Best practice colostrum management, combined with targeted vaccination and housing in the best environment, will provide the golden ticket to rearing healthy calves.
Building resilience in calves and lowering disease incidence is not only in farmers’ power, but can largely be achieved for free and by adopting a different mindset.
According to vet Kat Hart, of The George Vet Group, a lack of immunity has a lot to answer for in young calves, but is an area which can easily be tackled on-farm.
She says: “A third of heifers born don’t make it to second lactation. Most of those losses are pre-weaning and most of that is due to a lack of immunity.”
Most will be as a result of calves succumbing to pneumonia or scours.
In order to equip calves with the ability to fight off illness, a combination of top notch colostrum management, coupled with targeted vaccination is key to success.
This goes hand-in-hand with good environmental management to reduce disease pressure.
A newborn calf has none of its own immunity and is reliant on absorbing its dam’s best practice colostrum management, combined with targeted vaccination and housing in the best environment, will provide the golden ticket to rearing healthy calves antibodies through its colostrum.
This is termed as ‘passive immunity’. It provides a calf with protection until its own active immunity kicks in after a few weeks.
Ms Hart believes many farmers could benefit from placing more importance on feeding quality colostrum, at the right time.
She says: “It’s free. Farmers have colostrum there already. It’s a massively under-utilized resource I think. The hashtag #colostrumisgold’ is key.”
A calf’s ability to absorb colostrum declines over the first 24 hours (see graph, below) with under half of the gut ‘open’ to absorption at 12 hours. This means getting colostrum into them early is essential.
Ideally calves should receive a first feed of four litres or 10% of bodyweight within four hours of birth.
This should be followed with a further two litres within 12 hours of birth.
Vet Jimmy More, of Galloway Vets, believes timing is everything.
“Colostrum should not be fed ‘as soon as possible’ after birth. Feeding it to the calf very early in life is an absolute priority. ASAP suggests as soon as I’ve had my breakfast or finished milking,” he says.
Mr More adds there may also be some advantage to feeding colostrum over an extended period after this absorption window has shut, as the colostrum has a ‘lumen effect’ which helps the gut tackle diseases such as E.coli and rotavirus.
Colostrum quality varies markedly between dams. You cannot tell by eye, so testing is a must. Use a BRIX refractometer or colostrometer to establish quality and only feed colostrum with a BRIX reading of more than, or equal to, 22.
Ms Hart says providing clean colostrum should be a priority.
“You’re putting it into a naive calf with no immunity, so you don’t want to be giving them a bacterial soup.”
E.coli will typically double every 20 minutes if stored in a non-refrigerated, non-covered bucket. As the gut is an open door in the first 24 hours, any pathogens will go straight into the calf’s blood.
Cover and put a bucket of colostrum in a fridge for two to three days.
Freeze quality colostrum in a storage container with a high surface area to aid defrosting (such as a sandwich bag) and defrost as needed.
Vaccines increase antibody levels to a specific disease by stimulating an active immune response, without causing the development of the disease.
Vaccines will also reduce the amount of disease shed into the environment, which will help reduce disease pressure.
As passive immunity from colostrum wanes, by vaccinating, you are turning the tide so the calf’s own active immunity kicks in.
Often, vaccination strategy is only discussed with a vet when a farm has a problem. The aim should be to use them to prevent issues in the first place.
Whatever vaccines are used, adhering to the data sheet so they are stored correctly and given at the right time is essential. Otherwise they may not work.
There are several vaccines which can be given to the dam ahead of calving that act to increase antibody levels in colostrum, which the calf then consumes.
Mr More adds: “Enhancing antibody presence in colostrum via a vaccination programme may be advantageous, but must be discussed with a vet.”
Various vaccines are available to help protect the calf from pneumonia. Discuss appropriate strategy with your vet.
Good colostrum management should also be in place to ensure good uptake from colostrum when using dam vaccination strategies.
When it comes to vaccinating calves against pneumonia, a vet can undertake paired blood sampling (to determine rising antibody levels which suggest recent infection), nasal swabbing and histopathology of post-mortem material to determine cause.
The correct vaccination strategy that is active against the right bug at the right time, can then be chosen.
For example, if PI3 or RSV are identified in young calves, a fast-acting intranasal vaccine administered as early as possible in life may be appropriate to provide rapid immunity.
When pneumonia is occurring in older animals, injectables may be more appropriate.
Mr More says: “Vaccination will vastly reduce the subclinical and clinical effects of pneumonia. A 2% reduction in milk yield for the lifetime of the animal is highly likely [if an animal gets pneumonia], so it makes sense to opt for a vaccine for about £5.”
However, he stresses general vaccination is not ‘the panacea’ and must be combined with good environmental management to achieve the best possible results.
Results from 240 dairy farms which undertook an MSD Animal Health Calf Health Checklist (CHC), show calf management varies massively between units. As part of the CHC, a vet undertakes a full appraisal of calf rearing under five main sections: set goals and measure; good colostrum; good nutrition; low infection pressure; and healthy environment.
Each section is scored out of 20 based on various sub-categories. The higher the score the better.
Main areas for improvement identified by CHC
Measuring colostrum quality
Checking passive transfer of immunoglobulins
Improving feeding equipment hygiene
Diagnosing the cause of disease
Tracking daily liveweight gain
How to improve management
How to reduce environmental disease pressure
Do not mix age groups Newborn calves will have little protection against diseases shed by older animals. The less spread of ages in one air space, the better. Aim for a maximum age range of animals sharing the same air space of
Ensure good ventilation and drainage
Good ventilation is vital to remove moisture and heat and prevent build-up of pathogens which can cause disease. All moisture should also drain out of the building and away from calves, this will reduce humidity and disease challenge. Avoid draughts at calf level as this can create chill and lower immunity.
Clean it, clean it, clean it
Clean and disinfect pens between calves. When it comes to calf feeding equipment operate under the principle of – if you would not put it in your mouth do not use it
Visit the series home page for more information