Title:A szarvasmarhák légzőszervi tünetegyüttesének (BRDC) és hajlamosító tényezőinek előfordulása nagy létszámú magyarországi állományokban
Summar y The authors surveyed 15 large-scale Hungarian cattle herds (13 dairies and 2 beef herds) in 2013 in terms of environment, management and housing of calves, and the prevalence and prevention of Bovine Respiratory Disease Complex (BRDC). In all the surveyed dairy herds the following risk factors were identified; overpopulation, dehorning, previous BRDC cases and lack of the all in/all out system and grazing. On most farms the implementation of the biosecurity measures (e.g. quarantine) was not proper. At the time of the survey in 80% of the herds the BRDC was present with different severity, mainly in the calves aged from 3 to 6 month. The most prevalent clinical symptoms of the BRDC were cough, fever, heavy breathing, nasal and ocular discharge, and it caused decreased growth rate, death and reproductive disorders. The BRDC is a multifactorial disease, thus, beside a well-scheduled vaccination program the success of its prevention depends also on the environmental, housing conditions and the management of the farm.