The Effect of Infection with Bovine Viral Diarrhea Virus on the Fertility of Cows and Heifers

In the current study, blood samples from 319 cows and heifers were studied. Antibodies against BVDV infections in serum samples and BVDV antigens in leukocytes were present in 203 (148 cows and 55 heifers) and 56 (28 cows and 28 heifers) samples, respectively. Although no significant difference was detected between seropositive ŠBVDV (Ag-/Ab+)1 and uninfected ŠBVDV (Ag-/Ab-)1 cows and heifers at the time of the first insemination (FIT), first service age (FSA) or conception rate (CR) (p>0.05), the difference in age of seropositive and infection free cows differed significantly (p<0.05). Furthermore, differences in FIT, FSA or age of seropositive and uninfected pregnant cows and heifers did not differ significantly (p>0.05). Differences between persistently infected ŠBVDV (Ag +/Ab -)1 and uninfected cows for FIT, CR and age were statistically different (p<0.001). On the other hand, the difference between persistently infected and uninfected heifers for FSA or CR did not differ significantly (p>0.05). Even though, FSA of pregnant persistently infected or uninfected heifers was not different (p>0.05), there was a difference between the age and FIT of persistently infected and uninfected cows (p<0.001). However, pregnancy was not detected in any of the persistently infected cows. In conclusion, seropositivity for BVDV did not affect fertility of cows or heifers. Although, differences in fertility between persistently infected and uninfected pregnant cows and between persistently infected and uninfected non-pregnant cows were present, fertility of heifers was not affected by BVDV persistency.