POTENTIAL RISK-FACTORS FOR CRYPTOSPORIDIUM INFECTION IN DAIRY CALVES

Fecal samples from 7,369 calves on 1,103 farms were examined for crypt osporidia in a nationwide survey, using monoclonal antibody technique. Cryptosporidium oocysts were found in calves from 652 (59.1%) of the farms and in 1,648 (22.4%) of the tested calves. Almost half the calve s between 7 and 21 days of age had cryptosporidia in their fecal sampl es. Prevalence was highest during the summer. Farms with multiple-cow maternity facilities and farms with > 100 milking cows were the most l ikely to have calves with cryptosporidia.