Roslin Institute contributions towards mitigating the impact of livestock on climate change

We welcome the UK Government’s commitment to Net Zero as part of a global strategy to reduce greenhouse gas emissions and rising global temperatures.

The climate crisis is one of the greatest problems humanity has ever faced, and we welcome the UK Government’s commitment to Net Zero as part of a global strategy to reduce greenhouse gas (GHG) emissions and rising global temperatures.

Animal farming – essential for global food and nutrition security – is estimated to contribute around 5.8 per cent of global GHG emissions. While significantly lower than the energy and transport sectors, it is important that every sector responds to the challenge of reducing their contribution to climate change, and the Roslin Institute is committed to enabling sustainable animal production and improved animal health and welfare while reducing the carbon footprint of animal farming towards Net Zero, both in the UK and internationally.

Two recent reports commissioned by the UK Government, the National Food Strategy, and a report from the Climate Change Committee (CCC), have called for a reduction in the consumption of meat and dairy products of 30-35 per cent as a contribution to achieving Net Zero and improved human health.

However, global trends in meat and dairy consumption show large year-on-year increases, driven by growth in Asia and low- and middle-income countries (LMICs). Indeed, in LMICs, animal farming is a key route from poverty and malnutrition, and animal source food products provide essential nutrients that are absent from other food sources, and which are essential for healthy growth and development.

Even in the UK and the European Union (EU), meat and dairy consumption are at their highest level to date. Reversing this trend and implementing a 30-35 per cent reduction is therefore a significant challenge, and we must plan to reduce the environmental impact of livestock independently of changes in consumer behaviour.

The Roslin Institute focuses on strategic research and knowledge translation to develop a range of scientific, technical, and systematic solutions that will help achieve the United Nations Sustainable Development Goals including Zero Hunger, while also helping drive farmed animal production towards Net Zero.

These include improving production efficiency and welfare via innovation in selective breeding, reducing disease losses through development of vaccines, therapeutics and disease-resistant animals, development of novel feed additives and alternative feed sources – such as insects – probiotic and microbiome products.

Genome engineering has the potential to transform food production, both by validating the role of genetic variation associated with traits that can be selected via conventional means and by modification of animal genomes to instil beneficial traits such as resistance to pathogens or removing deleterious variation.

These solutions, which are complementary to changes in the supply chain and shifts in consumer diets, will be key to achieving Net Zero in the animal farming sector. Moreover, it is important to recognise that not all meat has the same carbon footprint, with poultry and aquatic species being far more efficient in converting energy from feed to meat. Indeed, certain lower-trophic aquaculture species such as bivalves have been shown to be important for carbon sequestration.

Many of these solutions have also been highlighted by the All-Party Parliamentary Group on Science & Technology in Agriculture, who said that ‘advanced breeding technologies such as genomic selection and gene editing – in which British Science is a world leader – offer a more forward-looking approach to reducing GHG emissions’; and the Farming for 1.5° group who highlighted ‘better animal health, improved genetics and early adoption of feed additives’ as future solutions likely to have high impact.

Here at the Roslin Institute we have internationally leading research programmes targeting all the above areas, and our research aims to help the farmed animal food system achieve Net Zero without compromising global and national food and economic security, animal welfare or the eco-system.

Breeding and genetics

Animal breeding focuses on the use of quantitative genetics to evaluate the genetic merit of individual animals and using those evaluations to select for animals and offspring with improved characteristics.

A key target of selective breeding is improvement in efficiency: achieving higher production levels whilst using fewer resources, which reduces the climate impact of the improved animals. The CCC has called for a reduction in the number of farmed animals in the UK, whilst recognising that much progress has already been made.

A good example of this is the UK dairy herd, which has reduced in size by 27 per cent since 1996 whilst maintaining the same milk production: 15-16 million litres of milk per year. This has been achieved through improved genetics and management. Using fewer animals to meet demand can also free up land that can be used for rewilding and carbon capture, and in some cases crops where humans and animals compete for resources.

At the Roslin Institute we partner with animal breeding companies to develop, evaluate, and implement advanced technologies in their breeding programmes. For example, by working with livestock breeding companies, we can reduce the amount of resources each animal needs to produce the same amount of meat or milk, which means we can produce more food with fewer animals or fewer resources.

