Prevalence of antibodies to bovine herpesvirus type-1 in the Lithuanian cattle
1998
Salomskas, A. | Tamasauskiene, B. (Lithuanian Veterinary Institute, Kaisiadorys (Lithuania)) | Scerbavicius, R. | Remeikis, A.V. (National Veterinary Laboratory, Vilnius (Lithuania))
Preliminary serological investigations carried out in 1992-1993 at bull-growing stations in Lithuania showed that 25 per cent of calves tested were seropositive for infectious bovine rhinothracheitis (IBR). On the basis of these results the Lithuanian control programme for infectious bovine rhinotracheitis/pustular vulvovaginitis (IBR/IPV) eradication in breeding cattle was approved. In 1994 and 1995, after seropositive animals had been eliminated from the stock, only 5.7-5.9 per cent of calves tested were seropositive. However, investigations in 1996 showed that 66.1 per cent of high productive dairy cows were IBR seropositive. Blood serum analysis in the four largest and two smaller Lithuanian artificial insemination (AI) centres revealed that before the control program for IBR started in 1993, 49.8 per cent of AI bulls were infected with bovine herpes virus type 1 (BHV-1). On these farms, the IBR eradication program was most strictly implemented and as a result in 1996 only 3.5 per cent of 257 tested animals were seropositive. In 1993 semen samples of 65 seropositive bulls from AI centres were examined and in 16.9 of these cases BHV-1 was isolated. In 1994 and 1995, only 5.3 per cent and 2.8 per cent of the semen samples were BHV-1 positive, respectively. The viruses most frequently found in cases of bronchopneumonia were parainfluenza-3 (61.8 per cent of seropositive samples) and BHV-1 (26.4 per cent of seropositive samples). Bovine viral diarrhoea and respiratory syncytial virus infection were serologically diagnosed in 15.4 per cent and 13.9 per cent of investigated calves, respectively
显示更多 [+] 显示较少 [-]