Background
Toxoplasma gondii causes reproductive losses in sheep worldwide, including Australia. The reproductive performance of primiparous ewes is typically lower than for mature, multiparous ewes, and younger ewes are more likely to be immunologically naïve and therefore more susceptible to reproductive disease if T. gondii infection occurs during pregnancy. The
Conclusions
Low frequency of detection of T. gondii seroconversion during gestation and low frequency of seropositivity to T. gondii suggests that toxoplasmosis was not an important contributor to reproductive losses in primiparous ewes on farms located over a wide geographical area in southern Australia.
Results
Toxoplasma gondii seropositivity using indirect ELISA was detected at 16/28 farms located across southern Australia. Apparent seropositivity to T. gondii was lower in primiparous ewes (1.1, 95% confidence interval (CI) 0.6, 1.8) compared to mature, multiparous ewes (8.1, 95% CI 6.0, 10.5; P < 0.001). Toxoplasma gondii seroconversion during the gestation and lambing period was confirmed for 11/1097 (1.0, 95% CI 0.5, 1.7) of pregnant primiparous ewes that failed to raise a lamb, and 1/161 (0.6, 95% CI 0.1, 2.9) primiparous ewes with confirmed mid-pregnancy abortion. Conclusions: Low frequency of detection of T. gondii seroconversion during gestation and low frequency of seropositivity to T. gondii suggests that toxoplasmosis was not an important contributor to reproductive losses in primiparous ewes on farms located over a wide geographical area in southern Australia.