Since some of the major resources that animals need are crops that are grown for animal feed, by breeding for more efficient animals, we can free up land that would otherwise be used to grow these crops, and this land can then be used for carbon capture or rewilding.

Techniques developed at the Roslin Institute have been estimated to have saved over 600,000 tonnes of animal feed, simply through improvements in feed efficiency. This represents a direct reduction in the climate impact of livestock, and the resources freed up by those advances can be used in further climate mitigation. Other examples include Roslin’s contributions to breeding animals with improved disease resistance or resilience to mitigate the spread and impact of infectious diseases as outlined below.

Realising genetic gains is aided by the structure of breeding populations. For example, the genetic make-up of the vast majority of the 75 billion chickens estimated by the Food & Agriculture Organization to be reared for meat globally each year is managed by a small number of companies.

Optimising the attributes of their breeding stock allows all animals derived from that stock to benefit from heritable changes. The same applies in aquaculture, which now accounts for over half the global supply of fish. Therefore, changes made to the breeding stock of a few companies can have enormous impact in terms of environmental sustainability and efficiency. We are also determined that any such gains do not come at the expense of welfare, and indeed much of our research focuses specifically on improving health and welfare traits.

Infectious diseases

Infectious diseases are a huge threat to Net Zero agriculture, as they are directly associated with high rates of mortality of farmed animals and with an increase in resources utilised to maintain a high health status. This includes the use of antibiotics, which in turn exerts pressure for transmissible drug resistance that can later affect the treatment of human diseases.

Much of Roslin’s research focuses on the development, evaluation, and implementation of innovative solutions to infectious disease control. These range from genetic tools to breed animals that are genetically more resistant or resilient to infections, development and evaluation of safe and effective veterinary vaccines, improved diagnostics, and data-driven epidemiological tools to predict disease spread and aid decision-making.

Examples include our identification of a marker for resistance of salmon to infectious pancreatic necrosis, which since being selected in breeding schemes is estimated to have averted the deaths of up to 18 million salmon, saving farmers and producers up to £234m between 2013 and 2020. As the carbon footprint of salmon is estimated to be 11.9kg CO2 per kg of consumed food, this impact equates to hundreds of millions of kilograms of CO2 saved.

We have also demonstrated the potential of genome editing in control of devastating animal diseases. For example, we found that precise removal of part of a gene in pigs confers complete resistance to the virus that causes porcine reproductive and respiratory syndrome (PRRS) in pigs, without harming the animals. PRRS exerts substantial welfare and economic costs globally. We are now working with industry partners to obtain regulatory approval for such animals to be used in food production and work with the public and not-for-profit organisations to explain the technology.

Removing the loss of millions of pigs from the global supply chain by mitigating PRRS will have a huge climate impact, removing unnecessary GHG emissions associated with pigs that die before entering the food chain. Similar advances are in the pipeline for avian influenza and other diseases.

Microbiomes and methane emissions

Methane is a potent greenhouse gas, and ruminants such as cattle and sheep are one of the biggest sources of methane related to human activities. Methane arises from fermentation in the stomach of ruminants linked to specific groups of microbes.

In collaboration with our partners in Scotland’s Rural College, we have demonstrated that high methane producing cattle have a higher abundance of enzymes involved in the methane production pathway, and our award-winning research has shown that the microbiome can explain substantial amounts of the variation in methane production between individuals and that much of this is under host genetic control.

We have published a set of rumen microbiome biomarkers that can be used to predict methane emissions, and we have produced the most detailed genomic maps of the rumen microbiome to date to accelerate research in this area, including the genome sequences of thousands of previously undiscovered methanogenic microbes. Together with industry partners, we are working towards integration of rumen microbiome data into breeding programmes to produce lower methane-producing cattle.

Aquaculture

Aquaculture is becoming the primary source of seafood for human diets and has a key role in providing animal protein for human food and nutrition security, particularly in low- and middle-income countries.

