Is your calf shed fit for purpose?
Calves that stay healthy in the first six weeks of life go on to produce more milk, according to Charles Chavasse of Zoetis.
Speaking at a recent Teagasc / Animal Health Ireland calf care event, he said: “What you do to calves in the first 60 days has a huge impact on how well you get paid in two years time. It’s absolutely essential that we look after calves and get them off to a good start.”
Focusing on the importance of housing, he said: “I’m not suggesting that everyone should go out and build a new calf shed. However, you can adapt what you have a lot of the time.
We need to make sure it works for the calf and the man trying to run the calf shed.
Chavasse, who spends most of his time advising farmers on how to get better functionality from their sheds, said there are five key areas that warrant consideration when it comes to the calf shed.
1. Fresh air
Continuing, he said: “The calf shed should deliver fresh air to animals, but there can’t be any draughts. Ideally, we would have fresh air entering a building and going straight through or out through and outlet in the roof. In doing that, it will move out noxious gases and pathogens.
“Fresh air is actually a disinfectant. If a virus is coughed up in a building, it will last for 20 hours. However, if the same virus is coughed up outside in fresh air, it will last for about 20 minutes. Air actually deactivates the virus and we need to make maximum use of fresh air in calf housing.”
Touching on how farmers can maximise the ventilation in their sheds, he said: “We need air coming in through the sides of the building.
“One of the problems we have in Ireland is that we hate to waste a wall. When building a new shed, farmers often place it beside an existing shed. The trouble there is that you haven’t got air coming in from both sides. If you have air coming on from both sides, the shed will ventilate properly.”
The inlet needs to be two-to-four times the area of the outlet and an outlet of 0.04m² is required per calf. In addition, Chavasse urged farmers to consider the material used to sheet down the side walls of sheds.
“I like seeing Yorkshire boarding on the sides of sheds; when the rain hits it, it bounces back out again.
“Yorkshire boarding consists of two rows of 6in boards, a 2in gap between the boards and a 2in gap between the two rows. It delivers fresh air, no rain and no drafts.”
When this boarding is used, and the outlet in the roof of the shed is of an adequate size, it will create a “suck effect” to draw any dust, pathogens and diseases out.
Although fresh air is necessary, Chavasse stressed that it shouldn’t result in the generation of draughts in the calf shed. A draught is a flow of air greater than 0.5m/second that gets in below the animal’s height. Ideally, he said, calf sheds should be sealed to a height of 4ft to prevent draughts from occurring.
3. Dry/good drainage
Farmers must also ensure that the lying area is dry and that the floor is constructed in such a manner that it allows urine and excess liquid to flow away, he said.
“There’s a reason why we want a calf shed dry. If it’s wet, bacteria and bugs will survive in that environment. I’d encourage you all to spend time kneeling in the back of your calf shed to see how wet it is.
“We have got to make it easier for liquid to leave the environment and that’s why it’s important to have a good, steep slope from the back of the pen to the front. Ideally, that should be 1:20 (for every 20ft, the floor drops by 1ft).”
On temperature, the Zoetis representative said: “Ideally, calves would like to be at a temperature 15-20° and that’s when they will thrive to their best.
“That’s difficult to achieve in Ireland, as calves don’t generate enough heat. The temperature inside of the calf shed is generally the same as it is outside and that’s the reality.”
Deep beds of straw are an effective way of protecting the young calf from the cold. They should be able to nest, so that their legs are covered by straw when lying down.
Breathable and washable jackets are also useful for a dry, newborn calf up to one month of age. However, care should be taken when cleaning these to prevent the possible spread of disease among calves.
5. Clean and cleanable
When calves are in the shed, he added, the use of water should be kept to a minimum. However, when the sheds are empty, deep cleaning with power washers, steam cleaners and appropriate disinfectants should be carried out as soon as possible afterwards.
Once cleaned and disinfected, a long rest period is an effective means of ensuring that bugs are eliminated from the calf house. In addition, easily-cleaned floors and walls are important to remove bugs from the building.