Farmers use a livestock heat stress index (a combination of heat and humidity) to determine when heat stress could create a problem for their animals. But don’t want until temps reach the danger zone to help your animals, and no matter what the species, the most important thing producers can do is provide cool, clean water and shade.
Dairy cows start to experience mild heat stress at a heat index of about 68 degrees. They need water (a 1,500-pound dairy cow producing 80 pounds of milk per day will drink 33 gallons of water a day in 80-degree weather); shade; fans; sprinklers (just not over the stall beds, as the increased moisture can contribute to mastitis); misters; or tunnel ventilation with cooling cells (smaller barns). Focus on the holding pen and milking parlor.
Talk to your nutritionist about changing the ration to decrease heat produced by fermentation. And pay attention to your fresh cows because they’re more susceptible to heat stress.
2 Beef Cattle
Typically pastured cattle are not as susceptible to heat stress as feedlot cattle or cattle confined to a barn.
Cattle should not be worked during times of extreme heat and only early in the morning when it is hot. Don’t work them in the evening even if it has cooled off a little — that’s because a cattle’s core temperature peaks 2 hours after peak environmental temperature. It also takes at least 6 hours for cattle to dissipate their heat load.
Consumption of water is the quickest method for cattle to reduce their core body temperature. Rule of thumb is that cattle need 3 inches of linear water space per head during the summer, so add extra water tanks prior to extreme heat events so that cattle become accustomed to them. And keep the tanks clean.
Cattle heat production from feed intake peaks 4 to 6 hours after feeding, which means heat production in cattle fed in the morning will peak in the middle of the day when environmental temperatures are also elevated. Not good. It’s recommended cattle receive a least 70 percent of their feed 2 to 4 hours after peak ambient temperature.
Pigs are much more sensitive to heat than other animals because they lack the ability to sweat. Signs of stress in pigs include: open-mouth breathing, vocalization, blotchy skin, stiffness, muscle tremors and the reluctance to move. If pigs begin to express signs like these, allow them to rest. It is also helpful to gently sprinkle cool water on the pig. Do not pour large amounts of cold water on the pig as this may send the pig into shock.
Additionally, it is important to provide shade for pigs housed outside.
4 Sheep and goats
Sheep and goats tend to be less susceptible to heat stress than other livestock, and goats tend to tolerate heat better than sheep.
Wool protects sheep from extreme heat as well as extreme cold. Spring shearing allows sheep to have adequate wool growth to keep them cool in the summer (and avoid sun burning).
During periods of extended heat and humidity, it may be necessary to provide extra water and clean and change waterers more often. On average, a sheep or goat will drink one to two gallons of water per day.
Horses have difficulty regulating their body temperature when temperatures exceed 90 degrees. If humidity is high, the temperature doesn’t even have to reach 90 degrees to become dangerous.
It’s important that your horse has access to cool, clean water at all times. Even non-working horses will double their water intake during hot weather. On average, a 1,100-pound horse consumes 4 to 9 gallons of water per day.
Fresh pasture contains between 60-80 percent moisture and provide a large amount of the horse’s water requirements when grazing. Hay and grain are very low in moisture, causing horses to drink more water to meet their needs.
Hot weather also increases horses’ need for salt, because they lose the mineral during sweating. Consider adding a few ounces of salt or an electrolyte supplements to horses’ diets if lack of water consumption is a concern.
The most obvious sign of heat stress in poultry is panting. Here’s what to do:
Make sure birds have cool, clean water, and consider adding electrolytes. Feed birds during cooler parts of the day, and since birds produce heat while they digest, for broilers and turkeys, remove feed 6 hours before the afternoon peak temperature. Once the peak temperature has passed, feed can be reintroduced.
Make sure the birds have plenty of space, and make sure housing is well-ventilated.
7 Farm Dogs
And don’t forget your farm dog this summer. Give him a shady and well-ventilated spot outdoors, or even put a small kiddie pool in the yard and keep it filled.
Sources: American Association of Equine Practitioners; University of Kentucky College of Agriculture, Food and Environment; Michigan State University Extension; Penn State University Extension.
(Farm and Dairy is featuring a series of “101” columns throughout the year to help young and beginning farmers master farm living. From finances to management to machinery repair and animal care, farmers do it all.)