Combating Heat Stress in Poultry: Nutritional Strategies for Resilience

As global temperatures continue to rise, the poultry industry faces increasing challenges in maintaining bird health and productivity. Heat stress, a physiological response to elevated temperatures, is now one of the most significant stressors affecting poultry worldwide, especially in tropical and subtropical regions. This issue not only reduces productivity but also impacts bird welfare and immune function, leading to substantial economic losses.

Understanding Heat Stress and Its Effects

Poultry are highly sensitive to environmental temperatures, with an optimal thermal comfort zone of 16°C to 25°C. Exposure to temperatures beyond 30°C results in stress responses such as panting, reduced feed intake, dehydration, and altered metabolism. Over time, this can severely impair:

• Growth performance
• Feed efficiency
• Egg production and quality
• Meat quality
• Immune response and health

Modern breeds, while genetically optimized for productivity, have become increasingly vulnerable to such stressors, necessitating innovative strategies to maintain flock performance under heat load. For a deeper understanding of heat stress and other environmental challenges in poultry farming, explore our blog on Abiotic Stressors in Poultry Farming: Challenges and Mitigation Strategies.

Nutritional Manipulation: A Promising Solution

Nutritional intervention is among the most practical and cost-effective approaches to mitigate the negative impacts of heat stress. By modifying the bird’s diet, we can improve its physiological resilience, oxidative balance, and immune response. Here are some of the most promising strategies:

1. Supplementing Natural Antioxidants

Oxidative stress is a major consequence of heat stress, causing cellular damage and immune suppression. Natural antioxidants like Vitamin E, Vitamin C, and selenium play a critical role in neutralizing free radicals.

• Vitamin E (125–250 mg/kg of feed) improves feed conversion and immunity by reducing oxidative damage.
• Vitamin C (200 mg/kg of feed) supports adrenal function, calcium metabolism, and enhances egg quality.
• Selenium (0.1–0.3 mg/kg of feed) aids in antioxidant enzyme function and supports thyroid hormone metabolism002E

To learn more about how plant-based additives can further enhance antioxidant defenses, check out our blog on Phytogenic Feed.

2. Phytobiotics and Herbal Additives

Phytochemicals from herbs like curcumin, resveratrol, and lycopene possess antioxidant, antimicrobial, and anti-inflammatory properties.

• Curcumin (100–150 mg/kg of feed) enhances antioxidant defenses and immune markers.
• Resveratrol (300–500 mg/kg of feed) upregulates heat shock proteins and supports gut integrity.
• Lycopene (200–400 mg/kg of feed) improves meat quality and reduces lipid oxidation in tissues.

Discover how these phytochemicals interact with poultry genetics in our blog on Nutrigenomics in Poultry: Revolutionizing Nutrition Through Diet-Gene Interactions.

3. Probiotics and Prebiotics

Gut health is essential during heat stress, as intestinal permeability and dysbiosis can worsen systemic inflammation.

• Lactobacillus-based probiotics improve feed intake, egg quality, and immune response.
• Mannan-oligosaccharides (1 g/kg of feed) alleviate intestinal damage and enhance nutrient absorption.
• Synbiotics (probiotic + prebiotic) show synergistic effects in improving gut morphology.

4. Electrolytes and Osmolytes

Maintaining electrolyte balance is vital to prevent dehydration and acidosis during heat stress.

• Potassium chloride (0.5% in water) enhances growth and reduces mortality.
• Betaine (1000 mg/kg of feed) acts as an osmoprotectant, helping cells maintain hydration and function.

5. Organic Minerals

Organic forms of zinc, copper, and manganese are better absorbed and more effective under stress.

• Improve feed conversion, egg shell quality, and immune responses.
• Reduce oxidative damage in tissues and reproductive organs.

Science-Backed Results

Numerous studies validate the effectiveness of these dietary strategies. For example:

• Vitamin E + C + probiotics showed synergistic effects in improving feed intake and reducing mortality under heat stress.
• Selenium nanoparticles elevated antioxidant gene expression and improved performance metrics in broilers.
• Herbal blends such as garlic and rosemary improved feed efficiency and lowered stress biomarkers.

Conclusion

With climate change intensifying, the poultry industry must adopt holistic strategies to ensure sustainability. Nutritional manipulation offers a scientifically proven, field-friendly solution to combat the challenges posed by heat stress. By incorporating targeted feed additives, antioxidants, and gut health enhancers, poultry producers can not only mitigate the physiological burden of heat stress but also enhance productivity and profitability.

References

Abdel-Moneim, A. E., et al. (2021). Nutritional manipulation to combat heat stress in poultry – A comprehensive review. Journal of Thermal Biology, 98, 102915. https://doi.org/10.1016/j.jtherbio.2021.102915