This study was performed to investigate experimental transmission of Cryptosporidium parvum in a calf. A 25-day-old Korean native calf was inoculated per os with 1 x 10(6) C. parvum oocysts isolated from a Korean mouse. The calf commenced oocyst discharge in feces on post-inoculation day 4, and continued until the day 11. The number of discharged oocysts peaked (4.9 x 10(5)) on post-inoculation day 6. However, the calf did not show signs of diarrhea. The present results indicate that C. parvum is cross-transmissible between the calf and the mouse.
