Exploiting plant diversity and phenology for livestock health under climate change

This project addresses the hypothesis that aligning plant phenology with seasonal parasite risks can enhance the effectiveness of tree-based solutions to disease threats, and hence their economic value.
Objectives:
1. Because plants use climatic cues to trigger seasonal events (=phenology), such events might predict risk periods for parasite infection. The spring scour worm emerges in response to rising soil temperature, and again in autumn when soil temperature falls to within a defined range. Annual data on dates of leaf burst, flowering and leaf fall for UK tree and woodland/hedgerow plant species will compared with records of scour worm outbreaks. Results will test the hypothesis that spring and autumn events in particular plants can predict disease risk in a given year and location, and support treatment decisions by farmers.

2. Tanniferous tree leaves attenuate parasite impacts. Used alone over sustained periods, however, their nutritional value is often low, and excessively high tannin concentrations reduce feed intake and digestion. Tannin concentration and chemical structure will be analysed for ash, apple and willow leaves, during growth and after leaf-fall or drying, with chemical composition, available protein-energy content, and in-vitro antiparasitic efficacy. Results will calibrate feed basket formulation for targeted tree fodder supplementation at key times of parasite risk. Selected mixes will be evaluated for digestibility and emissions in rumen simulators, and for palatability in feeding trials. Transmission models will evaluate consequences of targeted seasonal intervention for parasite epidemiology and selection of drug resistance.

3. We will measure parasites and their environmental correlates in field transects, and collect GPS data on sheep habitat use, to address the two-tailed hypothesis that trees modify parasite transmission potential.