Abstract

In order to investigate the infection dynamics of Cryptosporidium bovis and C. ryanae, a two-year prospective cohort study was performed on a dairy farm known to be free of C. parvum. Sixteen calves were recruited when newborn. Faecal samples were collected weekly until calves were nine weeks old, then monthly until calving or culling. Samples (n = 455) were examined by fluorescence microscopy, and when positive the species were determined by DNA sequencing. In calves up to nine weeks, C. bovis was found in 58.5% of the samples, C. ryanae in 9.2%, and both C. bovis and C. ryanae in 3.1%. The prevalence of shedding calves peaked at 87.5% in week five, which is earlier than many international studies have shown for C. bovis. The cumulative incidence of C. bovis reached 100% when the calves were five weeks old. In four calves, the species detected changed from C. bovis to C. ryanae or the other way around, and two samples were a combination of both species. Several individuals shed oocysts sporadically up to 16 months of age. The highest oocysts per gram faeces count was seen in week three (3.6 x 10(6) OPG). Diarrhoea was not associated with oocyst shedding.

Keywords

Longitudinal; Prospective; Calf; Heifer; C. bovis; C. ryanae

Published in

Veterinary Parasitology: Regional Studies and Reports
2020, Volume: 20, article number: 100400
Publisher: ELSEVIER

SLU Authors

• Åberg, Malin

  • Department of Clinical Sciences, Swedish University of Agricultural Sciences
    

• Emanuelson, Ulf

  • Department of Clinical Sciences, Swedish University of Agricultural Sciences
    

• Björkman, Camilla

  • Department of Clinical Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Clinical Science


Publication identifier

DOI: https://doi.org/10.1016/j.vprsr.2020.100400

Permanent link to this page (URI)

https://res.slu.se/id/publ/123145