The present study determined the milk value rather than serum in diagnosis of toxoplasmosis in goats using ELISA and Modified Agglutination Test (MAT). ELISA proved to be more specific and sensitive (92% & 85%), than MAT (90% & 80%) in diagnosis of Anti-T. gondii Antibodies (ATAb) in group of microscopically proved T. gondii aborted goats respectively.
There was a direct relationship between the mean ELISA O.D. value and the level of Ab-titer in MAT positive sera. The overall prevalence of infection in 600 serum samples from grazing goats was 22% and 20% after examination using ELISA and MAT respectively. It was lower after examination of their milk (20%) and (18%) by both techniques respectively. ATAb were significant high in serum (P < 0.05) during January, February and March, decreased significantly in April (P < 0.05) till August, then significant increased (P < 0.05) from September to December using ELISA. In time where ATAb were present by different levels among the whole year in serum, it didn't diagnose in milk from June to September. The infection was high in Egyptian Baladi breed in serum and milk (30% and 27%), while the Barki breed was the lowest one (13.33% and 12%) respectively. High rate of infection (30% in serum and 27% in milk) was recorded in goats > 2 years old, while no ATAb could be detected in goats less than one year old. The highest prevalence of infection (39.28% in serum and 37.14% in milk) was in Qalyoubia, the lowest one (11.25% & 9.58%) was in Giza governorate. The prevalence of infection was high after examination of serum and milk of goats with previous history of abortion in comparison with the other goats.