To start of our new Artex Connection: Dairy Expertise From Around The World blog, we've reached out to Ashley Ambrosius of Bayland Buildings in Greenbay, Wisconsin to share with us her 3 important considerations when looking to build natural ventilated freestall barns.
Ashley Ambrosius works in Agricultural Marketing and Customer Relations at Bayland Buildings in Greenbay, Wisconsin, USA. She's been with Bayland for 12 years, and has been in the agricultural construction field for 7 years.
The thought of building a new freestall barn is so exciting. This opens the door to unlimited opportunities to focus more on cow comfort. Here are a few pointers I can suggest when considering to make the most out of your new natural ventilated freestall barn in cold and temperate climates.
Utilize Mother Nature
Mother nature has so much to offer when it comes to ventilation. If you plan to build a natural ventilated freestall barn, you should capitalize on the natural breeze surrounding you. By positioning your barn in an orientation that ensures your barn will sit perpendicular to the prevailing wind. In turn, this will make it much easier to catch the breeze.
By placing your facility in this direction, you will also reduce the direct sunlight and will be able to capitalize on the natural shade of the building itself. Depending on the number of rows in the barn you are building, your stalls on the outside walls of the barn may never receive direct sunlight. It is also important to have adequate space between other structures when planning for your new barn’s placement.
Our rule of thumb is to space each barn at a minimum of 100’ apart. This will allow enough space for the wind flow to drop back down to the cow’s level after coming off the top of the neighboring barn.
Roof Pitch and Sidewall Heights
The roof pitch and sidewall heights are a crucial factor in a natural ventilated freestall barn. If these two factors are not correct, this will throw a loop in the whole idea of natural ventilation.
My suggested roof pitch in a natural vent barn is to stick with a 4/12. Roof pitches that are lower than a 4/12 will create slower air movement. With the air at a slower speed, warm moist air will be created and then the unwanted condensation will begin to form. A roof pitch that is steeper than a 4/12 will create a faster windspeed at the roof height and leave stale air at the cow’s level.
I suggest putting an overshoot ridge in a natural ventilated freestall barn because it will allow for a better-regulated air flow and controlled temperature in the winter months. Ideally, with a 4/12 and venting in the overshoot ridge, you are pulling air through the side walls at the cow’s level and allowing the air to circulate up through the ridge. A big bonus with the overshoot is you will eliminate snow and rain from the feed alley, allowing for a cleaner environment.
I suggest a minimum of 14’ sidewall height to get the most out of your natural ventilation. If your climate is cold enough to require curtains, they should be fully open in the summer months to maximize airflow. In spring and fall months the curtains should be open moderately depending on the ambient temperature in your facility, and in the winter months, the curtains should always be open partially.
The biggest mistake I see in the winter is people closing the curtains tight to eliminate a cold breeze. This is the worst thing you can do. You need to keep an even air exchange at all times to keep the moisture and condensation out of the barn. By not allowing the air to exchange from the moisture being put in the air from your animals, the bacteria will begin to grow.
When designing your new freestall barn, you should put a great deal of emphasis on the barn’s layout design. First and foremost, do not try to steal a few inches here and there to cut down the overall footprint of your barn. You ultimately are taking away from the comfort of the cows.
Be sure to leave adequate space to allow your animals to move freely throughout. Keep all overcrowding to an extremely low percent if it all. Overcrowding plays a large role in comfort and in the end, production. While laying out your barn design, be sure, to be honest with yourself about your numbers.
Allow for the stalls to have enough lunge space. When calculating stall sizes, keep in mind if a stall is on an exterior wall, the stall needs to be longer versus if it is a head-to-head stall. In a head to head layout, the cow can lunge into the opposite stall while getting up. In an exterior wall bed, she has nowhere to lunge into other than the wall. If this is the case, the cows will steer clear of resting in the exterior wall stalls.
Lastly, this one is very important in my book. Be sure to build in enough crossovers with watering stations. Generally, our rule of thumb is, for every 100’ of barn you should match up 3 crossovers. By placing a crossover on each end wall, you are eliminating any “dead ends” and allow a constant footprint flow.
Building a new barn is an investment in your future and the future of your business. It’s important to do your research before jumping in with two feet. There are so many small factors that can play a large role in the success of your operation.
So, finding a contractor that specializes in Agriculture is key. As is finding a contractor you are comfortable with and confident in. Don’t hesitate to ask questions and even talk to a few different contractors before you “start” the process.
Bayland Buildings Inc has been providing customers with seamless building experiences since 1991 and has a dedicated agricultural division and has become one of the most competitive and respected building firms in Wisconsin.