A locally adapted variety of the pasture crop, Sulla, (Hedysarum coronarium) could naturally control parasitic worms in grazing sheep and cattle.

Worm burdens have fallen by as much as half in overseas animal studies with Sulla.

The plant’s condensed tannins, which act as a natural chemical defence against bacterial and insect predation, also produce an anti worming or ‘anthelmintic’ effect.

The Department of Agriculture’s Kevin Foster and Peter Skinner have worked through the University of Western Australia (WA) based Centre for Legumes in Mediterranean Agriculture (CLIMA) for two years to adapt a Sulla forage cultivar for WA’s medium to heavier soils.

According to Mr Foster, Sulla is palatable, high in protein, ‘non-bloating’ and could be used by organic farmers as an alternative to chemical drenches. Its use in conventional farming systems could reduce the chance of worms developing resistance to drenches.

“The condensed tannins also protect dietary proteins against rumen degradation to enhance feed value. Lamb liveweight gains of 257 grams per day have been reported in New Zealand, which is comparable to that achieved in feedlots,” he reported.

Sulla’s deep roots allow for extended spring growth, while its erect structure makes it suitable for fodder and means seed can be harvested with conventional cereal headers.

“The pasture’s biennial character allows for rapid regeneration and water use during autumn and early winter, when feed is often scarce,” Mr Foster explained.

Current varieties require post harvest dehulling, which adds to seed costs, but ongoing research will target the development of varieties with soft pods for direct sowing.

Supported by both the Rural Industries and Grains Research and Development Corporations, CLIMA has also targeted increased herbage yields, leaf to stem ratios and seed production. CLIMA will continue to refine selections during 2004, ahead of a commercial variety release in 2005.