Vaccination against swine enzootic pneumonia in field conditions: effect on clinical, pathological, zootechnical and economic parameters

A field study was carried out to evaluate the effect of vaccination against swine enzootic pneumonia in different production systems (closed or one-si te, and open, two- or three-site, systems). The percentage of mortality sho wed statistically significant differences (p < 0.001) in favour of vaccinat ion in all the production systems examined. Zootechnical and economic param eters also reflected the benefits of vaccination, although only the feed co nversion ratio showed statistically significant differences (p < 0.030). A macroscopic study of lungs at slaughter pointed to statistically significan t differences (p < 0.001) in favour of vaccination in the one- and two-site production systems. The histopathological and immunocytochemical study sho wed complete concordance with the macroscopic diagnosis (p < 0.001). Such r elationship confirms the suitability of macroscopic diagnosis in field cond itions.