Iowa has been under a Heat Stress Alert for two days, and although the weather situation might break for a couple of days, the forecast for late this week and early next week indicates the state could be facing an alert situation again.
Managing Heat Stress in Cattle
As temperatures heat up during the summer, cattle producers need to assess the heat stress that their cattle are under. Compared to other animals, cattle rely on respiration more than sweating to dissipate their heat load. Since cattle do not dissipate heat effectively they accumulate a heat load during the day and dissipate heat at night when it is cooler. During extreme weather conditions with insufficient environmental cooling at night, cattle will accumulate heat that they cannot disperse.
Typically physiological factors such as hide color, weight and animal health predispose cattle to heat stress during the summer months. To minimize heat stress, cattle producers can start now initiating measures in their operation to assist cattle in managing periods of hot, humid weather.
1. Make sure cattle have access to EXCESS WATER CAPACITY. This means getting extra water tanks into pens filled with fresh water. During the heat of the day (noon through sundown) cattle may increase their water demand to 2 gallons per 100 lbs of body weight.
2. Do not handle or process cattle past 9:00 am.
1. Shift feeding to provide 70% of the day’s feed delivered after sundown.
2. Provide shade. A minimum of 20 square feet per head of shade is recommended.
3. Remove restrictions to air flow, such as wind breaks.
4. Provide mounds for cattle to make use of what little breeze may be available.
5. Grind light-colored bedding, such as straw or grass hay, into the pens. This will provide a cooler surface to rest on than the dark-colored pen surface.
1. When heavy, black-hided cattle show signs of severe heat stress such as continuous, open-mouthed panting, get these cattle to a shaded area, and cool these cattle with a hose, including their head and body. Either a stream of water or of large droplets which will penetrate through the hair coat to the skin is critical to provide evaporative cooling.
In addition to management practices, cattle producers can monitor forecasted heat stress events at www.ars.usda.gov/Main/docs.htm?docid=20426. For more information on preventing heat stress in cattle go to vetmed.iastate.edu/ and type “heat stress cattle” in the search box.