Heat stress is an important challenge for poultry farmers, particularly in hot climates. Broilers can be affected when environmental conditions become too warm for their ability to maintain a comfortable body temperature.

Heat stress can reduce feed intake, affect growth, increase water consumption, reduce flock performance, and in severe cases contribute to mortality.

Recognising Heat Stress

Birds experiencing heat stress may show changes in behaviour.

Possible signs include:

  • Open-mouth breathing or panting
  • Increased water consumption
  • Reduced feed consumption
  • Birds spreading their wings
  • Increased resting
  • Reduced activity
  • Birds moving away from crowded areas

Severe heat stress can become an emergency requiring immediate action and professional assistance.

Provide Adequate Water

Water is particularly important during hot weather.

Farmers should make sure water is continuously available and that drinking systems are functioning properly.

Inspect:

  • Water tanks
  • Pipes
  • Drinkers
  • Water pressure
  • Leaks
  • Blocked drinkers

Increase Ventilation

Air movement helps birds lose heat.

Natural ventilation may be useful in some houses, while mechanical ventilation may provide greater control in others.

Fans should be inspected regularly, especially before periods of extreme heat.

Reduce Unnecessary Disturbance

Handling and moving birds can increase stress during hot periods.

Where possible, schedule routine activities during cooler periods of the day.

Avoid Overcrowding

High stocking density can make heat management more difficult because birds generate body heat and have less room to spread out.

Stocking density should be appropriate for the housing system, climate, ventilation capacity, and bird size.

Protect the House From Direct Heat

The roof and walls of a poultry house can absorb solar heat.

Good building design, suitable roofing, insulation where appropriate, shade, and adequate ventilation can help reduce the environmental heat load.

Keep Water Equipment Clean

Dirty drinkers can discourage water consumption and contribute to contamination.

Clean and inspect drinking equipment regularly.

Monitor Feed Intake

Birds may reduce feed intake during hot conditions.

This can affect growth because birds receive fewer nutrients when consumption falls.

Farmers should monitor feed consumption and investigate significant changes.

Feed During Cooler Periods

Where practical, feeding activity can be managed to encourage consumption during cooler parts of the day.

The specific feeding strategy should be appropriate for the farm's production system and should not compromise continuous access to feed.

Monitor the Flock Frequently

During very hot conditions, birds should be observed more frequently.

Check:

  • Bird behaviour
  • Water availability
  • Ventilation
  • Mortality
  • Feed intake
  • Litter condition
  • House temperature

Heat Stress Risk Checklist

Risk Action
High temperature Increase monitoring
Poor air movement Improve ventilation
Water shortage Restore supply immediately
Overcrowding Review stocking management
Roof heat Improve shading/design where possible
Wet litter Identify and correct water leaks

Do Not Ignore Mortality

Unexpected deaths during hot weather should be recorded and investigated.

If mortality rises rapidly or birds show severe signs of distress, contact a qualified veterinarian or poultry-health professional.

Power Supply Planning

Farms that depend on electrical fans should have a plan for power interruptions.

In areas where electricity supply is unreliable, farmers should consider appropriate backup arrangements suitable for the scale and design of the poultry house.

Water Storage

Water storage capacity should be sufficient for the farm's needs, particularly during periods when water supply may be interrupted.

Tanks should be maintained properly and protected from contamination.

Heat Stress and Profit

Heat stress can affect profitability through reduced feed intake, slower growth, increased mortality, and additional management costs.

Preventive environmental management can therefore have both animal-welfare and financial benefits.

Prepare Before the Hot Season

Do not wait until birds are already suffering from heat stress before checking equipment.

Before hot weather arrives:

  • Test fans.
  • Clean ventilation openings.
  • Inspect water systems.
  • Check backup power arrangements.
  • Inspect the roof.
  • Review stocking density.
  • Repair damaged equipment.

Final Thoughts

Heat management requires preparation, observation, water availability, ventilation, and appropriate stocking management.

Every poultry house responds differently to hot weather, so farmers should monitor actual conditions and bird behaviour rather than relying on a single environmental measurement.

When heat stress becomes severe or mortality increases unexpectedly, professional veterinary assistance should be sought promptly.