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Calf Scours


Calf scours (diarrhoea) is the nightmare of every calf rearer. Once it is in your shed it is almost impossible to get rid of during calving season and it causes a lot of extra work and frustration. It has a high economic impact as usually many calves are affected and of those a high percentage may die if not treated promptly. On top of that calves that recover have a higher risk of poor growth and poor lifetime performance.

Calves are affected up to 4-6 weeks of age and the major causes are Rotavirus, Cryptospirosis, E. Coli and Coronavirus. Most of these culprits are carried by adult cows which don’t show any symptoms, but can infect their calves during and after calving.

Cryptospirosis and Campylobacter are contagious to humans so always make sure you have strict personal hygiene when you deal with calf diarrhoea! Be very careful with children around the calf pens, especially if diarrhoea is present.



Initial selection criteria need to be clear to produce good strong calves. Start with a strong healthy calf.

Treat navel with an approved iodine solution immediately after birth and following transportation to prevent infection.

Colostrum intake is very important and it is not as easy as it sounds. First of all you need to have good quality colostrum and second of all calves need to get 3-4 litres within six hours of birth which rarely happens. Research shows about 50% of New Zealand calves do not get enough.

Feeding hygiene and routines: good quality colostrum is needed. Don’t give penicillin milk to younger calves and be very careful with mixing and storing milk powder; always follow the manufacturer’s instructions. Feeding equipment should be cleaned on a regular basis.

Clean fresh water and a fibre source (hay or straw) must be available from day one.

Ensure feed increases/changes are made gradually. If required only make changes every three days.

The same person(s) should feed the calves at the same time each day. Caring quality staff is important.

Housing: no overcrowding; the rearing area must be kept dry and draught free and calves must be dry at all times. Shelter should be available for all calves; best is an open ended barn with the open end away from the prevailing wind and adequate ventilation is essential. There should be no smell of manure gases.

Ensure adequate bedding (bark/straw/sawdust/woodchips) is provided and topped up regularly.

Ensure good hygiene programme: spray the barns with a complete antiviral product twice a week and daily for sick calves.

Control rodents and birds and do not allow dogs to wander from pen to pen.

No mixing of calves from different ages: ensure an ‘all-in/all-out policy’ and disinfect pens between batches of calves.

Vaccination of mature in-calf cows 3-12 weeks before calving. This vaccination boosts the antibodies against Rotavirus, Coronavirus, E.Coli and/or Salmonella in the colostrum and have proven to be successful. However calves need to drink this ‘superboosted’ colostrum within six hours of birth for it to be effective.



First of all it is important to know what causes the diarrhoea: a vet visit is necessary to see and treat the sick calves and to take poo samples. Once we know what causes the problem we can order in powder with antibodies specifically made for the disease(s) on your farm. You can add this to the milk for 3-5 days for sick calves and also use it as a prevention for new calves coming into the shed.

Sick calves will need treatment as they can get dehydrated and go downhill very quickly. Please contact our clinic if you have any calves with diarrhoea.

Good system in place for identification, treatment and housing of sick calves: a separate pen for sick calves is an absolute must and calves with diarrhoea should be removed immediately from the healthy calves. Sick calves always need to be fed/treated last and all equipment used in the sick pen (including gumboots) need to be thoroughly cleaned after each use. Feeding equipment for sick calves should not be used for healthy calves.