“Heat Stress Interventions”
by Chris Reinhardt, feedlot specialist
Prevention is better than a cure—for virtually any disorder we can think of. But this is especially pertinent if you’re a cattle feeder going into summer heat. We know that we can intervene in the event of extreme heat events to prevent cattle death. But by that point cattle have likely been off feed for a protracted period and performance has been lost; we’re just happy to save the cattle.
The most effective and surest preventative of extreme heat stress for black-hided cattle is some sort of shade structure. We often see this in pasture cattle: even though extremely hot, humid conditions may exist on pasture, if cattle can find shade during the hottest part of the afternoon, they will be back out grazing after the sun begins to set. Shades can be sturdy, permanent structures, mobile, portable structures, or temporary structures using a frame with cloth overhead. Costs will tend to follow the permanence of the design. Also, the shade portion of the structure does not need to be solid; partial shade is better than no shade.
Another preventative measure is light-colored bedding. Recent K-State research (Rezak et al., 2012) suggests that during high heat days, the surface temperature of chopped hay or straw is 25°F cooler than that of the bare dirt floor and provides a cooler place for cattle to lay down and rest. And resting improves performance.
Other research suggests that wetting the surface of pen mounds in the morning prior to extreme heat can reduce surface temperatures and reduce heat load of cattle. The water essentially is “cooked off” by the radiant heat of the sun, and the evaporating water is taking heat with it from the pen surface. Without the water, the surface would simply absorb this heat and transfer it back to the cattle. However, the downside of this approach is that by adding water we may also be contributing to humidity conditions.
The key in all of these examples is to get interventions in place prior to the extreme heat event, give cattle a chance to utilize and benefit from the relief measures, and be prepared—summer is coming.
