Farmers get some expert advice on ventilating livestock buildings
Members of the Rural and Industrial Design and Building Association (RIDBA) hear how they can help farmers optimise livestock buildings
Concern has been expressed about the extent to which farmers understand the importance and value of providing adequate and appropriate ventilation in livestock buildings.
It was mooted to more than 50 members of the Rural and Industrial Design and Building Association (RIDBA), most of whom are agricultural building contractors, by Jim Loynes, former ADAS buildings design specialist and now assistant head of engineering at Harper Adams University College.
Mr Loynes, BSc (Hons), CEng, MIAgrE, was talking about the natural ventilation of livestock housing to RIDBA’s quarterly council meeting, held at Patshull Park Hotel, Golf and Country Club in Pattingham, in the college’s home county of Shropshire, on July 4th.
In his presentation Mr Loynes said that a “general purpose” building was invariably what a farmer paid for when what he really required could only be provided by good design.
He said the design process needed to start by calculating the outlet area at the ridge of a building (the gap required to allow stale air out) and then considering how this area can be replicated at the inlet (openings below the eaves to allow fresh air in).
The size of the inlet gaps or open ridge needed to be based on the building’s dimensions and expected stocking densities, with a main concern being that rain could enter the building through an open ridge. However, this had been solved with the development of a protected open ridge.
“The open ridge and protected open ridge have both been available for some time now. However, either farmers don’t know about the benefits of good ventilation or don’t want to pay for an open ridge or protected open ridge to be installed. Or is it a question of ease of installation?” he asked the RIDBA members.
In his opinion, alternatives to the open and protected open ridges, such as “crown-cranked” or “two-piece” ridges, did not provide adequate outlet area for most livestock housing densities even though sufficient inlet area could be formed using spaced (often referred to as Yorkshire) boarding.
Suppliers such as RIDBA members needed to know exactly how the farmer intended to use the building and what animals he intended to house in it (in terms of numbers, breed, housing period, feeding, bedding, slurry system and so on), and perhaps more importantly, which QA scheme (such as Red Tractor) the farmer aimed to satisfy.
“Unless you know exactly this, in my opinion there is no way you can provide a building with even adequate natural ventilation openings in it,” said Mr Loynes.
“Furthermore, when considering stock housing, a general purpose building, which is one the purchaser can adapt to meet his needs, will not satisfy the needs of the stock. Over-design may be a better solution as it is easier to close up a building than to open it up to ventilation.”
A well-designed ventilation system (natural or mechanical) helped to remove dust, excess moisture and bacteria from a livestock building while providing a minimum air flow rate and a draught-free lying area for stock.
He referred to RIDBA’s Farm Buildings Handbook which includes an updated version of the SFBIU’s design guide which caters for larger livestock, and is available to farmers through www.ridba.org.uk.
Farmers requiring more advice about ventilating their livestock buildings can contact Mr Loynes on or RIDBA on .