Dear Aggie

How do farmers keep their cows cool in the summer?

The summer heat can be enjoyable, but it can also be too hot to handle. In order to feel more comfortable, we seek shade, sit in front of a fan or hop in a pool to cool off. Believe it or not, like humans, cows cool down in a similar way. Farmers work very hard to ensure our bovine beauties don’t overheat with some pretty “cool” practices.

Farmers strive to provide the best comfort for their cattle; This way they can remain happy and healthy! Cattle are most content in cooler temperatures. Once the THI, temperature-humidity index, is higher than 68, cattle can experience heat stress. There are negative effects associated with heat stress on dairy cattle that affect their productivity and health. These cattle begin to experience decreased milk production, feed consumption and time laying down.

When cattle begin to experience the early stages of heat stress, they will seek shade, begin to sweat, breath faster, increase water consumption and eat less, in order to not ruminate and generate heat.Farmers use four methods to increase cow comfort and decrease heat stress on farms: shade, curtains, fans & sprinklers.

When cattle are in barns, farmers are able to control the cattle’s environment and shield them from extreme weather conditions. This protects them from the extreme heat and also prevents sunburn. For cattle on pasture, farmers can utilize smaller building structures like lean-to’s or trees to provide shade. Shade cloth is another great alternative for shading cattle. Farmers can adjust the temperature in their barns by raising or lowering curtains. This also regulates the amount of fresh air circulating through the barn.

Fans are commonly used on today’s farms for heat abatement. They come in a variety of styles and sizes to cater to all barn structures. Fans can be placed above the stalls where cattle lay to encourage the cattle to lay down during the hot months. Fans can also be installed to create a tunnel-ventilation system, which is an effective way of providing increased air exchange and high air velocity for improved hot weather cow comfort. A tunnel ventilation system can be installed in unobstructed rectangular barn layouts.

Sprinkler systems can be installed on farms to spray cool water on the cows’ backs. A “cool down effect” is created by the water evaporating off cows’ backs and removes heat energy from cows’ skin. Spray cooling works best as intermittent wetting and cooling/drying of cows’ skin for a better heat transfer from cow to the environment and lowers respiration rates to a stable level. Fans should be run continuously to reach this optimum threshold.

As you can see, farmers take extensive lengths to ensure their cows are well-cared for, especially during the heat. For more information on cooling systems for cattle or other dairy & livestock related questions, contact Gabby Wormuth, the Dairy & Livestock Specialist for Cornell Cooperative Extension of Jefferson & Lewis County at grw67@cornell.edu.