Dangers of Heat Stress on Your Livestock

Apr 20, 2023

Livestock farming is a crucial part of our food supply chain, and it's also important to ensure the welfare and well-being of the animals under our care for ethical reasons. One of the significant challenges faced by farmers and livestock producers is managing the impact of heat on their animals. High temperatures and humidity can cause heat stress in livestock, which can have severe consequences on their health and productivity, and can even be fatal.

Heat stress in animals occurs when they are unable to regulate their body temperature adequately. This can lead to decreased feed intake, reduced milk production, lower fertility rates, and increased susceptibility to diseases. This is why it's crucial to understand how you can reduce the impact of heat stress on livestock, via maximum ventilation and airflow in their sheds.

How hot is too hot for livestock?

Different types of livestock have varying levels of tolerance to heat stress. However, a general guideline is that when the temperature-humidity index (THI) exceeds 72, animals are at risk of heat stress. The THI takes into account both temperature and humidity to give a better indication of how hot it feels to the animals. For example, a temperature of 30°C and 60% humidity would result in a THI of 72.

It's essential to monitor THI regularly, especially during the hottest times of the day, to ensure that the animals are not exposed to dangerous levels of heat stress. High temperatures can cause animals to pant excessively, seek shade, and reduce their feed intake, leading to dehydration, exhaustion, and even death.

What temperature is too hot for sheep?

Sheep are among the most heat-tolerant livestock, and they can tolerate temperatures up to 32°C if they have access to shade, water, and a breeze. However, if the temperature exceeds 32°C, it's crucial to provide additional cooling measures, such as sprinkler systems, fans, or shade cloths, to reduce the impact of heat stress.

Sheep with dense wool coats are more susceptible to heat stress than those with finer coats, as they are less able to dissipate heat. This is why it's crucial to shear them before the hot season to improve their ability to regulate their body temperature.

What temperatures can cattle tolerate?

Cattle are less heat-tolerant than sheep, and they can start experiencing heat stress at temperatures as low as 25°C. They prefer temperatures between 5°C and 20°C, and can even tolerate up to 28°C if they have access to shade, water, and a cooling breeze.

During hot weather, cattle will seek shade and reduce their activity levels to conserve energy and prevent overheating. It's crucial to provide shade structures, such as trees, shade cloths, or sheds, to ensure that they have a place to rest and avoid direct sunlight.

What are the consequences of heat stress?

Animal heat stress is a significant concern for livestock producers as it can have a major negative economic impact resulting from reduced production and reproduction performance, and increased mortality. The effects of heat stress on production can vary, because many of the drawbacks are immediately apparent, but others manifest only much later.

During heat stress, animals tend to reduce their feed intake to decrease metabolic heat production, which results in reduced milk production in dairy cattle and lower growth rates in beef cattle, swine, and poultry.

Animals may also redirect their energy toward heat dissipation or managing health issues caused by overheating, affecting productivity. It’s also been shown that animals do not easily switch back to production mode after suffering heat stress, leading to possible decline in production performance even months down the line after they have recovered.

One of the main things heat stress can cause is a condition called "leaky gut," which occurs when an animal's core body temperature rises, causing blood flow to shift from the gastrointestinal tract to the skin surface for heat dissipation. As a result, the amount of oxygen and energy available to the intestinal lining decreases, leading to the weakening of the tight junctions that keep the enterocytes together. This weakens the gut lining, allowing pathogens and toxins to pass into the bloodstream and cause inflammation.

Inflammation caused by this will divert a lot of the animals energy from other vital functions such as growth, reproduction, and milk, meat, or egg production.

Heat stress can also result in lameness in cattle and swine, even after their temperature has returned to normal. This is because chronic inflammation can reduce the growth of keratinocyte that makes up foot horn tissue. If the animals don’t develop strong hooves in the summer, they can become lame in autumn as a result. Heat stress will also force an animal to stand for longer periods of time too, which can cause other foot issues. Furthermore, standing in the water from sprinklers for a long time can also soften hooves, and lead to mobility issues.

Heat stress also contributes to seasonal infertility, which can affect conception rates, litter size, and embryo mortality. During heat stress, animals experience a reduced feed intake causing a reduction in estrus signs, conception rates, and the number of embryos produced. Sows suffering from heat stress will have a reduced litter size, fewer weaned pigs, and fewer marketed pigs down the line.

Proper management of heat stress in livestock is crucial for preventing negative effects on production factors such as feed intake, growth, and reproduction. Techniques such as providing shade, adequate ventilation, and sufficient water sources can help mitigate the impact of heat stress on livestock, ultimately benefiting the health and productivity of the animals and the producers' bottom line.

How can we reduce heat stress in livestock?

There are several ways to reduce the impact of heat stress on livestock.

Insulate their shed

Proper insulation can help to maintain a more consistent temperature inside the shed, reducing the impact of external heat. Insulation materials can include foam, fibreglass, or reflective foil.

Improve ventilation

Good ventilation is essential to ensure that the air inside the shed circulates correctly, removing hot and stale air and replacing it with fresh, cool air. Natural ventilation can be achieved with windows, vents, or doors, while mechanical ventilation can be achieved through fans or exhaust systems.

Provide shade

Shade structures can help to reduce the impact of direct sunlight on the animals, reducing their exposure to heat. Providing shade structures is crucial in reducing the impact of heat stress on livestock. Portable shelters, such as those created by Outpost Buildings, can be an effective solution in areas where permanent structures aren’t feasible or practical. Additionally, being able to reposition your shelter helps to point them away from direct sunlight, or to catch the right breeze and much more.

Outpost Buildings' portable shelters are designed to provide maximum ventilation and airflow while protecting the animals from direct sunlight and heat. The shelters are also made from high-quality materials to ensure durability and longevity under harsh elements.

Sprinkler systems

Sprinkler systems can be used to cool the animals and their surroundings by spraying a fine mist of water. This can help to reduce their body temperature and increase their comfort level. It’s important not to over rely on sprinklers however, as keeping the animals damp for a long period of time can lead to other health issues, such as the softening of hooves mentioned above.


Fans can be used to create a cooling breeze inside a shed, helping to circulate the air and remove heat. Ceiling fans, wall-mounted fans, or portable fans can all be used depending on the size and layout of the shed.

Water access

Providing clean and cool water is very important when it comes to reducing the impact of heat stress on livestock. All your animals should have access to water at all times, and the water should be replenished regularly to ensure it's fresh and cool. This way, they can partially regulate their own temperature as needed.

Feeding management

During hot weather, animals may reduce their feed intake, which can lead to a decrease in productivity and an increased risk of heat stress. Therefore, it's essential to provide fresh feed for them, and to feed the animals during the cooler parts of the day when they’ll be more interested in it. This allows you to keep their energy levels higher without forcing them to eat when it’s uncomfortable for them.

Get a shed to keep your livestock cool today

Overall, heat stress is a significant challenge for livestock producers, and it's important to find ways to reduce its impact on the animals' health and well-being. Providing maximum ventilation and airflow, shade structures, sprinkler systems, fans, and water access are just some of the ways to reduce heat stress in livestock.

Proper insulation and ventilation are also essential in maintaining a consistent and comfortable temperature inside the shed. By implementing these measures, livestock producers can ensure that their animals remain healthy and productive, even during the hottest days of the year.

Outpost Buildings' portable shelters can also be an effective solution in providing shade and protection for the animals, especially in areas where permanent structures won’t fit or are otherwise unavailable.

Talk to us today to find out more about our shade solutions, and we can help you keep your animals cool and safe from the sun on those midsummer days.

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