Effects of subclinical bovine leukemia virus infection on fertility of Holstein cows and heifers

摘要

The purpose of this study was to determine the serological prevalence of bovine leukemia virus (BLV), and describe whether there are effects of BLV infection on the fertility of dairy cattle in Burdur, Turkey. The study population was 182 clinically healthy Holstein cows (>2-years-old) and 81 heifers (17- to 20-months-old) from a commercial dairy herd in Burdur. BLV prevalence was 66.48% (121/182) and 62.96% (51/81) in cows and heifers, respectively. There were no significant differences between BLVantibody-negative and antibody--positive cows for days open (DO; P = 0.2567) or between BLV antibody-negative and antibody-positive heifers for first service age (FSA; P = 0.65). Moreover, differences in conception rates (CR) between BLV antibody-negative and antibody-positive cows or heifers were insignificant (P > 0.1). In conclusion, even though the prevalence of BLV infection in Burdur region was found to be high, no effect of BLV infection was detected for fertility.