title: Serologic prevalence of ovine progressive pneumonia in a western range flock of sheep.
abstract: Of 254 sheep examined for antibodies to the virus of ovine progressive pneumonia, 162 (63.8%) were seropositive. The mean age of the seropositive ewes was 4.9 +/- 1.8 years, which was significantly greater than that for the seronegative ewes (4.1 +/- 2.3 years). The age-specific prevalence increased with ewe age, from 25% among yearling ewes to 85% among 7-year-old ewes. Seropositive ewes produced more pounds of live lamb at birth than did seronegative ewes.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis; D005260:Female; D011021:Pneumonia, Progressive Interstitial, of Sheep / Q000453:epidemiology* / Q000276:immunology / Q000635:transmission; D011247:Pregnancy; D012756:Sheep; D014481:United States
chemical_list: D000907:Antibodies, Bacterial