Barking up the right tree - forestry and sheep parasites

Intestinal worms are a costly problem for sheep farmers – affecting everything from growth and fertility to wool production and mortality rates. In the UK alone, these parasites cost the industry an estimated £42.3 million annually. To make matters worse, the worms are increasingly resistant to existing treatments, making new solutions a priority. 

William Clark, Forestry Transport and Innovation Advisor, talks about work underway to explore how forestry by-products, like bark, can solve this problem.

Through the innovation part of my role, I met Professor Spiridoula Athanasiadou from the Food Security Challenge Centre at Scotland’s Rural College (SRUC) in 2023.

Spiridoula is leading a fascinating BBSRC project that brings together an impressive range of partners:

• St Andrews University
• the University of Edinburgh
• Biomathematics and Statistics Scotland (BioSS)
• Scottish feed producers Norvite
• livestock co-operative Farm Stock
• the organic farming certification organisation Soil Association
• the Confederation of Forest Industries (Confor)
• Scottish Forestry

Their goal is to explore whether forestry by-products, specifically bark, could offer a new way to control parasites in sheep and other grazing livestock.

Scientists have long known that certain natural plant compounds can help animals fight off parasites. In the wild, animals will sometimes self-medicate by seeking out particular plants.

The challenge has been finding a cost-effective and sustainable way to harness these compounds at scale. 

This is where forestry comes in. Bark is a co-product of sawmilling and in 2023, Scottish sawmills sold more than 165,000 tonnes of bark for uses such as mulch, landscaping, and equine surfaces. 

The wonderful thing about this project is that it doesn’t disrupt the existing bark market at all. Quite the opposite. Spiridoula’s team is developing a clever way to extract the bark compounds. 

The extraction process uses water as a solvent. Rather than competing with current uses for bark, the team essentially ‘borrows’ it – washing the bark to extract the useful compounds, then returning it to the production line clean and ready for its next use. 

The potential benefits are significant: a higher-quality product; a potential new tool to tackle a £42 million problem; healthier sheep with fewer parasites; and a natural alternative to chemical treatments. 

Beyond the immediate application, the project also aims to develop a model, that will predict the potential antiparasitic activity of any bark extract, from different tree species, regions, and seasons. 

For me, this project is a brilliant example of what can happen when natural industries like forestry and farming work together.

Projects like this give me great confidence that by working with nature rather than against it, our industries can support the bright, green future we all hope for.

You can find out more about novel approach to parasitic disease, by reading the UK Research and Innovation paper on the subject. Contact details are also available for Professor Athanasiadou.

Forestry byproducts as novel therapeutics for parasite control in livestock