Serological study of bovine herpesvirus type 1 and parainfluenza type 3 in cow farms of Qazvin province based on different ages and seasons

The main objective of this study was to estimate the seroprevalence of bovine herpes virus type 1 andparainfluenza type 3 in a non-vaccinated population cattle in the livestock region of qazvin province.totally 504 sera were randomly collected and tested from 8 industrial dairy farms in qazvin provinceduring march 2010-march 2011. the result of one way analysis of variance was used for the analysis data.also tukey method was employed to detect pair wise differences among the ages determined that therewere a significant differences among the average titer in 1 to 3, 1 to 4, 2 to 3 and 2 to 4 year cows (p < 0.005,p < 0.001, p < 0.041, p < 0.001). due to the significance at the different titers, and comparing pair wise amongdifferent seasons tukey,s method had been used and showed significant difference in summer with autumn(p < 0.038 ) and winter (p < 0.001). a chi-square test showed the significant differences among ages(p=0.001). the sero- prevalence of bhv-1 was estimated to be 7.1% with 1.2% standard error (se). theresult of pi3 showed the significance at the different titers comparing with the different seasons. thereforetukey,s method had been used and showed significant difference among seasons (p < 0.001). the seroprevalenceof pi3 was estimated to be 95% with 1% se.