Ben Holland, South Dakota State University (SDSU) extension beef feedlot specialist, offers ways to relieve heat stress in cattle.
1. Provide adequate drinking water. A minimum of 1.5 in. of space at water tanks/animal is necessary. In addition, make sure water flows are sufficient to keep up with the requirements of the animal. The water delivery system must also be able to deliver 1-2 gals./hour for each animal in the feedlot. Make arrangements for additional tanks or emergency water supplies before the stress episode occurs.
2. Minimize cattle movement during hot episodes. Cattle should be in working areas no more than 30 minutes. If cattle transportation or working must occur, do this in the early morning.
3. Consider late-day feeding. If 70% or more of the daily feed delivery is delivered 2-4 hours after the hottest part of the day, peak fermentation (which generates heat) occurs during the coolest part of the night. This prevents additional heating of the animals in the day and can allow more heat of fermentation to dissipate. When cattle decrease feed intakes during hot periods, do not try to make that back up in one or two days after the heat episode ends. Utilize gradual increases in feed delivery over a period of several days, and become more cautious as intakes approach the pre-heat levels.
4. Utilize water to wet areas of pens. If pens are wetted, this provides a cool place for cattle to lie at night so heat can dissipate from the cattle. Approximately 10-14 sq. feet/animal is recommended, and if the pen surface is wetted, apply water to the mound area.
5. Control biting flies by paying attention to detail in pen and feedlot hygiene, removing weeds and brush within 150 feet of feedlot pens, minimizing shallow pools of water and using facility sprays.