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  • Author or Editor: James A. Harp x
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Abstract

Objective

To determine whether periparturient cows or contact surfaces to which newborn calves are exposed are reservoirs of Cryptosporidium parvum oocysts.

Animals

Periparturient cows and their calves.

Procedure

Using direct fluorescent antibody (DFA) and acid-fast (AF) assays, fecal samples taken before and after calving from periparturient cows were tested for C parvum oocysts. Fecal samples from calves were collected every other day from age 7 to 21 days and were tested by use of the AF assay. Topsoil from close-up and maternity pens and scrapings from wooden walls and floors of calf hutches were tested for C parvum oocysts by use of DFA assay.

Results

None of the 384 fecal samples obtained 1 to 21 days before or after calving or on the day of calving from 154 periparturient cows contained detectable C parvum oocysts. Despite this lack of detectable periparturient shedding, the period prevalence of calfhood infection was 92% (123/134) from age 7 to 21 days. Soil samples from the close-up and maternity pens where newborn calves spend the first 12 hours of life also were negative for C parvum oocysts. Wood scrapings from the outer 2 mm of the walls and floors of empty and cleaned calf hutches that were ready to receive calves were C parvum oocyst-positive.

Conclusions

Conditional on sensitivity of DFA, periparturient cows did not appear to shed detectable C parvum oocysts. In contrast, the floors and walls of wooden calf hutches contained detectable C parvum oocysts on the surface. (Am J Vet Res 1998;59:1116-1121)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To test the ability of oral vaccination or probiotic treatment with lactic acid-producing bacteria to protect calves from Cryptosporidium parvum infection under field conditions.

Animals

134 Holstein calves born on a dairy farm where cryptosporidiosis was endemic.

Procedure

Calves were randomly assigned to 1 of 3 treatment groups at birth. Calves in the vaccine group received an oral dose of C parvum vaccine within several hours of birth. Calves in the bacteria group received an oral dose of lactic acid-producing bacteria daily for the first 10 days after birth. Control calves were not treated. All calves were monitored for diarrhea and fecal shedding of C parvum oocysts for 3 weeks.

Results

There were no significant differences in the incidence of diarrhea and oocyst shedding among the 3 groups.

Conclusions

Neither vaccination nor probiotic treatment was effective in preventing C parvum infection in calves under field conditions. High numbers of C parvum in the environment may have overwhelmed any potential benefits of these regimens. Further work is necessary to develop effective prophylaxis against C parvum under field conditions. (Am J Vet Res 1996;57:1586–1588)

Free access
in American Journal of Veterinary Research