Cattle wear winter jacket all year round

Humans wear more or less clothing depending of the outdoor temperature. When it is cold outside we wear winter jackets and when it is summer people wear shorts and t-shirts. Now imagine you were a cow and were not able to take off your winter jacket during a warm summer day.

Do you think you would be able to work at your best on a warm summer day if you had to wear your winter jacket? Never the less, this is what we ask dairy cows to do.

From a historic point of view the highest level of production results are seen in countries with relative cold outdoor temperature. However today, the right climate system can reduce heat stress for dairy cows and secure a high level of productivity even when it is warm outdoors.

Cow signals

The cows are able to tell the farmers that they feel the temperature it to high.
The cows:

• Breathe more rapidly
• Drink up to double amount of water
• Stand more often and drool
• Eat less and become lazy
• Prefer to stay in the coolest areas of the barn

When the cows show signs that they are out of the comfort zone and feel heat stress, the farmers or dairy companies should be strongly interested in improving the climate system. Heat stress has tremendous negative impact on the production results.

• Milk production is reduced
• Negative impact on reproduction efficiency (fertilization, conception and pregnancy rate)
• Higher risk for infections

New results published in 2013 also show that heat stress during late gestation has effect on the calves and milk production.

When will heat stress occur?

The cow will feel it is too warm if the Thermal Humidity Index (THI) is greater than 68. Both ambient temperature and humidity are used to calculate the Thermal Humidity Index, and in the figure below a table is shown which can be used to evaluate whether the cows feel head stress or not.

Munters produce ventilation products for both natural ventilation and cross/tunnel ventilation for cattle. If you have a customer in an area where the cows have heat stress many hours during the year, do not hesitate to contact your local Munters sale person and ask for help to design the ventilation system so the cows will not get heat stress, but increase productivity. 

Read more about heat stress for dairy cows in these case studies:

• Solutions to dairy heat stress in Brazil