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Heat Stress in Poultry : Maintaining Feed Intake and Performance

Heat Stress in Poultry

Cause, consequences and solutions.

Heat stress is a major challenge in poultry production, with immediate effects on feed intake and performance. As temperatures rise, birds reduce their feed consumption, leading to losses in growth, egg production and flock uniformity. Feed intake depression is often the first visible sign of heat stress. Anticipating and mitigating its impact is therefore essential to maintain performance under hot conditions.

Temperatures and limits

- - T° > 32°C
  - H > 80%

poultry under

heat stress

The optimum temperature for poultry is around 20°C.

Above 28°C, the animals’ comfort is compromised.

Effects of heat stress

>60%

of the drop

in performances

Heat stress causes a drop of more than 60% in performance due to reduced feed intake and impact on metabolism.

Consequences of heat stress

Feed efficiency

Inflammation

Animal performance

Résistance animale

Animals are less efficient, more expensive and more susceptible to diseases, resulting in significant economic losses.

More information

on the heat stress

Why heat stress is a critical challenge in poultry ?

Heat stress is one of the major challenges in modern poultry production, particularly in regions exposed to high temperatures or prolonged heat periods. Poultry have a limited thermoregulation capacity, making them highly sensitive to increases in ambient temperature.

When temperatures rise, the animal’s response is rapid: appetite decreases in order to reduce metabolic heat production. This reduction in feed intake is often the first visible indicator of heat stress and typically occurs before any measurable decline in zootechnical performance.

In both broilers and layers, the impact of heat stress is immediate, affecting growth rate, feed efficiency, egg production and flock uniformity. Without an adapted nutritional strategy, these effects can persist and lead to significant economic losses.

How do the biological mechanisms of heat stress work?

Behavioural changes

Under high temperature conditions, poultry feeding behaviour is significantly altered. Feeding activity is reduced, as birds voluntarily limit feed intake to decrease internal heat production. Feeding patterns also change, with shorter and more irregular meals, often concentrated during cooler periods of the day.

At the same time, water consumption increases sharply, becoming the primary means of thermoregulation, often at the expense of feed intake.

Physiological consequences

Heat stress leads to increased oxidative stress, resulting from an imbalance between free radical production and the bird’s antioxidant defence systems. This situation can negatively affect digestive function and the animal’s ability to efficiently utilise nutrients.

Impaired digestive efficiency, combined with reduced feed intake, results in poorer nutrient utilisation and increased performance variability within the flock.

What are the nutritional levers to mitigate heat stress?

Supporting feed intake

The first nutritional lever when facing heat stress is to preserve feed intake. Maintaining feed attractiveness is essential to encourage voluntary intake, even under challenging environmental conditions. A more consistent feed intake helps limit sudden performance drops and supports overall production stability.

Supporting adaptation to stress

Beyond feed intake, specific nutritional approaches aim to support the physiological balance of poultry exposed to heat stress. These strategies help improve the animal’s ability to adapt, reduce the negative impact of stress on digestive and metabolic functions, and limit performance variability between birds.