EN
The purpose of the survey was to assess the prevalence of BHV-1, PI-3, BHV-4, BRSV and BVD in the bovine respiratory tract. Sera were taken from cattle of four districts located in the south-western part of Poland: 349 sera were collected from cows, 183 from heifers and 27 from bulls with no clinical signs of the disease. The findings revealed higher indices of infection caused by the viruses in the group of cows as compared with the one of heifers, and the highest percentage of infections due to PI-3 virus in all groups of the animals. With respect to viruses and districts under study, the following indices of infections were found: BHV-1 from 6.2 to 44.4 per cent, PI-3 from 32.7 do 69 per cent, BHV-4 from 13.9 to 40 per cent, BRSV from 8.5 to 44.4 per cent and BVD from 8.5 to 27.7 per cent. The results indicate significant differences in respect to virus infections caused mainly by the home and international market of cattle. It is worth mentioning that mixed infections were observed more often than monoinfections.