Kikuyu poisoning and the army worm
Bryson, R.W.
Journal of the South African Veterinary Association 53(3): 161-165
1982
ISSN/ISBN: 1019-9128 PMID: 7175901 Document Number: 194068
In 1981, seven outbreaks of kikuyu poisoning in which 157 cattle died occurred in widely separated coastal areas of South Africa. Although the causal agent has not been identified, the predisposing factors are listed. They are, in order of importance: cattle grazing kikuyu grass (Pennisetum clandestinum), which has been damaged by army worm (Spodoptera exempta Lepidoptera), for ten or more days; small paddock not exceeding 1-2 ha, and normally heavily stocked; a period of drought followed by patchy rainfall, humid atmosphere and temperature between 10-14 deg C; paddocks often on latitude of approximately 02905S, sloping gently and protected on one side by a line of mature trees; cattle not kept under constant observation, as 'incubation' period can be up to 96 h. A review is given of existing knowledge of the disease including breed and species susceptibility, life cycle of the army worm, symptoms of the disease, pathology, treatment, experimental reproduction of the disease and possible causes. Existing knowledge of kikuyu poisoning is documented. The disorder affects cattle grazing on kikuyu grass (Pennisetum clandestinum), which has usually been damaged by army worm (Spodoptera exempta) at least 10 days previously. Mycotoxins may or may not be involved. There seemed to be no effective treatment. Advice is to use tracer animals on suspect pasture for at least 96 h before gradually introducing other animals. Sheep in New Zealand are reported to be unaffected, owing perhaps to their more selective grazing.