Barn Ventilation Priorities

( Mike Opperman )

Ever spend time in a building where there’s no air movement and humidity is high? It’s not fun. If humans don’t like it, cows don’t like it, either. 

There are a variety of barn styles housing cows on dairies across the country. “Design variation within a system can be as great as it is between systems,” says Nigel Cook, a professor in food animal production medicine at the University of Wisconsin School of Veterinary Medicine. Here are three priorities for all types of ventilation systems: 

1. Provide fresh air to the cow’s lying area. “We need to provide fast-moving air in the lying area in the summer and a gentle breeze in the winter,” Cook says. This can be achieved through the use of baffles or fans, or a combination of both. “Once we have provided fast moving air in the lying space, we can use natural or mechanical ventilation to displace contaminated stale air in the barn by bringing in fresh outside air.”

2. The system should work as well in the winter as it does in the summer. Cook says most mechanically ventilated barns are designed around summer ventilation. “We think it’s important that whatever the season, sufficient fresh air should be brought into the barn to ensure good respiratory health. A minimum ventilation rate for winter of four air changes per hour should be achieved,” Cook says. 

3. Do not assume faster moving air is better. Just because air is moving fast in one area of the barn doesn’t mean it’s benefiting cows in another area. Cook says some barns are designed for high air speeds in alleyways, but that doesn’t guarantee there is adequate air movement over cows. Regardless of the barn style, proper ventilation is an important part of cow comfort to ensure cows are in an environment that allows them to perform to their potential.