Associations between reproductive performance and seropositivity for bovine leukemia virus, bovine viral-diarrhea virus, Mycobacterium avium subspecies paratuberculosis, and Neospora caninum in Canadian dairy cows

Herd-level risk factors for infection with bovine leukemia virus in Canadian dairy herds

“…8% (15.8-27.0%). Similar studies (also forming part of the database for the current study) revealed a high herd-level prevalence of BLV infection across Canada (VanLeeuwen et al, 2005aScott et al, 2006). Measured at the herd level, the direct production losses from EBL in the Maritime Canadian provinces have been conservatively estimated at $806 per year in an average 50-cow herd (Chi et al, 2002).…”

Neospora caninum: Seroprevalence in beef cattle in the mountainous region of Santa Catarina, Brazil

“…However, individually, beef cattle, presented higher seropositivity. In comparison, Vanleeuwen et al (2006) observed a higher seroprevalence of neosporosis in cattle beef herds than in dairy herds in Canada, but no difference was observed in the case of individual animals. These authors concluded that these differences may be partly due to employee tests to laboratories where they performed the tests or both, which can make inappropriate statistical comparisons in certain situations.…”

Control of infectious diseases in dairy cattle

“…N. caninum-seropositive cows had a 1.27 times higher odds of having a calving interval > 484 days compared to N. caninum-seronegative cows. Also, an interaction between N. caninum and BVD was observed with respect to first service to conception interval, with odds ratios of 0.64 and 1.06 for N. caninum-seropositive cows (compared to N. caninum-seronegative cows) in BVD-seronegative and BVD-seropositive herds, respectively (VanLeeuwen et al, 2010).…”