How to defeat a calf killer
Pneumonia is the second biggest cause of calf mortality, but proper housing and early diagnosis can go a long towards beating the disease, writes Tommy Heffernan
WE know more than ever about the causes, symptoms and treatments of pneumonia in calves. So why, after scour, does it continue to be the second biggest cause of calf mortality on our farms ?
There are no easy answers or magic solutions.
In my opinion, pneumonia continues to be an issue because too often we don’t deal with all the contributing factors.
Also in a future where our choices of antibiotics will inevitably be more limited we must look at management at reducing risk and focus very much on prevention.
So what drops the immunity of calves to make them more susceptible? ÷Not enough( less than 3litres), poor quality or timing (after six hours) of colostrum leaving natural immunity low ÷Under-nutrition for prolonged periods ÷Poor housing prolonged cold leading to dropped immunity levels. ÷Calf scour or other diseases reduce immunity. ÷Calves left outdoors during extreme changes in weather.
And the following factors increase the exposure of viruses and bacteria that cause pneumonia in our calves? ÷Calves sharing airspace with older animals who may be shedding viruses to more vulnerable young calves. ÷Overcrowding causes stress which lowers immunity and also allows close contact between animals to spread disease ÷Poor housing ventilation(too much/too little) can play a huge role in contributing to pneumonia. ÷Any sort of stress particularly for long periods releases cortisol which lowers immunity and inhibits the body’s ability to fight off disease.
So when dealing with calf pneumonia we must identi- fy and address all these risk factors.
We also need to recognise the symptoms, because the earlier we identify and treat the disease the better the outcome.
Once damaged, the lungs don’t heal and even when calves don’t die they can have long term damage stopping them performing and growing. ÷The primary symptoms are: ÷Dullness ÷Off form ÷Temps over 40C ÷Poor appetites ÷Increased breathing rates ÷Nasal discharges and coughing
There are a number of viruses that affect calves — RSV Pi3 is the big one in young calves followed by IBR and coronavirus.
There are also a number of bacteria such as mannhaemia, pasteurella, histophillus and mycoplasma.
Calves can get viral infections on their own, or worse, in combination with bacteria. Calves can also get bacterial infections on their own.
ANTIBIOTICS
Antibiotics will only treat bacterial infections. The key to treatment is correct antibiotic given early and for long enough. Talk to your vet when choosing antibiotics and individual calf treatments.
In all cases of pneumonia, anti-inflammatories are very beneficial especially when given early.
One of the things I often do is when calves have died from pneumonia is a full post mortem. There is nothing more transparent about how severe the disease is than when you see the damage done to lungs following an infection.
Making an early diagnosis can make a real difference’. This means doing tests to find out what bacteria or viruses are causing the problem.
The best options here are usually nasal swabs of fresh cases or full post mortem on dead calves sampling damaged tissue.
An accurate diagnosis allows more strategic control through a vaccination plan that should be drawn up with your vet.
In some cases, getting calves out early can be beneficial when trying to reduce the risk of pneumonia.
If calves are outside ensure they have shelter and are only turned out during settled weather. Calves should never be turned out in unsettled weather because it will cause stress and lower the immunity and increase their risk of pneumonia.
HOUSING AND VENTILATION
Proper housing plays a big role in preventing pneumonia. Unfortunately for many years we housed and treated calves like small cows!
A calf is very different to a cow in its needs particularly our dairy calves with poor fat covers. They need to be kept warm.
This is complicated by the fact we need fresh air to kill bugs and reduce pneumonia. Calves spend up to 20 hours a day lying down. Fresh air must be in all the shed right down at calf level.
Ammonia and other noxious gases can irritate the airways of calves. You can’t beat fresh air in the right quantities.
Air moving too fast is a draft and this if prolonged lowers the temperatures of calves. Below 10 degrees a calf must work hard to stay warm. If this is prolonged or not fuelled by extra feeding, the calf ’s immunity will drop.
Extremes of heat or cold are breeding grounds for viruses and bacteria in calves.
The easiest way to keep calves warm is by providing plenty of straw for nesting. Fresh air is harder to regulate because the weather can change day to day or even hour to hour.
This is why calf hutches work well — the calf can go into the hutch for warmth and out in fresh air as required. The calves regulate their own environment and they also are in smaller groups with less sharing of airspace.
Te best calf sheds are igloos which are contained under a roof just for shelter.
A very good alternative especially in open sheds, is the calf jacket.
Remember too that if calf pens are beside or in contact with adult dairy cows that presents a huge disease risk for dairy calves. Calf pens should have a separate airspace to adult cows.
Your dairy calves are the future of your farm. If you give them the comfort and space they require, they will more than repay your investment.