Cryptosporidiuminfections in suckler herd beef calves

Abstract

SUMMARYA study was carried out to investigate how commonCryptosporidiuminfections are in beef calves in Swedish suckler herds and to explore which species and subtypes that occur. We further aimed at identifying factors associated with shedding ofCryptosporidiumoocysts in this type of calf management. The study was conducted in two regions in Sweden and included 30 herds. Faecal samples were collected from calves younger than 3 months. A brief clinical examination was done and a questionnaire was used to collect data on management routines. Faeces were cleaned and concentrated and oocysts identified by epifuorescence microscopy.Cryptosporidiumpositive samples were analyzed at the 18S rRNA and GP60 genes to determine species andCryptosporidium parvumsubtype, respectively. Logistic regression was used to identify factors associated with infection. Oocysts were detected in 122 (36·7%) calves from 29 (97%) herds, at 400 to 2·4 × 107OPG. The youngest positive calves were only 1 and 2 days old. There was no association between age andCryptosporidiuminfection.Cryptosporidium bovis, Cryptosporidium ryanae, C. parvumandCryptosporidium ubiquitumwere identified, withC. bovisbeing the major species. TwoC. parvumsubtypes, IIaA16G1R1 and IIdA27G1 were identified. Routines for cleaning calf pens and number of cows in calving pens were associated with infection.