Overføring av smittestoffer fra ku til kalv i melkefôringsperioden - en litteraturstudie

Summary

The purpose of this literature review was to
evaluate if it should be avoided to keep the cow
and calf together after birth because of the risk of
transmission of infectious pathogens from the cow to
the preweaning calf. The sources of transmission of
common infections in newborn calves are described.
E.coli, rotavirus, bovine coronavirus, Clostridium spp.,
Cryptosporidium spp., Giardia and Eimeria spp. are
ubiquitous, and infected calves can excrete extreme
numbers of microorganisms and cause contamination
of the environment. According to the literature, microorganisms in the environment represent a higher risk
than adults for transmission to the newborn, and hygienic
measures and good passive immune status of the
newborn are important prophylaxes. Transplacental
transmission of bovine virus diarrhea virus may cause
persistently infected individuals, which represent the
most important route of viral shedding. Mycoplasma
bovis usually cause infection in newborn calves with
the pathogen often transmitted from the environment.
The importance of the cow for direct transmission to
the calf is dubious. Resent research has demonstrated
that Mycobacterium avium subsp. paratuberculosis
can be spread by bio-aerosols, and that intrauterine
infection is quite common. Some authors suggest that
separation of the dam and calf might be less effective
in preventing the spread of this infection than previously
anticipated. The authors’ conclusion is that cows
in Norway do not represent a greater risk of transmission
of pathogens to the newborn calf than the other
calves and young animals in the herd.