Excessive heat load in livestock can result in significant production losses, animal welfare problems, and even deaths in extreme conditions. Shade structures are one effective way to reduce the impact of heat on your cattle, lowering exposure to solar radiation. In this article, we share our advice for feedlot design and construction and draw on the best practices from the Australian Lot Feeders Association (ALFA). We’ve included the key considerations you should make, including site location, drainage, climate, orientation, and more. Considerations for a feedlot shelter or feedlot shed The design objectives for a shade structure or feedlot are to provide adequate shade to improve the well-being of your livestock. Other key priorities include maximising airflow, improving pen drying, and minimising obstructions during cleaning. During the planning process, remember the key factors outlined below. Mandatory requirements As laid out in the Australian Animal Welfare Standards and Guidelines for Cattle (DAFF, 2013), you must follow certain mandatory requirements. Firstly, you must conduct a risk assessment annually, assessing the heat load risk at the feedlot and implementing appropriate actions to manage this. Secondly, you must have a documented Excessive Heat Load Action Plan and implement appropriate measures in a heat load emergency. Shade per animal In Australian conditions, shade structures should provide more than 2m2 of shaded pen floor space per animal. This guideline recognises that spreading animals out is beneficial in excessive heat load events. Even in normal summer conditions, overcrowding will limit any potential production benefit. Stock density must account for age, size, behaviour, movement, and feeding patterns. Humidity and ventilation Moisture control plays a critical role in maintaining healthy stock on a covered feedlot. High humidity will impact your herd’s health, considerably increasing the spread of bacteria and disease. Higher humidity also contributes to the faster deterioration of your building infrastructure and equipment. Natural convection and wind are the two main forms of natural ventilation to remove excess moisture from your feedlot. The effectiveness of ventilation is heavily dependent on building design, including building width, height at the eaves, height of roof peak, angle of roof and provision, and the ridge gap. When designed correctly, these features promote airflow by impacting wind pressure across the roof and thermal buoyancy. When the heat rises inside the feedlot, it rises and escapes through the roof vent, allowing fresh air to enter through the open sides. Location and planning requirements for a cattle feedlot In most Australian states, feedlots above a particular size require approval. These are outlined on pages 15 and 18 of the MLA Feedlot covered housing systems manual. Rainfall zones can also influence the type of shade you need. For example, in a high rainfall area, a north-south orientation with a retractable shade cloth allows for optimum pen drying. If you opt for a solid structure with a permanent roof, you need sufficient drainage to avoid ponding on the pen surface. Site selection Good site selection is critical for the economic, environmental, and management performance of a covered housing system in cattle feedlots. It affects natural ventilation, approval processes, capital and operating costs, and building functionality. Key factors include proximity to accessways, sales yards, and services as well as labour and feed availability. You’ll also need to consider accessibility, availability of materials and resources, groundwater and surface water protection, heritage, ecological, and risk assessments. Feedlot orientation The best feedlot orientation depends on the structural design, local climate, and prevailing winds. The longitudinal row shade structure should run north to south, especially if it has no strips for pen drying. With the shade material orientated east-to-west, you can elevate the eastern side of the structure to a 10-15º pitch, encouraging floor drying in the morning. During the afternoon, this provides more shade and increases airflow under the structure. For a compacted clay or gravel floor, a north-to-south orientation works well because the sun strikes every part of the pen floor at some point during the day. Water supply Water supply is required for stock drinking, feed processing, cleaning, and general operations. Water reticulation systems can be either gravity flow, pressurised, or a combination of both. We recommend seeking professional assistance to determine a system layout, pumping capacity, pressure, pipeline sizes, and valve locations. Height Minimum eave height depends on ventilation requirements and the height of machinery operating inside, such as pen cleaning equipment. For reference, the fixed height of equipment typically ranges from 3 to 3.5 metres, with a full lift height up to 5.25 metres. A minimum clearance of at least 600mm is recommended on the underside of overhead structural elements, such as beams, trusses, and roof sheets. Drainage Roof runoff can either be collected in gutters or freefall off the roof and collected in a surface drainage system. Advice on this aspect should be sought from relevant regulatory authorities during the design process as the regulatory requirements vary from state to state. Common drainage systems include gutters with downpipes, gutters without downpipes, and ground-level drains. Shading material Most Australian feedlots use corrugated galvanised iron, ZINCALUME®, or COLORBOND®. Waterproof fabric is also used to cover hoop structures, though these may not offer the same durability or longevity. ZINCALUME® steel cladding consists of aluminium, zinc, and magnesium, combining the aluminium’s corrosion protection with the sacrificial protection of zinc. This offers durability, environmental benefits, and affordability. COLORBOND® cladding is pre-painted steel with a ZINCALUME® core coated in a baked-on corrosion inhibitor. This makes it more durable and suitable for highly corrosive environments, along with its signature five layers of protection. The roof colour influences a feedlot’s heat transfer, including solar absorptance and solar reflectance. Generally, lighter colours absorb less heat than dark colours and highly reflective materials like Zincalume® are superior at reflecting solar radiation. Farm sheds and feedlot shade structures If you want to increase farm productivity and herd health, investing in a yard cover is the most impactful step you can take. At ABC Sheds, our experienced team has the expertise and know-how to design a shed that’s tailored to your needs. To see your options, try our virtual shed designer or download our farm sheds brochure today.
Feedlots — Design and planning tips from professionals
Excessive heat load in livestock can result in significant production losses, animal welfare ...
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