Pneumonia stops nearly 15pc of dairy heifers reaching their first lactation but vaccination, ventilation and warmth all make a difference
Shook! Shook as a bag of fertiliser. As I write this, I’m in recovery from what I presume is the flu. Sore all over, high temperature, harsh barking cough and a nose running like a leaky tap.
Or “the man flu” as my wife refers calls it. Sympathy is given, but only sparingly. It’s no great surprise that I picked up ‘the dose’ that’s going around. Two of our children got it, and sick kids coughing all over you is a sure fire way of getting ill yourself. Add to this the stress on the system.
We’re not busy yet with veterinary work but the management (and sadly financial) side of the business needed some serious attention. Give me lots of physical work any day. At least it clears the mind, and when you hit the bed that night, it’s lights out almost immediately.
Mental work is a lot harder — I end up lying wide awake thinking about some inconsequential problem. Throw in a terrible diet over the past two weeks and you have the perfect circumstances to allow a respiratory virus to take hold.
I got the flu vaccine last month, but how can I expect it to work if I’m not taking care of the body and the mind? First world problems I suppose. Anyway, I’m on the mend, but
as I finished a bout of trying to cough up a lung, I started to compare my particular scenario to that which many young calves will experience over the next few weeks.
Here’s a chilling statistic for you: calf pneumonia is the biggest known cause of death in calves between one month and one year of age. And nearly 15pc of live-born dairy heifers fail to reach their first lactation as a direct result of getting pneumonia as a calf.
So if you have 30 Friesian heifer calves on the ground by early April, you can, on average, write off 4-5 of them ever getting to the milking parlour due to pneumonia alone. I’d say that woken a few readers up: “Never mind the vet and his case of man flu, I’m down five heifer calves and I’ve barely started calving.”
OK, so what can we do to minimise the risk? Vaccination is the easiest piece of the jigsaw to fit. There is now an intra-nasal vaccine that has a licence to be given to calves on the day of birth. At least three litres of good-quality colostrum, treat the navel, whack in two tags and vaccinate the calf up the nose. Job done.
The old Irish saying ‘Tus maith leath na hoibre’ (a good start is half the work) is apt.
However, vaccination is only as good as the environment it’s in. Let’s presume we have good colostrum management nailed down at this stage. The vaccine has been given. What happens next?
Well, what should happen is that the calf goes to a separate calf house, knee-deep in fresh straw, away from every other animal in the shed. Unfortunately, this doesn’t always happen.
A lot of calf-rearing facilities I see are in parts of sheds that have been converted. Take one I was in last week. It was a model for hygiene and comfort. However, throwing a critical eye on the set-up, the major flaw was apparent: the baby calves were only about 10 feet away from the cow cubicles.
Cows emit an enormous amount of heat. In the cubicle shed, air movement is dictated by the ‘stack effect’. The heat generated by the cows forces air upwards towards the roof outlets, creating a current that sucks fresh air in from the inlets.
However, this doesn’t happen with calves. They don’t emit heat in sufficient quantities to force air to move.
So, with cows on one side of the shed and calves on the other, some of the air over the cows will move towards the calves. Cows at this time of year are under stress and, by default, will be shedding respiratory viruses in their breath. These virus-laden micro-droplets will be over in the calf shed in a matter of minutes, being inhaled by the newly born calf.
The calf may be vaccinated, but like me with the flu vaccine, the jab is only as good as the patient it’s given to and the environment the patient is living in.
So we have calves in a shed that are sharing air-space with cows (or worse again, weanlings). We aren’t going to manage to build a new shed this spring, so what can we do?
We can try to change air movement by opening up outlets and inlets. Get someone with a bit of expertise to look at your shed. A few quick figures – there should be 0.1m2 of outlet per animal in the shed. So 100 animals need 10m2 of an outlet.
The inlet area should then be twice the size of the outlet. This can easily be achieved by simply lifting a few sheets. A simple solution to a complex problem.
Chances are, if your calves are sharing a shed with cows/weanlings, it’s a big open shed. So we need to focus on keeping calves warm.
Deep straw is key. I hear one particular wise vet regularly saying, “there’s a lot of calf problems that can be easily solved by just adding more straw”. Bed them down well, daily — they’ll thank you for it.
Calf jackets are a product I’ve seen a lot written about of late, with some questioning their benefits. I can only attest to what I see on the ground: if the housing isn’t right (as in the shed is too open or too high), then calf jackets are the difference between life and death, particularly in calves that have low body fat cover (our little Jersey friends spring to mind).
Good jackets cost around €30. It’s a no-brainer when you consider the value of a heifer calf, or even a beef bull calf. Spend a little to save a lot.
For those of you concerned with my well-being, I’ll survive. Take steps now to make sure that your calves do too.
Eamon O’Connell is a vet with Summerhill Vet Clinic, Nenagh, Co Tipperary