Don't overlook the importance of building ventilation

Don’t overlook the importance of building ventilation 

Slower growth rates, health problems, reduced milk yields and poor mobility are just some of the issues caused by inadequate building ventilation that could be hindering your livestock’s performance. 

“The impacts of poor building ventilation often manifest themselves indirectly in livestock,” explains livestock specialist and Honorary Research Fellow at the University of Aberdeen, Jamie Robertson. “As a result, the issue of ventilation can be fairly low down on producer’s list of priorities.” 

Natural ventilation works on the principle that when the wind speeds drop, warm, stale air will rise to the top of a building, where it should be able to escape and then be replaced by the same volume of fresh air drawn in from the sides. 

“This is called the ‘stack effect’ and with enough outlets provided in the roof and enough inlets provided on the sides of building, this system will help keep the building adequately ventilated without any further intervention,” says Jamie.  
“Farmers are often surprised by how big an outlet – usually provided by an open space in the roof ridge – is required to maintain good ventilation levels.” 

“It seems that more farmers are understanding how important it is to have fresh, airy livestock buildings and are putting up larger sheds with plenty of gaps between side panels,” continues Jamie. “Many believe that this is all they need to do to maintain a healthy environment for their livestock, but unfortunately this is far from the case.”


“The best way to open up the top of a livestock buildings and help ensure adequate levels of ventilation is to install an open ridge with upstands on either side,” explains Jamie. “Not only does the open ridge provide a calculated outlet space within a building, but the upstands help to prevent most of the rain from getting inside the livestock housing.”  

We produce a range of covered open ridges, which suspend a strip of material between the upstands to completely block out the rain. Our new natural light system, using a clear GRP soffit strip, helps to keep out the rain whilst also allowing high levels of natural light to pass into the building. 

“The added advantage of using upstands is that when wind - and remember that wind is driving ventilation more than 80% of the time - runs over them, negative pressure is created. This results in air being actively sucked out of the upstand ‘chimney’ and therefore out of a building,” Jamie explains. 

This chimney effect is especially useful in calf housing when the lower levels of heat generated by youngstock are not sufficient to drive stale air up and out of a building via the stack effect

An avoidable cost

It is estimated that 50% of cattle buildings in the UK are not adequately ventilated, seriously hampering livestock performance. 

“Moist, stale air is a perfect breeding ground for bacteria,” continues Jamie. “Poorly ventilated livestock buildings can therefore lead to a variety of health issues in cattle, such as pneumonia, with a negative impact on growth rates and milk production.” 

“Recent research coming out of Northern Ireland indicates that if a calf is treated more than once to combat respiratory disease during its initial milk feeding phase, the total cost to a farmer can be as high as 1,000 Euro [about £880] per the lifetime of that animal due to slower growth rates, later bulling time, delayed first calving and reduced milk yields in first and second lactations,” Jamie states. “Avoiding such set backs are obviously a key priority for any farmer.”

Moving in the right direction 

“I do find it promising that more and more farmers seem to understand that something needs to be done to help improve the air quality within their livestock buildings,” concludes Jamie. “What we need to do now is make sure that they are properly informed so that they make the right decisions and make the right changes to their livestock buildings to help achieve the best levels of ventilation possible.” 

To hear more from Jamie Robertson on ventilation, please visit the Marley website:

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