Abstract

Management of nematode parasites of grazing livestock is essential, but there is concern about the potential environmental risk from agents used in their control. In this experiment, parasites in young cattle were controlled, using ivermectin boluses or the predacious fungus Duddingtonia flagrans, over 3 years. Treatment differences were sought among the soil nematodes recovered from soil samples collected from the paddocks on which treated animals grazed, and compared with similar samples taken from an untreated control paddock. Analysis of the soil nematode fauna on 21 occasions failed to demonstrate any impact of parasite management on soil nematodes. In 0-22 mm soil total nematode abundance averaged 524 000 m(-2), with 18 nominal taxa and. H' diversity 2.41. There were both underlying paddock and year-to-year, climate-related, differences. The results of this trial not only confirm the lack of any adverse environmental impact of D. flagrans, a promising biological control agent, on soil nematodes, but also fail to show any impact arising from the use of ivermectin boluses.

Keywords

bacterial feeding; diversity; Duddingtonia flagrans; environmental impact; Helicotylenchus; ivermectin; nutrient cycling; pasture; Tylenchorhynchus

Published in

Acta Agriculturae Scandinavica, Section A - Animal Science
2002, volume: 52, number: 4, pages: 233-242
Publisher: TAYLOR & FRANCIS AS

Authors' information