To prevent disease spread on farm

Avoid bringing in new disease (avoid buying in animals, take best-practice biosecurity measures if buying in animals is absolutely necessary).
Prevent animals getting sick by optimising husbandry and management on the farm (see section on Husbandry).
Develop a herd health plan with your vet which should include vaccination protocols where appropriate.
Carry out regular routine herd disease testing – discuss which tests are appropriate with your veterinary practitioner.
Diagnose and treat sick animals promptly. Animals should me observed regularly (at least daily) or diseases may become advanced before they are detected.
Isolate or remove sick animals from the group/herd.
Isolating aborting cow/s from the herd.
Isolation/sick pens should not be used to house healthy animals (i.e. sick pens should not also function as calving pens).

Maintain a hygienic environment that is cleaned regularly.
Ensure an appropriate stocking density.
Clean and disinfect contaminated housing.
Composting manure and storing slurry
Regularly empty and clean feed and water troughs.
Reduce equipment and machinery contamination by regular cleaning.
Ensure adequate ventilation in sheds – inadequate ventilation reduces air quality and predisposes to development of respiratory disease. See AHI Calf Rearing (PDF) and Calf House Management (PDF), Teagasc Calf Rearing Manual for more details.

Use clean and disinfected equipment.
Use separate equipment for different groups.
Best practice is to change needles between animals, at a minimum change needles and syringes between different groups of animals.
Disinfect boots and change gloves between different groups of animals.
Raise and shield feed, water troughs and mineral blocks to prevent contamination with manure and urine.

See AHI and Teagasc published guides for detailed information on how to prevent disease spread on your farm.