Causes: Caused by a number of infectious microbes including viruses Rotavirus and Coronavirus, Protozoa including Cyrptosporidia and Coccidiosis and bacteria including Salmonella sp and a variety of strains of E coli.
Conditions when likely to occur:
- First six weeks of life.
- Calves from heifers and cows with low immunity.
- Incidences of severe copper or selenium deficiencies.
Healthy young calves often carry pathogens and amplify environmental contamination and adult cows can be asymptomatic carriers of pathogens that infect young calves.
All major pathogens can survive in the environment, especially when it is cool and damp.
Close contact, poor hygiene and high stocking rates of young calves are likely to increase the risk of infection.
Infections are likely to be more severe when herd nutrition is poor and calves receive low levels of colostrum. Calves should consume 10% of their bodyweight of colostrum in the first 24 hours of life.
Calving heifers on the same area every year should be avoided and cows and calves removed from contaminated areas to reduce the risk of infection of young calves in the face of an outbreak.
New cattle should no be exposed to calves in case they carry new pathogens
Clinical signs: Calf depressed may have elevated temperature, scouring with or without blood, dehydrated, calves dead.
Faecal samples for detection of all important pathogens.
Management strategy to prevent disease:
Develop and implement a farm biosecurity plan.
Minimise contact between young calves and reservoirs of infection:
- Short calving period to avoid late young calves been exposed to contaminated pasture.
- Select low risk calving paddocks especially avoiding contaminated heifer paddocks.
- Drift off calves after three weeks.
- Provide clean water and avoid.
Maximise colostrum intake of calves:
- Calves should consume 10% of their bodyweight of colostrum in the first 24 hours of life.
- Good nutrition is essential to ensure good colostrum production, especially in heifers.
- Calves from a difficult birth, especially in heifers should receive colostrum at about 1L/20kg birthweight by stomach tube.
- Implement strategies to minimise dystocia rates in heifers.
- Vaccination for entero-toxic E coli or salmonella may be considered if diagnosed.
Prevent the introduction of new pathogens to the calving herd:
- Do not replace dead calves with bobby calves.
- Avoid exposure of calves less than six weeks of age to new stock.
Avoid grazing young calves on water courses from heavily contaminated adjoining properties.