By Robert Pore
Central Nebraska is going through a hot, dry spell which is expected to continue through June and into July.
Day-time temperatures have been averaging in the 90s. Hot and humid continues not only make it uncomfortable for humans, but for cattle, which Nebraska has a lot of.
With the onslaught of warm temperatures early in the season, Nebraska Extension said cattle have had little opportunity to become acclimated to summer conditions this year. Average daily temperatures in June, for Grand Island, according to the National Weather Service, have been averaging nearly 6 degrees above the 30-year average.
Extension experts said helping cattle cope is critical as the combination of hot temperatures, high humidity, and lack of air movement can cause severe cases of heat stress for cattle and can result in reduced intakes and gains, and in extreme cases, death.
According to Extension, cattle do not handle heat stress as well as humans. The range of temperature in which cattle do not use additional energy to maintain core body temperature is referred to as the thermoneutral zone.
“This zone generally ranges from 32 degrees F to 75 degrees F for cattle but can vary depending on metabolic size,” according to an Extension news release. “When temperatures exceed the upper critical temperature, cattle expend energy in attempt to dissipate heat. Panting and elevated respiration and heart rate are signs that this is occurring. When temperatures remain above 70°F during the night, cattle are unable to recover before the next episode of heat exposure.”
Some heat stress mitigation strategies to consider include, according to Nebraska Extension:
— First and foremost, providing plenty of water and space around water tanks for each animal. When the temperature is above 80 degrees F, cattle require nearly twice as much water (up to 30 gallons per head per day).
— Sprinklers with a large droplet size can be effective in cooling cattle and pen surfaces in dry conditions; however, limit use when humidity and moisture are high.
— Removal of excess manure is critical. When manure builds up, it holds moisture and increases humidity.
— Bedding pens is also an option to help lower the temperature of the pen surface.
— Providing shade can help reduce the heat load on cattle up to 20 degrees. Again, providing adequate space per animal is important when using shade structures. Overcrowding will have very little production benefit.
— Avoid working or transporting cattle during extreme temperatures. If necessary, handle cattle early in the mornings and not any time after 10 a.m.
— Consider reducing the amount of feed delivered in the morning to help lower the heat load on cattle, starting the morning before a heat event occurs.
— Improve air flow by incorporating tall mounds and placing cattle in pens with fewer windbreaks in the summer.
Nebraska Extension said to monitor weather frequently for potential heat events.
“Keep an eye out for predicted temperatures in the high 80s and 90s, especially following a rain and in situations where the wind speed is going to be less than 5 mph for several days,” said Extension experts.
The Temperature Humidity Index chart, U.S. Meat Animal Research Center Cattle Heat Stress Forecast, and Nebraska Mesonet Cattle Comfort Index can be helpful in determining when cattle are at risk for heat stress.
“Being proactive rather than reactive is important for avoiding any train wrecks when it comes to heat stress.” they concluded.