Effects of feeding lupin seed naturally infected with Phomopsis leptostromiformis to sheep and pigs.

Lupin seed, 10% of which was naturally infected with Phomopsis leptostromiformis was obtained from 2 different sources and stored either conventionally, or in a warm and humid environment, for 45 weeks. Only very low levels of toxicity were apparent during the storage period and in the warm, humid environment the level of infection of P. leptostromiformis was gradually reduced and eventually eliminated. The 2 batches of infected seed, and non-infected lupin seed, were fed to sheep as sole rations for 40 weeks, or as part of feedlot rations for 10 weeks, and to baconer pigs as part of grower and finisher rations for 16 weeks. In the 40-week feeding trial mild lupinosis developed in sheep fed from one batch of infected seed, but there was no evidence of lupinosis in sheep fed the feedlot rations, or pigs fed the grower and finisher rations. It is suggested that lupin seed with levels of Phomopsis-infection of up to 10% could be safely fed to sheep and pigs under commercial conditions.