title: Pathophysiologic effects of Ostertagia ostertagi in calves and their prevention by strategic anthelmintic treatments.
abstract: Pathophysiologic effects of Ostertagia ostertagi infection and their prevention by strategic anthelmintic treatments were studied in 3 groups each of 6 steer calves. Group-1 calves were noninfected controls. Group-2 calves were inoculated with 100,000 third-stage larvae on the 1st and 28th days of the experiment and grazed on pasture initially free of contamination. Group-3 calves were on a similar regimen as those in group 2, but were also treated with ivermectin 9 days after each larval inoculation. Group-2 calves had increased plasma pepsinogen and gastrin values and decreased weight gains, and total serum protein and albumin concentrations from the 2nd week of infection onward. They were anemic at 10 to 12 weeks and had lower carcass and meat quality at slaughter. Strategic anthelmintic treatments were effective in preventing these effects and calves in groups 1 and 3 had similar performances. On the basis of our findings, high pepsinogen values were related to worm burdens, whereas high gastrin concentrations were related to gastric lesions.
authors.affiliation: Department of Animal, Veterinary and Aquatic Sciences, University of Maine, Orono 04469.
authors.forename: L
authors.initials: L
authors.lastname: Xiao
authors.forename: H C
authors.initials: HC
authors.lastname: Gibbs
authors.forename: C
authors.initials: C
authors.lastname: Yang
mesh_terms: D000018:Abomasum / Q000473:pathology; D000818:Animals; D001798:Blood Proteins / Q000032:analysis; D001806:Blood Urea Nitrogen; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy / Q000503:physiopathology*; D005243:Feces / Q000469:parasitology; D005755:Gastrins / Q000097:blood; D006400:Hematocrit / Q000662:veterinary; D007559:Ivermectin / Q000627:therapeutic use*; D008297:Male; D008460:Meat / Q000592:standards; D009752:Nutritional Status; D010028:Ostertagia / Q000302:isolation & purification; D010029:Ostertagiasis / Q000188:drug therapy / Q000503:physiopathology / Q000662:veterinary*; D010270:Parasite Egg Count / Q000662:veterinary; D010435:Pepsinogens / Q000097:blood; D011897:Random Allocation; D012710:Serum Albumin, Bovine / Q000032:analysis; D015430:Weight Gain
chemical_list: D001798:Blood Proteins; D005755:Gastrins; D010435:Pepsinogens; D012710:Serum Albumin, Bovine; D007559:Ivermectin