By Sandy Stuttgen
Wisconsin’s soil types and weather patterns, which support the growth of a variety of forages, are ideal for raising cattle. In Wisconsin, we have two seasons that do not support cattle very well — cold winter and hot summer. But in general, even during those seasons, the length of time during which cattle may struggle is limited. Humid summer days have more of an impact on their well-being than wind-chilled winter days.
Heat and humidity
Both beef and dairy cattle prefer ambient temperatures of 55 to 60 degrees F, and they do not handle humidity very well. Their normal internal temperature is 101 degrees F. Their lung capacity is small in relation to their body size, so while panting helps, it may not be enough to cool them during hot, humid summer days. Cattle well-being suffers especially during humid days followed by evenings that do not drop below 70 degrees F, as under those conditions, cattle will not have a chance to recover before the next hot, humid day begins.
Heat and humidity make transporting cattle especially stressful. Pay attention to weekly and daily weather forecasts, and plan all hauling events accordingly, doing your best to avoid transporting cattle whenever possible during hot and humid days. If you must transport cattle, even for short trips between farm locations, keep hot weather transporting tips in mind.
Bear in mind the animals’ space requirements. Loading density charts such as the one included below are available from bqa.org. Increase space per head during hot weather conditions to maximize air movement. Loading fewer cattle and making more trips is an economically superior outcome than having cattle suffer heat stroke during the trip.
Plenty of air
When transporting on hot days, open all the trailer vents so there is plenty of air movement, and while driving the speed limit, make the trip as direct and efficient as possible. Make sure all animals are standing after being loaded and before starting out. It is best practice on long hauls to check animals after two hours on the road, and every four hours after that. If cattle must be hauled during times of high temperature and humidity, only stop if it is an absolute necessity.
If possible, stop during the cooler parts of the day or park in the shade when stopped, and keep stops as short as possible. Do not park near other vehicles, as doing so prevents ventilation; try to allow cross breezes to pass through the trailer in hot weather.
Avoid hauling cattle when the heat index (HI) is in the extreme range, greater than 100 (orange area on the HI chart below). Avoid hauling between 11 a.m. and 4 p.m. Early morning is the coolest time to haul, assuming the previous night was cool.
There really is no good time to haul during stretches of hot, humid days and nights; if possible, postpone transport until the weather breaks.
Cattle find transportation stressful, and in response, their internal temperature naturally increases a few degrees. Physiologically, it takes them three to four hours to lower their temperature from its peak. So think about what “early morning hauling” really means. During some hot, humid Wisconsin days, the extreme HI may begin by 11 a.m. Plan transport so cattle’s internal stress response temperature is not peaking or coinciding with the extreme HI. Ideally, animals should be out of the trailer and relaxing in shade around full water troughs, naturally bringing down their internal temperature, hours before the HI reaches extreme levels.
Stuttgen is the Extension ag educator in Taylor County, Wis. This column is provided by the University of Wisconsin Extension’s Wisconsin Beef Information Center.