Biological control of trichostrongylid infections in calves on pasture in Lithuania using Duddingtonia flagrans, a nematode-trapping fungus.
The effect on the pasture contamination level with infective trichostrongylid larvae by feeding the nematode-trapping fungus, Duddingtonia flagrans at two dose levels to first time grazing calves was examined in Lithuania. Thirty heifer-calves, aged 3-6 months, were divided into three comparable groups, A, B and C. Each group was turned out on a 1.07 ha paddock (a, b and c). The paddocks were naturally contaminated with infective trichostrongylid larvae from infected cattle grazing the previous year. Fungal material was fed to the animals daily during a two month period starting 3 weeks after turnout. Groups A and B were given 10(6) and 2.5x10(5) chlamydospores per kg of live weight per day, respectively, while group C served as a non-dosed control group. Every two weeks the heifers were weighed and clinically inspected. On the same dates, faeces, blood and grass samples were collected. From mid-July onwards, the number of infective larvae in grass samples increased markedly (P<0.05)on paddock c, whereas low numbers of infective larvae were observed on paddocks a and b grazed by the fungus treated groups. However, the results indicate that administering fungal spores at a dose of 2.5x10(6)chlamydospores per kg live weight per day did not significantly prevent parasitism in calves, presumably due to insufficient suppression of developing infective larvae in the faeces. In contrast, a dose of 10(6) chlamydospores per kg lowered the parasite larval population on the pasture, reduced pepsinogen levels (P<0.05), and prevented calves from developing parasitosis.
Sarkūnas
M
M
Lithuanian Veterinary Academy, Department of Infectious Diseases, Tilzes 18, 3022 Kaunas, Lithuania. minsar@lva.lt
Larsen
M
M
Nansen
P
P
Hansen
J W
JW
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology / Q000628:therapy*; D005243:Feces / Q000469:parasitology; D005658:Fungi; D010270:Parasite Egg Count; D020116:Pepsinogen A / Q000097:blood; D010572:Pest Control, Biological / Q000379:methods*; D006109:Poaceae / Q000469:parasitology; D014253:Trichostrongylosis / Q000469:parasitology / Q000628:therapy* / Q000662:veterinary*; D014254:Trichostrongylus / Q000302:isolation & purification; D015430:Weight Gain
D020116:Pepsinogen A