Biological control of field infections of nematode parasites of young sheep with Duddingtonia flagrans and effects of spore intake on efficacy

A field study was undertaken to determine the effects of feeding Duddington ia flagrans to young Merino sheep on pasture. A total of 60 mixed sex lambs 4-5 months old were divided into six even groups on the basis of liveweigh t. On Monday to Friday, each week for 6 months, three groups were offered b arley grains on which D. flagrans had been cultured while the other three g roups remained untreated. Every 4 weeks liveweights were recorded and faeca l samples collected for nematode egg count estimation. Feeding D. flagrans reduced faecal egg counts and tended to improve liveweight gains, but consi derable differences were observed between groups within treatment. These di fferences are thought to result from variations between the groups in consu mption of the treated barley with the "best" consumers showing the greater effects of treatment. (C) 2001 Elsevier Science B.V. All rights reserved.