Farmer Focus: How we battle crypto in our sheds

In seasonal spring calving systems, January hails the “big clean”. During the past week, we have been preparing calf sheds and calving pens to bring them up to scratch.

This entails more than just a simple power hose. As we have had issues in the past with cryptosporidiosis in calves, we looked at how we could best break the cycle of disease.

See also: How to tackle cryptosporidium in calves

About the author

Gillian O’Sullivan

Livestock Farmer Focus writer Gillian O’Sullivan milks 100 crossbred cows once-a-day with her husband Neil and father Michael on Ireland’s South-East coast. They operate a seasonal calving, grass-based system with milk supplied to Tirlán.

Read more articles by Gillian O’Sullivan

Crypto is so common that vets say it could account for 30-50% of calves with scour worldwide.

Calves pick up infection in the environment by ingesting a very small number of microscopic oocysts or eggs.

As few as 50-100 of these can set up infection within the gut of the calf, where they go through cycles of replication within the cells of the intestine.

Here is the where the trouble begins, as these replication phases within the gut turn 50 oocysts into millions. These are then excreted as scour, coating the calf housing in infective material.

They are not only highly infective, but come with military-grade cladding, making them highly resistant to disinfection. They can remain viable for about 18 months – hence the annual cycles of crypto on farms.

We have developed a two-pronged approach with good success. First, we vigorously power-hose all sheds and leave them to fully dry out.

We follow this with a foaming agent specifically designed to penetrate tiny remnants of dried-on calf muck. This is power-hosed off and again the shed is left to dry.

Once dry and clean as a whistle, a specific disinfectant aimed at excreted endoparasites such as crypto is applied.

Another way to go would be high-pressure steam cleaning, as temperatures over 60C are effective against crypto oocysts – but this equipment can be hard to find.

For me, this begins the year with a very low level of potentially infective material, but it is important to remember that completely eliminating every oocyst is virtually impossible.

Step two is to focus on colostrum quality. Calves are born with a naive immune system and depend on the uptake of immunoglobulins, or antibodies, from colostrum for passive immunity.

We harvest high-quality colostrum, test it and store it, ready to give to calves within two hours of birth.