University of Tehran Press Journal of Veterinary Research 2008-2525 59 2 2004 07 22 - - 11987 FA Journal Article 1970 01 01 Objective: To determine serological prevalence rate of infection of sheep with IBR virus in Chaharmahal-Bakhtiary province. Design: Cross - sectional study. Animals: Four hundred and two healthy sheep. Procedure: Serum samples were collected from 402 sheep during four seasons of 2002-2003 in all townships of Chaharmahal - Bakhtiary province by cluster random sampling method. Charactristics of the animals (age, sex and history of abortion) were recorded. Sera were tested for antibodies against IBR virus by the serum neutralization test. Statistical analysis: Chi-square, Linear regression. Results: Serum samples from 43 (10.7%) sheep were positive. Prevalence rate of seropositive animals in all 5 townships of the province was estimated. No relationship was found between township, sex, season, previous record of abortion and IBR infection in sheep. Linear regression test indicated a relationship between age and prevalence rate of infection (r = 0.94). Objective: To determine serological prevalence rate of infection of sheep with IBR virus in Chaharmahal-Bakhtiary province. Design: Cross - sectional study. Animals: Four hundred and two healthy sheep. Procedure: Serum samples were collected from 402 sheep during four seasons of 2002-2003 in all townships of Chaharmahal - Bakhtiary province by cluster random sampling method. Charactristics of the animals (age, sex and history of abortion) were recorded. Sera were tested for antibodies against IBR virus by the serum neutralization test. Statistical analysis: Chi-square, Linear regression. Results: Serum samples from 43 (10.7%) sheep were positive. Prevalence rate of seropositive animals in all 5 townships of the province was estimated. No relationship was found between township, sex, season, previous record of abortion and IBR infection in sheep. Linear regression test indicated a relationship between age and prevalence rate of infection (r = 0.94). https://jvr.ut.ac.ir/article_11987_25362c2518dce7c8099eaec4ce8671b9.pdf