Ostertagia trifurcata (Nematoda: Trichostrongylidae) in cattle in Canada.
D000818:Animals; D002170:Canada; D002417:Cattle; D002418:Cattle Diseases; D008297:Male; D014251:Trichostrongyloidea / Q000302:isolation & purification*; D014252:Trichostrongyloidiasis / Q000662:veterinary