Managing in the heat
Cool season preparation
Shade options
In hot weather, cattle actively seek shade, which reduces the radiant heat load by 50% or more. There are three options:
- Natural shade from trees.
- Portable paddock shade structures.
- Permanent shade shed.
Option 1: Natural shade from trees
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Pluses
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Minuses
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The cheapest method of providing shade.
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Difficult to provide adequate shade every day during paddock rotation. Position and number of trees in each paddock, and walking distance from dairy are critical.
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Climate friendly, as trees absorb CO2, and doesn’t require any electricity to establish or operate.
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Trees along laneways are a risk to management if cyclones or severe wind storms are a possibility.
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Enhances local biodiversity.
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Takes many years to establish.
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Increased risk of mastitis in wet, hot weather, especially in cows around calving time.
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Recommendations:
- Establish tree lines on the northern and western edges of pastures so shade is accessible during hot afternoon hours.
- Aim for 4m2 of shade per cow at midday.
- Fence outside the perimeter of the trees root systems to protect them from cow treading which may compact soil and kill them.
- Fencing trees so cows do not lie down in mud and dung will also reduce the high risk of mastitis around calving time (this risk is greater if cows’ teat health and teat end condition are poor) (see Countdown Farm Guidelines 1 and 9).
- Ensure feed and drinking water are provided close to trees to encourage cow intakes.
- Use deciduous trees along laneways so they remain drier in winter.
- Fence edges of wide laneways where cows walk long distances in summer.
- Develop a comprehensive farm plan that incorporates significant tree plantings over time. Be sure to select tree species well suited to your area and the location of your farm. Seek recommendations from an advisor (e.g. Greening Australia, Your Regional NRM Body (CMA, DPI or LandCare).
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The best time to plant trees was 20 years ago. The next best time is now!
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Continued use of tree lines like this without fences to protect the
trees’ roots will ultimately lead to dead trees from soil compaction.
Option 2: Portable, low-cost paddock shade structures
When not enough natural paddock shade is available, artificial shade can be used to protect animals with shelter from solar radiation using portable paddock shade structures or a permanent shade shed.
Portable paddock shade structures may incorporate shade cloth or corrugated iron roofing. Shade cloth is cheap, but it offers less protection than solid roofing. Wheels or skids can enable them to be towed behind a tractor or ATV.
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Pluses
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Minuses
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Enables you to bring the shade to the cows vs the cows to the shade.
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May need several structures to provide sufficient shade for all animals.
Best suited to smaller herds.
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Can be readily moved with the animals, or moved to cleaner, drier locations close to feed and water when necessary.
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Shorter useful life than a permanent shade structure.
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Payback period to recover construction costs through increased summer milk yields may be shorter than expected.
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Are vulnerable to high winds.
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Recommendations:
- Ensure shelters are high enough so that heat is not reflected from under the roof back down onto the cows.
- If using shade cloth, install it properly under tension, so it is not buffeted by winds. If so, it should last five years or more. Use shade cloth that blocks at least 80% of sunlight.
- Re-locate structures if dung builds up and/or the ground underneath becomes muddy to reduce the high risk of mastitis around calving time (this risk is greater if cows’ teat health and teat end condition are poor) (See Countdown Farm Guidelines 1 and 9. Visit www.countdown.org.au).
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Shade structures on wheels or skids are easily moved around the farm.
Shade encourages cows to eat (and produce more milk).
Option 3: Permanent shade shed
A permanent shade structure (shed) is the third option.
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Pluses
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Minuses
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Quick to set up.
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Location on farm not always ideal for paddock rotation.
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Doubles as a feed-out facility.
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Most costly means to provide shade. Cost depends on amount of concrete needed, and the cost of roofing, support structures and effluent management system.
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Can use to also provide active cooling if desired (sprinklers and fans).
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Must have an effective system for handling effluent and run-off.
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Benefit / cost ratio based on expected increase in milk production, milk composition and fertility is about 2-3 : 1 for a well made structure.
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Need to comply with regulatory approval processes.
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Long useful life (at least 25 years).
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Recommendations:
- Roofing - material, height, vent area, slope
Aluminuim, white or galvanised iron is preferable. Roof height should be at least 3.7m at its lowest point. Ensure good air movement is created through the shed via 'stack effect', by providing a vent at the top coverng 10% of the total roof area, with a roof slope of at least 15 degrees (ideally 30 degrees)
- Flooring - material, slope, effluent system
Concrete floors are the best, with minimum slope of 1:500, maximum slope of 1:20, allowing for a flush cleaning system that runs into an effective system for handling solid and liquid effluent. Well-compared clay is better than coarse gravel, particularly once a manure/organice mat forms. Whatever the surface, it needs to be scraped or raked clean regularly.
- Feed and water troughs
If shed is east-west oriented, position feed and water troughs on the southern and northern sides.
If shed is north-south oriented, position feed and water troughs on the eastern and western sides to reduce walking to water and preferably position feed troughs under shadeEast-west shed - position feed and water troughs on the southern and northern sides. North-south shed - position feed and water troughs on the eastern and western sides to reduce walking to water and preferably position feed troughs under shade
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When designing a shade shed, it is important to also consider whether the shed is best orientated eastwest
or north-south, and winter and summer sunshine angles.
When designing and building a shade shed,
there are many details to consider, so get professional advice.
