| prevalence of antibodies to haemophilus pleuropneumoniae in iowa swine. | the prevalence of complement-fixing (cf) antibodies to haemophilus pleuropneumoniae in iowa swine was determined by testing samples collected randomly from each of 9 crop-reporting areas (9 to 12 counties) in iowa in approximate proportion to the number of swine marketed annually from each area. for testing, a pooled antigen composed of serotypes 1 to 5 of h pleuropneumoniae was used in a modified direct microtiter complement-fixation test. of 7,348 sera tested, 2,362 or 32.1% had cf antibodies ... | 1982 | 7149390 |