Abstract: This study is to determine the most effective inoculation mode and the distribution of infectious bovine rhinotracheitis virus (IBRV) in experimental animals, which is used to evaluate the protective efficiency of attenuated vaccine strain LNM. 9 cows post-ablactation were divided into test groups (nasal sprays group, nasal drops group) and control group, each group contains 3 cows. Test groups were inoculated with virulent strain of LN01/08 by nasal sprays and nasal drops, respectively, and the data of daily clinical symptoms, body temperature and nasal swab were collected for consecutive 14 days post-inoculation. Experimental animals in different clinical period post-onset were killed and main internal organs were collected for virus isolation. The test results showed that all animals post-inoculation developed different extent clinical signs (the nasal spray group animals performed more seriously), and IBRV were most distributed at tissues of respiratory and ocular conjunctiva. It is concluded that experimental animals inoculated with IBRV by nasal sprays was better than that by nasal drops, which could provide a basis for develop IBR vaccine and evaluate immune effect of IBRV vaccine.

Key words: infectious bovine rhinotracheitis virus; challenge