Validation of the commercial viability and operational feasibility of bark-derived compounds as a sustainable parasite control solution

Parasitic infections are a significant and growing threat to livestock health and farm profitability. In the UK alone, such infections cost the sheep industry an estimated £84 million annually due to lost productivity and increased mortality. Across 18 European countries, helminth infections cost the livestock sector over £1.54 billion each year. Antiparasitic drugs have traditionally been used to control livestock infections, but drug resistance—part of the broader antimicrobial resistance (AMR) phenomenon—is now widespread. Losses attributed to resistance accounting for £32.5 million in Europe - including £3.5 million in the UK sheep sector. Recent reports indicate that the prevalence of resistance in the UK varies between 20-100% depending on the class of drugs. The impact of drug resistance is cascading across multiple domains. Economically, resistance reduces productivity, slows growth rates, and limits yield. Environmentally, longer finishing times increase methane emissions due to prolonged ruminant fermentation. From a public health perspective, AMR is an escalating concern, particularly given the overlap between veterinary and human drugs. There are also serious implications for animal welfare, as persistent infections lead to avoidable suffering. Efforts to reduce reliance on antiparasitic drugs have included several alternative strategies. Targeted anthelmintic treatment, involves dosing only a subset of animals but still depends on effective drugs being available. Grazing management strategies, such as pasture rotation, can help reduce reinfection rates but require significant land and planning resources. Biological control using fungi that disrupt the parasite life cycle offer some promise, but their effectiveness is often highly dependent on specific climatic conditions. In practice, many of these alternatives are either impractical, or simply unavailable to most UK farmers—highlighting the need for complementary, scalable solutions that can work within existing farming systems. Our proposed solution builds on a growing body of evidence that certain plant compounds, particularly those found in tree bark, can effectively disrupt the parasite life cycle. Bark from several coniferous species contains condensed tannins and other polyphenols, which may act through different mechanisms than conventional drugs. Studies performed by the PI have demonstrated that bark-supplemented diets can reduce parasite burden by 50% without a negative impact on performance, suggest a promising role for bark-derived compounds as a natural, feed-based intervention that could be incorporated into routine livestock management. This approach also takes advantage of an underutilised UK resource. Approximately 40% of felled timber in the UK results in sawmill by-products, including large volumes of bark. Much of this material is currently used for low-value purposes such as energy generation or horticulture. By extracting antiparasitic compounds from this bark and incorporating them into feed additives, we can create a high-value application that adds economic and environmental value across both the forestry and agricultural sectors. This circular use of local by-products supports more sustainable and resilient food systems while helping farmers manage parasite risk more effectively.