Wondering how farmers reduce heat stress in broiler chickens? Heat stress in broiler chickens interferes with the birds’ comfort, suppresses productive efficiency, and may lead to high mortality.
High temperatures harm raising broiler chickens in business, and if combined with high humidity, the damage is worse.
The article discusses how heat stress impacts broiler chickens and proposes ways for poultry producers to minimize its negative effects on their performance.
What is Heat Stress in poultry?
Imagine you’re wearing a heavy coat on a really hot day – that’s kind of what chickens go through when it gets too warm outside. You see, chickens and other poultry don’t sweat like we do.
They have feathers covering most of their body, which is great for keeping them warm, but not so great when it’s hot out.
Heat waves can be harmful to broiler chickens. When the temperature rises too high, they can struggle to cool down, they must make significant changes to regulate their body temperature and avoid overheating.
If broiler chickens get too hot for too long, it can make them sick or even be fatal. That’s why farmers have to be really careful about keeping their birds cool, especially on scorching summer days.
Causes of heat stress in broiler chickens
Poultry thrives in a narrow temperature range. When the environment exceeds that zone, birds struggle to regulate their body heat, leading to dangerous heat stress. Key factors include:
1. High Temperatures – This is the most obvious one. When it gets really hot outside, especially above 30°C (86°F), broiler chickens start to struggle. As exterior temperatures rise above ideal levels, chickens have trouble dissipating rising internal heat.
2. High Humidity – It’s not just about temperature. When it’s humid, it’s harder for chickens to cool down by panting because the moisture in the air prevents birds from releasing heat through their respiratory tract and skin.
3. Poor Ventilation – Without good airflow, hot air gets trapped around the chickens. Imagine being in a stuffy room with no windows open on a hot day.
4. Overcrowding – If too many chickens are packed into a small space, their body heat adds up quickly. It’s like being in a crowded room – it gets warmer faster and this affects their growth.
5. Thick/wet litter – Excess litter depth and moisture content trap heat in poultry housing, contributing to internal temperature rise.
6. Feeding times: Believe it or not, digestion produces heat. So if chickens eat a big meal during the hottest part of the day, it can make them even warmer.
7. Age and health: Younger and older chickens, as well as those that are already sick, tend to be more sensitive to heat.
8. Breed differences – Some chicken breeds, especially heavier ones or those with lots of feathers, are more prone to heat stress than others.
9. Direct sunlight – Just like how you’d feel hotter standing in the sun versus the shade, chickens can overheat if they’re exposed to direct sunlight for too long.
10. Lack of water – Chickens need to drink more when it’s hot. If they don’t have enough cool, clean water, they can’t regulate their body temperature as well.
11. Breed differences – Some chicken breeds, especially heavier ones or those with lots of feathers, are more prone to heat stress than others.
Signs of heat stress in poultry.
Some signs that a chicken is feeling too hot include:
- Pale combs and wattles: The combs and wattles are normally bright red, but they will become pale or pinkish if a chicken is heat-stressed.
- Increased water consumption: Chickens will drink more water than usual to stay hydrated.
- Decreased egg production and poor egg quality (Breeders).
- Panting and difficulty breathing with their beaks open (like a dog).
- Diarrhoea.
- Decreased feed consumption.
- Reduced Activity: Hot chickens become tired and may lay down the coop floor.
- Drooping wings: Chickens will often hold their wings out away from their bodies to increase the surface area for them to stay cool.
- Increased mortality.
Panting and difficulty breathing
This is the most common sign of heat stress in broiler chickens. They will pant with their beaks open, rapidly breathing to try and cool down. Read also: Reducing Early Chick Mortality: Causes and Solutions.
Panting typically occurs when temperatures approach or exceed 30 °C. Broilers cannot tolerate the combination of high heat and moisture, risking rapid death from heat exhaustion, especially in broiler birds.
Decreased feed consumption
Hot environments cause decreased feed consumption, which translates to lower nutrient intake. Lower nutrient intake means less metabolic heat production, facilitating heat management despite slowed growth.
Research shows that broiler mortality risk increases as feed intake goes up during heat waves, particularly at the hottest times of day.
Managing Heat Stress in broiler chickens
Here are some key ways that you can help reduce the effects of heat waves on your broiler flocks.
Have a Heat Management Plan
Before starting a new flock, have a solid plan for handling heat waves. This includes appropriately designed housing, ample shade and water, movement protocols, and backup options for extreme weather.
Closely monitor flocks to recognize signs of heat stress and know how to respond. Recognize the common behaviour patterns and signs indicating when birds are in distress.
Housing Design and Temperature Control
Prolonged heat exposure stresses broilers and causes health problems. Ensure housing design has good ventilation and cooling to keep broiler chickens comfortable and safe.
If temperatures climb, take action to reduce building heat, like opening windows, using fans/misters, or adding air conditioning. Avoid overcrowding, which compounds heat issues, by providing recommended floor space per bird.
Ventilation and Shade
Maximize shade and airflow, essential for cool temperatures, especially in hot weather. Fans are essential for promoting the necessary airflow. You should consider installing a water spray system as a supplement to natural cooling.
Litter Management
Thick litter retains more heat, so routinely replace old litter with fresh bedding. If unable to swap fully, reduce old litter depth by two inches to discourage heat build-up. To maximize the cooling effect, it is essential to ensure that the litter remains dry, as moist litter intensifies heat.
Provide Cool, Clean Water
Well-hydrated broilers are better equipped to cope with heat-induced stress and nervous system strain.
It is crucial to guarantee the uninterrupted availability of fresh and cold drinking water to minimize the adverse effects of heat effectively. Add ice to reduce the water temperature as needed.
Supplementing Addictives and Vitamins
Adding an electrolyte/vitamin mix to poultry drinking water aids heat stress relief. The supplementary vitamins and electrolytes promote hydration, keeping birds refreshed.
Proper electrolyte balance also supports overall well-being and allows the flock to better recover from heat effects.
Feeding Adjustments
Allow early morning feeding when temperatures are cooler, avoiding midday/afternoon peaks. Temporary nighttime feedings around 5 PM are also an option once the extreme heat subsides. This aids digestion and prevents internal temperature spikes.
To prevent too much body heat, it’s advised to feed balanced diets with slightly less protein and add synthetic amino acids like methionine and lysine as supplements.
Benefit of Feed Withdrawal. (Fasting)
Fasting before or during hot periods reduces heat production from nutrient digestion and metabolism. Fasting also has a calming effect, as muscle contractions generate more unwanted heat. Once temperatures start dropping, broilers typically resume eating.
Increase water intake
Panting causes more water loss, so more water intake helps prevent dehydration. Cool drinking water stimulates both feed and water consumption. When below body temperature, water absorbs body heat.
Thus, cool, plentiful drinking water is extremely important. Generally, increased consumption aids survival. Some research attributes supplemental salt benefits, like increased thirst and intake, to the salts themselves.
Summary
In summary, broilers require physiological adjustments to cope with heat stress. To prevent heat stress in broilers, it is important to provide ventilation, shade, temperature control, access to water, monitor stocking density, and adjust feeding schedules according to the weather.