It is the fastest growing food production sector and contributes less than 0.5 per cent of the total anthropogenic greenhouse gas emissions. As recently domesticated species, there is enormous potential for sustainable genetic improvement, and Roslin research is internationally leading in the development and application of genomic technologies to help achieve this.

This includes new cost-effective applications of genetic markers to improve disease resistance, in particular for many aquaculture diseases where few other control opportunities exist. This ranges from control of IPNV in salmon, see above, through new genomic tools for farmed Nile tilapia and innovation in formative genetic technologies for lower-trophic species such as oysters

Alternative feed sources

A major source of climate impact associated with livestock production is the use of soya in animal feed. It has been estimated that over three-quarters of the soya plants grown globally are fed to livestock, although livestock mostly eat soya meal, which is the waste product of soya bean and soya oil production, both of which are for human consumption.

Growing crops such as soya uses high quality land that could otherwise be used for rewilding or carbon capture, and some believe that clearing land for soya growth is a cause of rainforest clearance.

Soya meal is fed to livestock as it is high in protein. The UK imports millions of tonnes annually, a third of which is fed to animals, predominantly pigs, poultry, and fish.

Here at Roslin, we are working with our industry partners to develop alternatives to soya which are also protein-rich and can be fed to farmed animals, including black soldier flies. The larvae of this species are very efficient at converting organic matter, including food waste and by-products from the food industry, into protein. In addition, they are easy to handle in large facilities, and can be easily processed to be fed to fish, pigs, chickens, and other animals.

This could not only reduce our reliance on imported soya meal, but make more effective use of food waste, much of which currently decomposes and contributes to GHG emission. We are applying our world-leading expertise in genetics and breeding to the black soldier fly and believe this could replace soya in the animal food chain, and thus have a major impact on climate change.

Global Solutions

Much of the predicted growth in farm animal consumption will come from low- and middle-income countries, including many in Africa. Particularly in LMICs, livestock have been described as essential for nutritional and economic security. The Centre for Tropical Livestock Genetics and Health (CTLGH) was established to improve the productivity, health, and sustainability of livestock in sub-Saharan Africa using the latest genetic and genomics technologies and related innovations.

The Centre focuses on improving the efficiency of both dairy and poultry production systems, as well as using genetics, genomics, and animal breeding to produce animals that are tolerant to diseases and better adapted to their environment.

By removing losses due to disease and by improving the efficiency of livestock food production in LMICs, CTLGH will have a significant impact on improving the sustainability of livestock in LMICs, and thus reducing their carbon footprint.

A recent example includes the identification of a region of the genome that renders cattle tolerant of the parasitic disease East coast fever, which kills over a million cattle a year in sub-Saharan Africa.

Similarly, we identified a key marker of resistance of tilapia, a key aquaculture species in LMICs, to a deadly disease caused by tilapia lake virus. Working with breeders, we aim to implement these gains in breeding schemes to save lives, preserve resources and reduce carbon emissions.

Leading the conversation

In October 2018, Roslin organised and hosted a workshop on precision breeding, which brought together scientists from several different institutes, centres, and universities, with a focus on food production.

The recommendations were wide-ranging, but included the introduction of long-term, goal-oriented research programmes capable of tackling global food security and the impact of the food system on climate change; and greater integration of plant and animal breeding communities to share technologies and expertise, and work on shared goals – for example, producing crops specifically bred for livestock consumption, and reducing the climate impact of both.

A further workshop on ‘The future Role of Farmed Animals in Food Production’ in November 2019 brought together scientists, industry representatives and policy makers to critically review the threats and challenges from and for livestock production in the context of Net Zero food production.

The workshop produced a consolidated document sent to the Biotechnology and Biological Sciences Research Council (BBSRC) that outlined the key evidence and knowledge gaps needed for robust policy making to shape the future of livestock production as well as the associated data and research priorities.

Researchers at the Roslin Institute are also founding members of major international projects to understand how farmed animal genomes are organised, expressed, and regulated. In turn this provides critical resources to understand the genetic basis of traits relevant to the development and lifelong health of animals.

This international consortium is very much focused on improving the efficiency and sustainability of livestock, and recently Roslin researchers led a team who published a roadmap for how functional genomics data can be used in livestock breeding programmes designed to improve efficiency and sustainability traits.