Biological control of gastrointestinal nematodes of sheep in Rajasthan state (India): Screening of nematophagous fungi locally isolated from fresh faeces of sheep

Abstract

Isolates of predacious fungi (Arthrobotrys oligospora and Duddingtonia flagrans) obtained locally from fresh faecal samples of sheep from farm and field flocks in 2 important zones (semi arid and arid) of Rajasthan were screened for their in vitro predatory activity and ability to survive passage through the gastrointestinal tract of sheep. Two and three isolates of A. oligospora obtained from organized farm and field flocks, respectively, of each zone and only isolate of D. flagrans from organized farm of semi arid zone were screened. All the isolates screened possessed excellent predatory activity on faecal culture assay. D. flagrans isolate was much more efficient than the isolates of A. oligospora. Of 10 A. oligospora isolates tested, 3 isolates (from arid zone) showed excellent survival whereas, 5 isolates (4 from semi arid and 1 from arid zone) had very poor survival and 2 isolates (one from each zone) did not survive at all at the conidial concentration used.