Association of passive transfer of immunoglobulins and hematologic analytes with Cryptosporidium spp. infection in Holstein calves

Cryptosporidium spp. is a major pathogen of neonatal calf diarrhea. The aim of the present study was to assess the association of Cryptosporidium spp. infection with passive transfer of immunity and several hematologic analytes in neonatal Holstein calves, with repeated measurements from each calf. Fifty-eight calves from three dairy farms were enrolled in the study. Fecal specimens, for Cryptosporidium spp. oocysts detection, and blood specimens, for total proteins concentration (to assess passive immunity status) and a complete blood count measurement, were obtained from each calf at 2, 4, 6, 15 and 30 days after birth. Twenty-one out of the 58 (36.2%) calves were infected in at least one sampling day. Infected calves began excreting oocysts from as early as day 2 and 4. An association between higher total protein (TP) values and Cryptosporidium infection was observed. Calves excreting Cryptosporidium spp. oocysts at sampling day 6 had significantly higher TP concentration at sampling days 2 and 4 (P=0.017 and 0.034, respectively). Moreover, Cryptosporidium spp. infected calves at sampling days 2 and 4 had significantly lower hemoglobin (HGB) values at day 2 (P=0.023 and 0.04, respectively). Cryptosporidium infection was also significantly associated to a rise in fibrinogen (FIBR) concentration, as well as in neutrophil and eosinophil counts. The present findings suggest that adequate passive transfer of immunoglobulins is not protective against cryptosporidiosis. Finally, low HGB in neonates may predispose to Cryptosporidium spp. infection.