Seroprevalence of Neospora caninum Infection in 25 Ontario Dairy Herds and its Association with Periparturient Health and Production
DOI:
https://doi.org/10.21423/bovine-vol35no1p8-12Keywords:
animal health, antibodies, dairy herds, disease prevalence, milk productionAbstract
Serum samples were collected in 1995/1996 from 7 58 animals on 25 Ontario Holstein dairy farms at three weeks prior to expected calving. The frozen sera were subsequently analyzed for anti-Neospora caninum antibodies. Herd seroprevalence was 60% and 73% using two different cut-off values for defining infection. Using the lower cut-off, within-herd seroprevalence ranged from Oto 38% with a mean of 9.0% in seropositive herds. Seropositivity was associated with a 3.8-fold increased risk ofretained placenta. No significant impact of infection on milk production was detected for the first three Dairy Herd Improvement test-day evaluations of each cow's lactation.