6 Ways to Manage Excessive Heat Loads in Feedlots
Coming off the back of one of the hottest and driest years and with more dry, hot years predicted, it’s a good time to start thinking about how you can prepare for Excessive Heat Loads (EHL) in your feedlots.
What is EHL?
EHL is when cattle’s biological system is overloaded by heat.
Like us, cattle are homeotherms, which means they need to maintain their body temperature in a very narrow range for their body tissue and cells to operate efficiently. Hot weather, such as that experienced in the Australian summer, can cause cattle’s body temperatures to rise beyond the optimal range, leading to reduced feed intake (and, therefore, production losses). In extreme cases, tissue and organ damage can occur. In some instances, this can lead to death. It is, therefore, essential that EHL is understood, prepared for, and well managed.
Ways to Manage EHL
Start by inspecting feedlots for the temperature influencing factors such as shade availability, airflow, stocking density, and water availability.
Understanding the microclimate of the feedlot by using a microclimate sensor or weather station can go a long way towards your preparedness. Having historical data of the temperature ranges in a feedlot, especially in relation to the local region, can allow you to better gauge from a regional weather forecast if you cattle will be at risk. Recent rainfall, wind conditions, and humidity also have an impact on a feedlot’s susceptibility to EHL conditions. These can be tracked in real-time with the appropriate sensors and telemetry.
It’s also important to consider the animal’s characteristics. Contributing factors to EHL risk include darker coats, feeding frequency (feeding increases body temperature immediately after), diet (heavy carb diet will lead to higher body temperatures than fatty diets), and of course, any existing health issues.
Develop an EHL event strategy
As with anything, it is much better to prepare ahead of time than being caught on the back foot. Develop a strategy and make sure everyone involved knows what they need to do. Ensure you’ve got enough water at the site, and if you’ve decided to install some temporary shading or sprinklers, then make sure you’ve got it sorted before it’s too late. During the warmer months, keep a close eye on the weather forecasts for incredibly hot days that could lead to EHL events.
Provide sufficient shading
The shade has a massive impact on body heat, so think carefully about whether you’ve provided enough and whether it will be sufficiently effective. Position the shade so it is accessible to the cattle at all times of the day and should allow sufficient airflow, which can be achieved by height and either using shade cloth or cutting holes in steel/wooden shading.
Cooling with Sprinklers
Avoid sprinklers in hot and humid climates; however, in hot and dry conditions, they can be beneficial. Sprinklers should produce large water droplets of at least 150 microns, should be far enough away from water troughs and feed bunks so as not to contaminate them and be applied for 5-10 minutes, and then 15-20 minutes off, to allow for cooling by convection. A remote irrigation control system can help you to schedule and control this right from your phone.
Keep a close eye on your cattle
If more than 10% of your cattle are showing signs of fast panting and drool or foaming at the mouth, then you should start taking actions to reduce heat impact and immediately stop all handling and movement. The cattle will also tell you how they are feeling with their behavior; seeking shade, body splashing, and appearing agitated may be shown. Dry matter intake will also decrease under excessive heat.