| Buildings
Improve animal health through improved building environment
Ventilation guide outlines best practices to improve animal health and increase profits .
M aximising livestock performance is dependent on the synergistic relationship between animal welfare and animal health ,” explains agricultural specialist Stuart Daniell for fibre cement manufacturer Marley Eternit . “ Ventilation plays a huge role in making sure these components work together .”
To give beef , dairy , pig and youngstock producers the knowledge resource to provide optimum housing conditions for livestock buildings , Marley Eternit developed the “ Livestock building design and material guide for natural ventilation .”
Below , Stuart outlines a few best practices from the ventilation guide Stack effect “ For natural ventilation to occur , buildings must be designed for the stack effect to proficiently manage the air inlet and air outlet cycle ,” says Stuart . How the stack effect works
Air inlets draw in cool air which exits the building through air outlets as it begins to warm . If designed properly , this cycle keeps the internal building environment dry and fresh without becoming draughty . How to get air outlet
There is no ‘ one-size-fits-all ’ standard for air outlets , which can be obtained in multiple products and designs . Installing ridge sections is a good way to prevent rain ingress while enhancing the draw of air through the top of the building , explains Stuart . Unprotected open ridge section :
Unprotected open ridge sections deflect rain as air moves up the slope of the roof . This negative pressure also enhances the draw of air through the open vent .
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Protected open ridge section :
“ A protected open ridge has a covering to prevent rain ingress and can be built with a traditional fibre cement soffit strip or polycarbonate soffit strip ,” explains Stuart . “ Polycarbonate soffit strips allow more natural light into the building while avoiding hot spots caused by low level glass reinforced plastic .” Breathing and spaced roofs :
“ Air outlet can also be achieved by installing semi-compressed fibre cement profiled sheets as breathing or spaced roofs ,” says Stuart . When being used with the addition of open ridge sections , breathing roofs are a good solution for increasing air outlet capacity in buildings with high stocking rates . Spaced roofs also aid in air outlet while increasing natural light but make buildings unsuitable for anything other than housing adult cattle .
Air outlet calculations and in-depth information about different air outlet options can be found on page six of the guide . How to get air inlet
Managing airspeed is essential to maintain adequate air inlet without making livestock uncomfortable . While configuring air inlet for adult cattle can roughly be achieved with two evenly split sidewalls that are four times the size of the outlet area , greater consideration for airspeed is needed for youngstock and pigs . “ One of the biggest mistakes livestock producers can make when trying to prevent air draughts is to completely seal off a wall . This will put an end to the stack effect cycle and create a stale , stagnant environment ,” explains Stuart .
Find air inlet calculations and airspeed considerations on page seven of the guide . Roofing materials
“ Roofing materials are going to have a
significant impact on the long-term profitability and efficiency of a farm , so it is important to choose materials that have a positive impact on the entire production picture for decades to come ,” explains Stuart . “ Properties like humidity levels , sound reverberation , light control and temperature stability are key things to focus on .” Metal sheeting :
While metal sheeting may seem like the cheapest option up front , it can be very costly over time due to a short-lived life expectancy of 10 to 25 years in the damp UK climate .
“ Metal sheeting also has high thermal conductivity that can cause rapid temperature swings , and its inability to absorb moisture can also result in elevated humidity levels ,” says Stuart . “ This creates conditions that can compromise animal health .” Fibre cement profiled sheeting :
While being rot , rust and corrosion resistant , semi-compressed fibre cement has a life expectancy of at least 50 years . It is also capable of absorbing up to 25 percent of its own weight in moisture , greatly reducing humidity levels in buildings .
“ The low thermal conductivity properties of semi-compressed fibre cement help create a mild internal building environment year-round . It also absorbs sound , reducing rain reverberation ,” says Stuart . “ All of these properties lead to happy , healthy and more productive animals .”
To download the “ Livestock building design and material guide for natural ventilation ” e- book or to request a free hard copy , go to www . marleyeternit . co . uk / ventilation-guide
August 2018 | Farming Monthly | 35