As with nearly any construction project, Smits says there are a few things he would change if he was starting from scratch. “We would make the drive-through doors 9 feet wide instead of 8, and I’d like to be able to drop our north curtains a little lower to cover a solar front in the summer,” he notes. “And we would build them further apart than the approximately 40 feet of spacing we have between them. We’ve found that because of their current placement, the air moves a little differently through each one.”
Nordlund notes there is a substantially higher investment in these barns compared to hutches, but labor costs are reduced at the same time. There also will be advantages to the barns that are real, but difficult to measure. “The more consistent environment should make it easier for early detection of calves that need attention — something that suffers badly in hutches on windy and miserable days,” he says. “The improved working conditions also should improve morale of employees and reduce turnover of people. And if that person is your wife, reduced turnover rate of people becomes a very big deal!”
“These buildings can provide excellent calf housing while offering a lot of flexibility in design and construction features to producers,” Nordlund continues. “I think we will see a lot more of them dotting the countryside in the near future.”
Ventilation is key
Excellent ventilation is a built-in feature of calf hutches, and often a challenge in larger calf barns. Central to the design of the new, mini-barns is supplementing natural ventilation with a positive-pressure, tube ventilation system that has been extensively researched by Ken Nordlund and his colleagues at the University of Wisconsin-Madison in recent years.
The system consists of a suspended ventilation tube — constructed of a plastic or fabric duct — connected to a fan and fitted with discharge holes along the length of the tube to distribute fresh air evenly. The holes must be custom-designed so that the discharged air reaches the vicinity of the calf, but does not create a chilling draft. The fan draws 100 percent of its air from outside of the building. Nordlund says the goal of the system is to positively affect the micro-area around the calf, which can be especially challenging when calf pens are divided with solid panels.
Nordlund cautions that precise calculations for the tube size, fan size, air speed, and size and placement of holes all are important to making the systems work effectively. For fan capacity, he and his team use a target of four interior volume changes per hour through the tubes to supplement the naturally ventilated barns.