By Learnmore Chiposo | Supra Feeds
Summer brings high temperatures, which can cause broilers to suffer from heat or summer stress. This condition arises when there is an imbalance between heat production and heat loss in the birds' bodies. If left unchecked, heat stress can lead to significant losses, including poor growth, low feed consumption, high feed conversion ratios (FCR), and increased mortality. These challenges are exacerbated in high-humidity environments.
Broilers thrive in temperatures between 22-28°C, known as the Thermoneutral Zone (TNZ). Beyond this range, heat stress symptoms such as reduced feed intake, stunted growth, and increased mortality become evident. Unlike humans, broilers lack sweat glands, have full feather coverage, and are naturally fatty, making them particularly susceptible to overheating.
Effects of Heat Stress
Heat stress leads to immunosuppression, leaving broilers vulnerable to infections. It also disrupts their acid-base balance, causing respiratory alkalosis and oxidative stress. Observable behavioral changes include:
Increased water intake
Reduced feed consumption
Panting
Reduced movement
Elevated wings
Internally, birds may experience metabolic disorders, poor protein digestion, and impaired production efficiency, resulting in decreased growth and higher mortality.
Practical Tips to Manage Heat Stress in Broilers
1. Water Management
Water is critical in mitigating heat stress, as broilers consume 3-4 times more water than feed during summer. Key practices include:
Always provide clean, cool water fortified with vitamins and minerals to stimulate appetite and enhance performance.
Maintain water pH between 5.5-6 using nutritional acidifiers.
Regularly clean and flush water pipelines with organic acids or hydrogen peroxide.
Treat water with quality sanitizers to prevent health-related issues.
2. Housing Management
Proper housing design and maintenance are essential:
Orient poultry houses east-west to minimize heat penetration.
Use full brick walls (2-2.6m) on the eastern and western sides, and ensure proper ventilation with wire mesh on the northern and southern sides.
Keep curtains open during the day for air circulation.
Reflect heat by painting roofs white or using foggers to cool the space.
Maintain stocking densities of 30 birds/m² (day-old to 14 days) and 8-10 birds/m² (15 days to slaughter).
3. Feed Management
Feed intake decreases as temperatures rise, so it’s important to optimize feeding practices:
Feed birds during cooler hours (morning and evening).
Ensure adequate feeder space: provide 3 x 14kg feeders per 100 birds at an appropriate height.
Ensure sufficient drinkers: provide 3 x 12L water fonts per 100 broilers with heights aligned to the birds' backs.
4. General Management
Maintain litter depth at 8-10cm.
Provide 10% additional floor space during summer to reduce heat accumulation.
Conduct placement, vaccination, and transportation during cooler parts of the day.
Use foggers to lower shed temperatures by 5-10°C, depending on quality.
Conclusion
Effective management of water, housing, feed, and general practices is critical for minimizing heat stress in broilers. Mastering these techniques ensures healthy birds, improved productivity, and better profits despite challenging summer conditions. Heat stress mitigation isn't just about survival; it’s about optimizing broiler welfare and achieving sustainable farming success.