Caring for livestock during a heatwave

Livestock owners should take special care of their stock during a heatwave as animals suffer from the heat as well.

Sheep and cattle

Extreme heat can have a detrimental effect on animal health and wellbeing, but there are precautions that you can take to reduce this including:

  • providing plenty of shade and shelter
  • providing cool water close to the shade – animals drink up to double the amount of water in hot weather
  • keep troughs clean especially when moving stock into a new paddock
  • if possible, don't let animals access dams as they can become boggy and animals accessing the water may get stuck
  • check on livestock daily
  • look for signs of heat stress such as sweating, panting, and drooling
  • minimise stock movement and if they need to be moved do it during the night or the coolest part of the day
  • transporters of livestock should also have in place contingency plans to handle unexpected breakdowns, especially during hot weather.

If you are not living at a property, arrange for a neighbour to check on animals in your absence.

Poultry

Poultry are vulnerable during heatwaves. Large losses can occur, particularly in the South Australian summer.

The most important factor to cool birds down is ventilation (for example: wind, fans).

If temperatures are above 30°C, it is recommended that birds are provided:

  • large areas of shade and shelter – enough adequate space for each bird
  • ventilation from fans, with back-up power supplies or alternative ventilation systems
  • cool water from foggers or sprinklers – these are less effective if humidity reaches 80%
  • cool drinking water.

Management considerations

  • Young birds carry less fat and have a higher heat wave tolerance.
  • Early heat waves are the worst because of a lack of bird acclimatisation.
  • The length of a heatwave and height of night temperature are significant factors in stock and production losses.
  • Late afternoon losses occur because of direct sunlight on birds.
  • Higher density rations may be needed because of appetite loss. Lights in the cool periods of the day encourage eating and drinking.
  • In-shed heat production is dependent on stocking density.
  • Water consumption doubles when temperature rises from 21°C to 33°C.  Warm water is rejected by heat affected birds, hence water cooling by continuous running or the use of ice is important.
  • Vitamins A, D3 and E may aid in heat wave stress reduction.

Heatwave preparation

  • Be ready for heat waves at the start of October.
  • Check water supplies, cooling equipment and waterers.
  • If necessary, repaint roofs.
  • Slash weeds around sheds.
  • Remove accumulated manure.
  • Clean wire to ensure maximum air flow.
  • Check and clean thermometers. Management should be based upon bird condition rather than absolute temperature.
  • Consider nutrient density of the ration.

Poultry house design

  • Roof reflection – a double coat of the following mixture applied to the roof will reduce the in-house temperature by up to 5°C:
    • 9 kg hydrated lime
    • 0.5 litre PVA emulsion
    • 20 Iitres water
  • Insulation – this is extremely useful in reducing radiant heat.
  • Ventilation – sheds should be constructed with ventilation principles in mind (greater width in the gable). Bad environmental conditions can be overcome by using evaporative coolers.
  • Walls – the late afternoon sun on galvanised walls magnifies heat stress on that side of the shed. This can be overcome only by changing design.
  • Flaps or shutters have the advantage of excluding direct sun but allowing unrestricted air movement.

Heatwave action

Restraint in the use of cooling equipment at the start of summer may be practised with discretion to allow the birds to become acclimatised. The following should be the daily routine during heat waves.

  • Start the day early. Be forewarned by weather forecasts.
  • Open ventilation areas except where birds will be exposed to direct sunlight.
  • Check water lines and drinkers to ensure adequate water supplies.
  • Collect eggs early to avoid soiling from foggers.
  • Roof spray to reduce radiant heat increases as the sun rises in the sky.
  • Use foggers when the temperature reaches 33°C. Observation of birds (panting) is the best guide for the initiation of this treatment.
  • Keep water cool.
  • Move cautiously through the shed to avoid further stress.
  • Ensure late afternoon care.
  • Remove all dead birds after the crisis.
  • Move lighting patterns to give extra lighting in the cooler periods of the day, enabling birds to feed when cooler.
  • Check all equipment in case it is needed the next day.

Equipment

  • Roof sprays – these help reduce heat build-up in sheds. The water can be recirculated or run off the roof to give an evaporative cooling effect.
  • Foggers – sharp temperature drops in a short period can be achieved using foggers (with low pressure systems, limit their use to 30 seconds at a time to avoid undesirable feather wetting).
  • Horizontal fans – these can be used to circulate cool air and remove body heat. Fogging nipples mounted on the front aid evaporative cooling.
  • Medication tanks – these can be used for water storage or as a supply point for cooling water by using crushed ice in them.
  • Water supply – direct exposure of water lines to the sun results in warm, unpalatable water. Deep burial of pipes on the southern walls helps keep water cool.
  • Filters – where dam or borewater is used, these are a sound investment to prevent clogging.
  • Evaporative coolers – these give excellent air movement and remove the need to constantly attend the birds. Consideration must be made of shed size, design, insulation and temperature range as to how many will be needed.
  • Experience shows that 0.17 to 0.28 square metres per minute (6 to 10 cubic feet per minute) is the usual requirement range.
Page last reviewed: 30 Oct 2023

 


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