Aujeszky's disease virus (ADV) and swine influenza virus (SIV) are the causative agents of the main viral respiratory disease of growing/fattening pigs. Effective contro and prevention of both the above diseases is of majir importance for the affected farms, due to the caused severe economical losses. In this trial study, the effect of the vaccination of growing/fattening pigs against ADV and SIV with emphasis on growth parameters was investigated in a seropositive to both the above viruses farm. Five different tria groups, consisting of 60±3 11-week old growing pigs each, with vaccination schemes against ADV and/or SIV, oncluding an unvaccinated/control group were used for this purpose. Comparisons between trial groups were made with regard to growth parameters, as well as pathological and bacteriological findings at slaughterage. The results revealed that twice vaccinated animals against ADV and SIV performed significantly better in comparison to all other groups and no pathogens were isoated from their examined lung samples. On the contrary, Pasteurella multocida, non-haemolytic Staphylococcus spp and Proteus spp were isolated in a various frequency from the lung samples of al other groups.

Volume 47 (No. 3 p. 197-206) / 1996