Agriland caught up with Teagasc farm buildings and infrastructure specialist, Tom Fallon to see what the ideal calf shed entails.

With spring calving kicking off, Fallon provided some advice for farmers on the best practices in terms of ventilation, drainage, space, and lighting to ensure the calf is comfortable and able to thrive.

The farm buildings and infrastructure specialist demonstrated the best practices using the calf shed based on Teagasc's Kildalton Agricultural College; however, he said mistakes were made even here and the shed itself is not perfect.

Ventilation

Young calves have a limited immunity, therefore ventilation is one of the most important aspects of a good calf shed needed to ensure stock can thrive.

Good ventilation significantly reduces the risk of pneumonia, as well as reducing the risk of other diseases and issues by pushing out airborne bacteria, gases, dust, and stagnant air.

Fallon did however highlight that advancements in ventilation has caused calf houses to do a 360° turn, going from cosy in early spring and stuffy towards the end of the season in older sheds, to cooler in early spring and comfortable throughout the season in newer sheds.

He said new sheds are perfect from after Valentine's week, however finding the balance to prevent chill in early spring can be difficult.

Fallon noted how 10℃ is the minimum temperature needed for dairy calves to thrive; any lower and they begin burning energy reserves to stay warm.

Herds calving down in early February can easily manage those two weeks through calf jackets, extra bedding, and heat lamps, but winter calving herds may need to rethink their design if the shed is going to be cool for the season.

He personally feels Yorkshire boards are the best method of providing inlet ventilation, saying they baffle the air speed and eliminate draughts if done right.

However, other methods such as vented sheeting can have varied performance, he said. If the vents are too big they may let in too much rain, or if they are not enough big enough, air flow may be restricted.

Fallon advised that the the Yorkshire boarding ideally should be comprised of 75mm boards, with 25mm gaps between each, and a 25mm gap between the two lines of boards, subject to achieving 0.08m² of inlet area per calf.

Fallon also reminded farmers that long, narrow sheds are easier ventilated than wide, square sheds.

He said the ideal eave height is about 3.6m, as calves do not generate enough heat to shift a big volume of air above them (to get a good 'stack' effect.)

Problems with ventilation begin in areas such as;

Inadequate roof pitch (less than 15°);
Excessively high eves (over 4m);
Poorly spaced Yorkshire boarding;
Excessively wide building (wider than 11m);
Obstructed inlets/outlets;
Poorly designed ridging.

Calf shed

Once the shed is well ventilated, the next step is ensuring it is well drained so calves have a warm, dry bed to lie on. This is crucial as calves can spend up to 80% of their time lying down.

Fallon recommended having a fall of 1.20 in the flooring, as this ratio would let effluent drain away quickly into waste channels, which will carry any run-off out of shed to an external storage point.

He also reminded farmers that if urine seeps into cracks in the concrete, it will come back as ammonia which can lead to bovine respiratory disease (BRD).

The specialist reminded farmers to regularly carry out the 'knee test' in the bedding areas; if their knees are wet when they get up the calf is also lying in damp conditions, which will in turn lead to a drop in the calf’s temperature.

Fallon said there should be a minimum of 2m², preferably 2.3m² per calf in each pen, saying they clearly perform better with more space.

In the Kildalton calf shed, stock boards have been installed on pen divisions to reduce disease transfer, as well as to reduce air movement and act as shelter for the new-born calves.

Fallon also highlighted the importance of natural lighting, saying the UV from natural lighting acts as a disinfectant so 15% of the roof should ideally be clear sheeting.

However, if natural lighting is limited and farmers are relying on artificial lighting, they should have at least 50 lux.

He also reminded farmers of the importance of having clean fresh water available to calves at all times, and feeders for roughage and concentrates.