Salmonella is very contagious and can have a high death rate. Calves are infected when they eat salmonella bacteria, which can be present in the environment, feed, or water.
External factors are required to allow infection to take hold – usually lack of colostrum, poor weather or housing, close contact with other infected calves, poor disinfection procedures or bringing in carrier calves. Carrier calves are bought in calves that have met salmonella strains that they have no immunity to and have been stressed during transport. The new strain of salmonella is brought onto your property and because the new calf’s immunity isn’t strong it can take hold and work its way through the shed.
As with most calf diseases getting adequate colostrum into calves is the best prevention. On farms that have had salmonella outbreaks in the past, vaccinating cows pre-calving helps to boost antibodies in colostrum.
Maintaining good hygiene practices in the calf shed will reduce the passing of infection between pens. Things to think about are:
Lastly, salmonella can cause diarrhoea in people so be careful of your own health and any children on your farm. Not drinking raw milk while salmonella is on your farm is important as salmonella can be in the milk. Practising the same hygiene practices for yourself is important-leave boots at the shed/away from the house, wash hands thoroughly and be conscious of how you are handling any dirty clothes.