It has been well established that calf rearing/replacements are the second biggest cost on dairy farms after feed bills.
This begins as soon as the calf touches down on the farm. In my experience, the first 10 to 12 weeks pre-weaning is the most critical period for calves' health.
An animal's ability to fight disease depends on a functioning healthy immune system which reduces exposure to diseases.
A calf is born without a functioning immune system so it must develop it by receiving the first milk or colostrum from its dam.
This rich yellow milk is full of immunoglobulins (antibodies) which are large proteins. When absorbed by the calf these help it fight infections. A calf who fails to receive these antibodies has no active immune system to fight off disease.
There are some important areas to focus on when managing this 'liquid gold' (colostrum).
Firstly we need to ensure it's the first milk from the cow and that it is of good quality.
We can test colostrum quality on farm using a refractometer. Remember that if bacteria contaminate colostrum then it can lead to poorer absorption. So hygiene is critical when handling and storing colostrum.
The next issue to focus on is the quantity of colostrum a calf receives - this should be three litres or approximately 15pc of body weight in the first feed.
Sometimes this requires milking out the cow and getting the calf to suckle from a bottle.
Unfortunately, natural suckling has been shown in studies to deliver variable and often inadequate intakes.
For weak calves or where calves are being snatched and removed to calf pens - to reduce exposure to infections -stomach tubing offers a good and reliable way of ensuring intakes.
The next issue to get right is timing - the colostrum must be got into calves as quickly as possible; the golden rule is within two hours of birth or at the very latest within six hours. A calf's ability to digest these large proteins drops by the hour and after 24 hours they can absorb none.
Think of the entire process in terms of steps 1, 2, 3 - first milk within two hours of birth and three litres of volume.
While there are many synthetic products on the market nothing beats the real thing. Always have a store of colostrum from Johnes-free cows available in your freezer in flat bags to allow easy thawing.
When thawing do it slowly below 50°C and never use a microwave.
After getting the colostrum right, the next area to focus on is calf nutrition. There is no doubt calves respond to feeding in their first weeks.
A calf will naturally suckle 6-12 litres/day if left with the dam. With this in mind, especially when feeding whole milk, the minimum amount of milk to be fed should be three litres twice daily.
On many calf health visits I have seen where increasing feeding alone can make huge differences to calf health and vigour.
The energy milk provides heifer calves in the first weeks
of life impacts growth and has even been shown to affect lifetime milk production.
With the removal of quotas, many farms now feed milk replacer to calves. When fed correctly - in terms of timing, and volumes - it can be an excellent way of rearing calves.
My experience is that effort should be put into sourcing a good quality milk replacer.
Look at a whey protein base with a crude protein for heifers above 22pc. Keep crude fibre between 0-0.15pc; fat/oil between 18-20pc and crude ash between 7-9pc.
It is worth spending time finding the right replacer, mixing at the right temperature, volume and amount (750-900g of milk solids/day should provide 0.7-1 kg of growth a day)
After getting milk feeding right, farmers will go to once a day milk feeding after four to five weeks or start reducing intakes to help promote concentrate intakes.
This is important for rumen development and helps the calf transition or wean from milk at 10-12 weeks.
It is the carbohydrates in concentrates that are critical to a healthy rumen developing and these should be available from Day 4 onwards.
My preference is for a coarse ration with plenty freely available water from birth. It is recommended that for every 1kg of concentrates, a calf should consume 4.5 litres of water. Every calf should have fresh clean water available from birth.
While forages can be fed, a chop length 2.5cm in raised feeders is recommended to avoid faecal contamination.
I have often seen under-feeding contribute to immune suppression and increased susceptibility of young calves to disease so getting nutrition right is essential. Waste milk should never be fed to calves.
Tommy Heffernan runs a veterinary practice in Avondale, Co Wicklow