Grazing and Feeding
Grazing Stubbles
Lupin seed losses during harvesting can exceed 150kg/ha, making lupin stubble residues a very nutritious livestock fodder for grazing in-situ.
Sheep and beef cattle tend to do better on lupin stubble than on cereal stubble because of the high energy value and protein content of the remaining seed. The low starch content of lupin seed also virtually eliminates the risk of digestive upsets (lactic acidosis) common when they are introduced to cereal stubbles.
Care should be taken not to overgraze stubbles to the extent that the soil surface is exposed to erosion risk.
Lupinosis
Lupinosis is caused by toxins produced by the fungus Diaporthe toxica which grows on lupin stubbles. As a clinical entity, lupinosis was first recognised in 1872 in Germany when numerous sheep deaths were associated with ingestion of the plant. Since then, lupinosis has been reported in the USA, Poland, New Zealand, Australia, the Republic of South Africa and Spain. However, it is in Australia where the lupin stubbles have been extensively used a fodder, that lupinosis has assumed major importance. Varieties resistant to the fungus greatly reduce the risk of stock losses.
Any animals grazing lupin stubble may be affected by lupinosis, but sheep are the most severely affected because they are most sensitive to the toxins. Toxin production by the fungus is favoured by warm, moist conditions such as those following summer rain.
