공주, 연기지역 젖소의 Neospora caninum 항체 양성율 및 갓 태어난 송아지의 감염양상 조사

To examine the seroprevalence of Neospora caninum (N. caninum) infections in cattle raised at farms where an abortion had previously occurred in Gongju city and Yeongi-gun of Chungnam Province, 280 head of cattle from six farms were examined by ELISA. Thirty-two pregnant cattle from four farms were examined to determine the abortion rate in N. caninum-infected pregnant cattle and the infection pattern in newborn calves. The six farms where the abortions had previously occurred demonstrated positive reactions to N. caninum. Although the mean seropositive rate of the six farms was 17.5%, the range of seropisitivity was 3.4-57.1% due to the difference in seroprevalence between farms. The general pattern of seropositivity in cows was higher than in heifers. In addition, the abortion rate of N. caninumpositive in 18 out of 32 pregnant dams raised in four farms was 16.7%. The seroprevalence of newborn calves from N. caninum-positive pregnant animals differed according to the farm but was 86.7% overall. In contrast, 14 newborn calves from the N. caninum-negative pregnant cattle showed negative responses. This suggests that N. caninum is endemic and occurs through vertical transmission from chronically-infected dams. Therefore, aborted dams should be discarded.