DNA insights could help feed the world sustainably

The United Nations’ Food and Agriculture Organization estimates that, by 2050, the world’s population will be almost 10 billion, and that consumption of animal products will rise considerably.

Meeting this demand for food in a sustainable way that helps mitigate climate change and meets societal expectations, poses the challenge of producing more food from farmed animals using fewer natural resources.

Scientists around the world are working towards improving efficiency of food production by looking at the complete genetic code of farmed animals – their genome – to better understand how it drives useful characteristics, such as resistance to disease, resilience to extreme climates and more efficient utilisation of feed.

This knowledge could be used by farmers and breeders to improve animals’ health, welfare and productivity, while conserving biodiversity, protecting the environment and adapting to a changing climate.

Improving selection

A single trait in an animal can be controlled by multiple parts of the genome. The optimum approach to breeding in those cases is genomic selection, which involves using maps of the genome, highlighting parts of the DNA linked to traits of interest.

Having better quality maps of the genomes of farmed animals can improve the accuracy of genomic selection for traits of interest.

Disease resistance

There is major potential in improving resistance to disease by selective breeding, and genomic tools can make the process more efficient and accurate.

For instance, genomic selection can potentially speed up genetic gain for disease resistance by an average of 25 per cent in aquaculture species compared with using pedigree information, studies have shown.

One of the major health and welfare problems facing farmed salmon is sea lice. These parasites attach to the skin of the fish, often causing open injuries and stress. Different species show varying resistance to sea lice – while Atlantic salmon is susceptible, coho salmon is almost completely resistant. Learning about the genomes and their function allows scientists to perform meaningful cross-species comparisons in their response to lice.

Dr Diego Robledo, an aquaculture expert at the Roslin Institute, said: “This knowledge could help us identify the key mechanisms underlying resistance of coho salmon to lice, which we can then use to increase resistance in Atlantic salmon via different methods, including genome editing. This area is a major focus for us at Roslin and our collaborators in the next few years.”  

Tackling outbreaks

Information derived from the genomes of farmed animals enables research into preventing and mitigating diseases.

Having high quality information about the genomes of animals has huge potential to prevent and mitigate the effect of disease outbreaks quickly, limiting potential effects on food production and improving animal welfare.

Dr Emily Clark

At the Roslin Institute, research has shown the value of having knowledge of an animal’s genome. For instance, in 2017, work led by Dr Christine Tait-Burkard used precise genome-editing techniques to remove a small section of a gene that is targeted by a deadly pig virus, called porcine reproductive and respiratory syndrome virus. This conferred resistance to a disease that kills new-born piglets and costs the pig production industry more than £1.75 billion per year in the US and Europe alone.

Conserving biodiversity

Animals have several characteristics that help them thrive in different environments. For instance, some animals might be particularly suited to living in the very dry, long, hot summers and very cold winters that are common in the region where they live. However, breeders may risk losing these important traits when improving one specific trait, such as disease resistance. This is why conserving the biodiversity in locally adapted populations of animals is important.

For example, Roslin scientists recently analysed genomes and climatic data which suggested that precipitation has greater influence than altitude and temperature on adaptation of sheep to diverse local ecosystems in Ethiopia.

Dr Emily Clark said: “One of our priorities is to understand genomic variation between local animals and commercial ones, and how that links to different physical traits, so that we know what parts of the genome need to be conserved.”

Similar approaches are used in fish breeding programmes that focus on genetic improvement of several traits simultaneously, including growth, fillet characteristics, and disease resistance.

Reducing environmental impact

Pressures on the world’s limited natural resources and climate change threaten the sustainability of food production. Understanding the genome of farmed animals may help make food production more sustainable in the long term, via several routes.

Dr Emily Clark added: “By understanding how the parts of the genome that translate into traits of interest are controlled in farmed animals, we can turn genomic variation into sustainable genetic gain. This knowledge will contribute to production of healthy food using fewer natural resources whilst conserving biodiversity. This will help to mitigate some of the challenges faced by food production in the coming decades and contribute to meeting the objectives of the European Green Deal to boost efficient use of resources and restore biodiversity.”  

Breeding livestock and fish based on genomic information will improve resistance to disease, which will reduce the need for antibiotics and other chemicals against parasites. This reduction of chemicals in the environment and of the amount of animals produced will subsequently decrease the environmental impact of food production.

Advances in selective breeding methods, augmented by ever-improving genomic maps of aquaculture species, have much potential to improve the efficiency of aquaculture production. Genetic improvement results in stocks that are more resistant to problematic infectious diseases, and also require less feed to grow to market size. This can improve animal welfare while also improving production efficiency and reducing their carbon footprint.

Professor Ross Houston

International collaboration

Scientists around the globe are working together as part of the Functional Annotation of ANimal Genomes (FAANG) consortium to fully characterise and define the genomes of farmed animals. Initial stages of the initiative focused on a small number of animals. Research priorities for the coming decade will unlock the genomic diversity in whole populations of farmed animals.

The new set of research priorities outlined for the consortium will contribute to improving the efficiency of food production and mitigate the effects of climate change.

Though the research costs of the FAANG proposals are significant, they are dwarfed by the societal and economic benefits that will follow. The Roslin Institute, along with our partners around the world, co-ordinate and co-operate to ensure the benefits of genomics are delivered to animal breeders, farmers and ultimately the general public. This international co-operation is key and we are pleased that funders see the benefit in our work. We hope it continues as we help to deliver the food system the world needs.

Professor Mick Watson

Related links

‘From FAANG to fork’ research priorities

Gene map to aid studies of key traits in sheep

Gene-editing tool to speed disease studies in fish

FAANG