Hazy, Hot, and Humid!!

Summer has officially arrived, and with it the heat and humidity. As uncomfortable as these hot days can be for us cows are even more miserable. Farmers do all they can to make the cows comfortable, but you can’t air condition the outdoors.

Dairy cows are most comfortable between 41oF and 77oF, but obviously if the humidity is high even lower temperatures can become uncomfortable. When cows get too hot and uncomfortable they eat less, which leads to less milk production. For example, increasing the temperature from 68oF to 86oF can reduce milk production by almost 10 lbs. One a 100-cow dairy that would equate to 1000 lbs less milk per day and with the current milk price of around $15 per hundred pounds that would equate to $150 in lost profit to the dairy producer each day just from the heat!

Due to the significant production losses that can be seen with heat stress in cows, farmers do lot a try to keep their cows cool. The most obvious is to provide plenty of water. Milk is 87% water so even in cooler weather cows need at least 20 to 25 gallons of water a day, but in hot weather they will drink up to 30 to 35 gallons. Of course, this water has to be provided in enough areas so cows don’t have to stand in line for water, and it should be provided in clean waterers. Cows on pasture are very susceptible to heat stress because they are more exposed to the heat so making sure they have enough water is even more crucial.

Shade is the other thing we think of as a way to cool down. Cows that are housed in barns already have shade available, but cows on pasture need a tree or some type of shade to stay cool. Many farms try to provide shade to their cows, but it is not always possible to provide shade on the pasture. Therefore, many farmers, who graze their cows, will bring them into the barn during the hottest part of the day to provide some relief from the sun and heat.
Fans are another option used on farms to keep cows cool. Almost all barns have fans in the main stall area, holding areas, and the milking parlor. Fans help move the air over the cows and evaporates the heat. There a many types of fans used on farms and one type, tunnel ventilation, you can see from the road. These farms have fans at one end of the barn and an opening at the other end, which allows the fans to pull air through the barn cooling the cows in the process. Also, there are fans in the barn itself directly over the cows that helps move the air even more.

Fans are a great way to cool cows, but adding sprinklers on top of using the fans is even better. Sprinklers are usually set on timers so that they come on every few minutes during hot weather. They are placed over the feeding areas so as not to get the bedding area wet. Sprinklers cool cows, much as running through a sprinkler cools you. When cows eat they get wet from the sprinkler and then the air movement from the fans evaporates the heat from the cow even faster than fans alone.