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Dangerous heat index for livestock this week


The next few days will see much of NJ trapped in a heat index that is of significant concern for livestock with little air movement.

Cattle: Cattle have a lower tolerance for heat stress than humans. Cattle experience heat stress above 75 degrees F and with temperatures expected to be above 100 degrees in the shade, the solar heat on open pastures can soar to well into the 130’s.

Water consumption increases greatly, cattle will drink as much as 30 gallons a day. Clean fresh water that is pumped from the well as opposed to standing in tanks is of critical importance along with fans to move air. Black hided cattle have added stress due to the way light absorption works and converts to heat. Wind breaks that do not allow airflow are a danger to cattle as they congregate in the shade offered and to get away from flies. Emergency shade structures need to provide 25 square feet per animal to be useful. Separate cattle groups to reduce crowding if at all possible. Remove breeding bulls to reduce stress on cows in heat.

Cattle on feed in feedlot pens are at significant risk in this type of heat. Limiting grain will decrease the amount of heat animals create to digest feed. Air flow is essential for confined cattle. Separate cattle in pens to reduce overcrowding. Monitor respiration rate and signs of panting. Hose down cattle in distress. Cattle also cool down by standing in mud. Remember to drink a quart or two of water every hour while you are monitoring cattle.

Swine: Pigs are even more suceptible to heat stress than cattle and require sprinklers to cool them down sooner. Given the emergency level of temperatures this week, plan to water pigs down and if possible give them access to children swimming pools (weigh down with blocks).  For more information see

Poultry: Poultry will die in this type of heat wave. Prevention is key to limiting poultry deaths due to the combined high heat and high humidity. Move birds to a shaded location with natural and artificial airflow and increase cold water availability and numerous water locations. Avoid stressing birds. Do not chase them or allow guardian dogs to chase. Move guardian dogs into basements or a cool pen in the barn with a fan.

Sheep and goats can tolerate heat better than cattle, horses and swine. The same measures apply. Providing sun shade to limit solar radiation will help tremendously.