The best defence against calf disease is to implement sound biosecurity measures and hygiene practices on the farm and around the calf shed.
Dairy hygiene specialist Gavin Smedley, from Tasman Chemicals, said attention to detail in this area was critical to successful calf rearing.
‘‘Healthy calves also stay in the herd longer as milkers than those who experience disease,’’ Mr Smedley said.
‘‘Farm biosecurity is essentially a set of measures designed to protect a property from the entry and spread of pests and diseases.
‘‘This includes restricting access by other livestock and personnel.’’
Mr Smedley said there were several ways to improve biosecurity on-farm:
Restrict access to the calf shed to only those responsible for rearing calves. Put measures in place for high-risk visitors such as veterinarians, operators of mobile calf scales, other farmers and service providers who have access to other calf facilities.
Separate and clean clothing/boots:
Attend each shift with clean clothing and boots.
Practise regular hand washing and footwear disinfection before and after visiting the calf shed.
Housing of purchased calves:
Ensure that all calves purchased off farm are housed separately to the home calves. Same applies to sale calves.
Set up a dedicated area for sick calves downwind and away from the general calf population to reduce contact between healthy and sick animals.
Stock movement: Collect and deliver calves in clean trailers and trucks.
Dead stock removal: Pick up dead stock away from the calf shed.
‘‘Hygiene is an important part of biosecurity. As the saying goes, cleanliness is next to godliness — but in many cases the basics are often overlooked.
‘‘Reducing the risk of infection through meticulous hygiene in calf housing, management and handling is of utmost importance.’’
Hygiene practices for successful calf rearing include:
Dip or spray navel with iodine after birth. This prevents pathogens tracking up the navel cord and causing infection.
Regular cleaning and disinfection of the ute tray or trailer used to transport newborn calves.
Disinfect footwear on entering or exiting the calf shed.
Always work from youngest to oldest:
Workers’ hands and clothes become contaminated and can transmit infections between calves. Never work with sick calves and then move onto healthy or newborn calves.
Feeding equipment disinfection:
Pathogens that cause disease in calves can survive and multiply in milk and dirty equipment. Calf-feeding equipment must be kept immaculately clean at all times.
Make sure calf pens are thoroughly cleaned and disinfected with a terminal disinfectant (e.g. ViralFX) before calving and between batches. Spraying and fogging on a regular basis while calves are in the pens will reduce pathogen load and prevent disease. It is important to note that 90 per cent of cleaning is achieved by the physical removal of organic debris. Disinfectants do not work properly in the presence of dirt, milk residue and manure.
Clean and dry bedding:
The absence of moisture makes life difficult for pathogenic organisms to thrive. Ensure there is good drainage, the provision of fresh bedding between batches and regular top-ups in between to keep the bedding clean and dry. Use of non-irritant desiccants (e.g. Deltasec) to absorb moisture will help keep bedding fresh.