| Buildings
When choosing building materials for livestock housing , Marley Eternit fibre cement is the best option due to its ability to absorb up to 25 percent of its weight in moisture – greatly reducing humidity and condensation .
Reduce livestock health risks with the right housed
Ventilation guide outlines best materials and design requirements for livestock buildings environment
H ousing conditions are a major factor in controlling multifactorial respiratory diseases , says livestock health specialist and honorary research fellow at the University of Aberdeen Jamie Robertson . This drives the need for livestock producers to make ventilation , drafts , air quality and humidity management key aspects in their disease prevention programme .
While preventative practices for respiratory diseases like pneumonia are essential for herd animal welfare , they also carry a significant financial safeguard .
According to research from Scarsdale Farm Vets , the average dairy calf with pneumonia leads to costs of £ 43.26 and the average beef calf costs £ 82.10 – with significantly lower growth rates and increased treatment medicine use contributing the greatest costs .
Recently , fibre cement manufacturer company Marley Eternit developed the “ Livestock building design and material guide for natural ventilation ” to outline best ventilation practices for increased livestock performance and decreased disease risks .
Available as an e-book or hardcopy , this detailed guide outlines recommendations from industry experts and leading research for beef , dairy , pig and youngstock buildings . In the guide , readers can find : Natural ventilation design requirements
To keep adequate airflow in livestock buildings , Robertson recommends farm buildings have a roof pitch of 15 ° to 22 °. Steeper angles create a chimney effect to draw out excess heat , moisture and stale air from buildings . This airflow system , better known as the stack effect , requires management of wind impact and the physics of the air inlet / air outlet cycle .
“ Buildings for animals need a hole in the roof to let the hot air , stale air , moisture , bugs and all the other excesses out ,” notes Robertson . “ If you don ’ t have a big enough hole in the roof , then you accumulate heat and moisture inside the building .”
Youngstock up to 100kg need 0.04m2 air outlet space per animal , increasing to 0.10m2 outlet space per adult animal . Design for air inlet should consist of two evenly split sidewalls that are four times the size of the outlet area to maintain air flow throughout the building while reducing airspeed at animal height . Air outlet products
There are multiple options when it comes to design and products for air outlet . Marley Eternit has both protected and unprotected open ridge upstands which prevent rain ingress while enhancing the draw of air through the open vent . To provide buildings with more natural light while preventing hot spots caused by low level grass reinforced plastic , Marley Eternit protected open ridges are built with a polycarbonate soffit strip .
“ To achieve air outlet in buildings for adult cattle , fibre cement roof sheets can also be installed as breathing roofs or spaced roofs ,” says Lorna Woolly , area sales manager for Marley Eternit . “ Breathing roofs are made by inserting a 15-25mm timber batten between the profiled sheets at the horizontal overlap of each course . This helps minimise rain ingress .”
Spaced roofs should be fitted with a space around 10mm between each adjacent sheet and is best achieved with Profile 6 roof sheets trimmed to a width of 1,000mm .
Material recommendations
Building materials contribute significantly to the shed environment , with semi compressed fibre cement profiled sheeting serving as the best roof material due to its ability to absorb up to 25 % of its dry weight in moisture .
According to Woolley , the moisture absorption ability of fibre cement can make the difference between a low humidity shed environment and high humidity shed environment .
“ Fibre cement absorbs excess moisture , soaking up any condensation into its surface to be dissipated once conditions are right ,” says Woolley . “ When this is combined with proper building design for the right roof slope and ridge construction for air flow , fibre cement profiled sheeting can contribute to decreasing the potential for costly and long-term healthrelated issues such as pneumonia .”
Fibre cement roofing also helps maintain a more stable shed temperature , adds Robertson , due to its insulation reducing solar gain , while metal roofing ’ s lack of insulation can lead to severer temperature fluctuations . This is especially important to youngstock producers . “ Until two to three months of age , young cattle are not very good at regulating their body temperature and are very sensitive to varying temperatures within a short period ,” explains Robertson . “ So mineral fibre is better than tin in those situations because it doesn ’ t exaggerate solar gain .”
To download the ventilation guide online or to order a hardcopy , go to www . marleyeternit . co . uk / agri-ventilation-ebook .
30 | Farming Monthly | June 2018 www . farmingmonthly . co . uk