Keep your flock strong during heat stress!

Heat stress is a major constraint in poultry production systems, particularly as global temperatures rise due to climate change. Exposure to elevated ambient temperatures, especially when coupled with high relative humidity, can severely compromise poultry welfare, growth rates, feed efficiency and reproductive performance. This article examines the clinical indicators, underlying physiological responses, risk factors and state-of-the-art interventions for managing heat stress in poultry flocks.

Clinical signs and pathophysiology of heat stress

Chickens are homeothermic animals with limited capacity for evaporative cooling, as they lack sweat glands. Thermoregulation under heat stress relies primarily on increased respiratory evaporation (panting) and behavioral modifications.

Key clinical signs of heat stress include:

🐔 Elevated respiratory rate and open-mouth panting.
🛋️ Lethargy, decreased locomotor activity, and increased recumbency.
🕊️ Wing spreading and feather elevation to enhance heat dissipation.
🍽️ Reduced voluntary feed intake, leading to decreased growth rates and lower body weight gain.
💧 Increased water consumption, which may alter mineral balance and contribute to electrolyte disturbances.
🥚 In layers: reduced egg production, thinner eggshells due to impaired calcium metabolism and increased incidence of shell defects

Severe, prolonged heat stress can result in acute mortality, particularly in fast-growing broiler strains and at high stocking densities.

Risk factors and etiology

The primary drivers of heat stress in poultry are:

Ambient temperature: sustained environmental temperatures above the thermoneutral zone (>25°C for most breeds).
Relative humidity: high humidity impairs evaporative cooling via panting.
Ventilation: inadequate airflow exacerbates heat accumulation.
Stocking density: overcrowding limits heat dissipation.
Diet composition: high-protein diets increase metabolic heat production (specific dynamic action of protein).

Evidence-based mitigation strategies

Environmental management:

• Optimize ventilation rates and airflow patterns to facilitate convective and evaporative heat loss.

• Provide unrestricted access to cool, clean drinking water.

• Adjust lighting schedules to minimize activity during peak heat periods.

• Reduce stocking density during hot weather events.

Nutritional interventions:

• Reformulate diets to reduce crude protein content and increase energy density via supplemental fats.

• Supplement with functional feed additives that support osmoregulation, gut integrity, and stress resilience.

Role of betaine-based feed supplements

Jodoco offers advanced nutritional solutions for mitigating heat stress:

Jodobet®: A natural betaine source that acts as an osmolyte, supporting cellular water balance and stabilizing intestinal epithelial function under osmotic stress. Betaine supplementation has been shown to improve feed intake, growth performance, and survivability in heat-stressed poultry.
Jodoplume: Combines betaine with organic acids to enhance metabolic efficiency and gut health.
Pure C Beta: A synergistic blend of vitamin C and natural betaine, targeting both oxidative and osmotic stress pathways.

These supplements can be administered via feed or drinking water, allowing for flexible and rapid implementation during periods of acute heat stress.

Protect your flock from the adverse effects of heat stress with Jodoco’s scientifically formulated solutions. 

References

DEFRA. (2005). Heat stress in poultry. Department for Environment, Food & Rural Affairs. https://www.gov.uk/government/publications/heat-stress-in-poultry
ILVO. (n.d.). Heat stress in laying hens. Institute for Agricultural and Fisheries Research. https://www.ilvo.vlaanderen.be
Landbouw en Zeevisserij Vlaanderen. (n.d.). Heat stress in poultry. https://www.vlaanderen.be/landbouw/hittestress-bij-pluimvee
Pluimveeweb. (n.d.). Attention: Heat stress. https://www.pluimveeweb.nl
Aviagen. (2016, July). Broiler management in hot weather, Ross Note. https://en.aviagen.com
Cobb-Vantress. (2022, May). Heatstress. Cobb Technical Focus. https://www.cobb-vantress.com
Hittestress.nl. (n.d.). Poultry – Heat stress. https://www.hittestress.nl