous parasites also have direct impacts on GHG emissions. Enhancing animal health presents significant opportunities for reducing emissions, however the GHG mitigation potential of disease control has yet to be quantified.

We aim to review literature on emissions and disease for ruminant and monogastric systems and identify existing data sources for health and emissions. By looking across sectors for the first time, we will reveal commonalities across livestock-systems, and identify barriers to developing a standardised cross-sector approach to quantifying impacts of animal health on emissions. By communicating the importance of animal health in achieving net-zero to industry stakeholders, our efforts will empower behavioural change towards more sustainable and resilient livestock systems.

Project lead: Naomi Fox, SRUC

Project members: Nicola Noble, National Sheep Association; Samantha Green, Applied Group Poultry; Anna Macready, University of Reading

Findings

• Improving animal health is a powerful yet under-recognised strategy for reducing livestock greenhouse-gas emissions.
• There is a strong focus on improving productivity, however breeding for high growth and feed efficiency can increase susceptibility to disease, highlighting the need for a more holistic approach that also prioritises animal resistance and resilience.
• There is no standardised methodology for quantifying impacts of disease on emissions. By creating a robust framework for developing clear, quantifiable information on the link between animal health and emissions, we can empower farmers and industry stakeholders to make informed decisions that contribute to national climate goals.
• Monogastrics are a blind spot in our understanding of interactions between health and emissions. Pigs and poultry emissions are primarily driven by levels of feed, lighting, heating, ventilation and transport. Disease alters productivity, however the impacts of disease on emissions per unit of product are not well understood.

Suggestions for further research

• A standardised methodology is needed for quantifying impacts of livestock disease on emissions. This should initially focus on ruminants, as the primary methane-emitters, then be expanded to other systems.
• Predicting impacts of monogastric disease on emissions is not constrained by the difficulties faced in studying ruminant systems, as it is not reliant on understanding direct interactions between infection and enteric fermentation levels. Mongastric emissions are driven by energy in (e.g. for feed, transport, heating, cooling, ventilation) versus product out. Disease will affect the efficiency of these livestock systems in quantifiable ways, yet impacts of health on emissions have only been explored for a very limited number of monogastric pathogens.
• The short-term impacts of monogastric disease outbreaks (e.g. highly pathogenic avian and swine influenza) on market dynamics and consumer behaviour remain under-studied, particularly with respect to potential temporary shifts towards ruminant protein consumption and the resulting implications for increased GHG emissions.