"I could keep my calf hutches, or I could keep my wife."
It’s a sentiment that Ken Nordlund has heard more than once from the dairy producers he advises. Now, there is a workable solution.
Nordlund, who is a clinical professor in the Food Animal Production Medicine group at the University of Wisconsin-Madison, says the brutal winters of the Upper Midwest have motivated some producers to seek alternative housing facilities for their calves. “They want an option that offers the environmental and health benefits of hutch housing, with easier maintenance and better working conditions for those who care for the calves,” says Nordlund.
The result is a variety of configurations of “mini” calf barns, constructed of steel over a wood frame and often arranged in clusters of four to six units, usually sized to house 20 or more calves.
A worker-friendly alternative
Dan Smits, partner at Double S Dairy in Markesan, Wis., made the switch from hutches on his 1,200-cow operation three years ago. “I’ve got nothing against hutches in terms of successfully raising calves,” says Smits. “They served us well for years, and many people do a great job with them. We just wanted something that was less labor-intensive and easier to manage in the winter.”
Smits and his brother, Steve, transitioned from 160 hutches to four, single-row, 20-by-160-foot calf barns that house 45 calves each in individual pens. A deep gravel base saved on construction cost and reduces bedding needs, and a drive-through feed alley makes it easy to fill pails with pasteurized waste milk transported via a farm utility vehicle.
Curtained sidewalls open to the south, a feature that was a priority for Smits. The north sides also have 5-foot curtains that extend to 2-foot base walls. Both the east and west ends open with standard, 8-foot-wide garage doors, but Smits says they intentionally put automatic door openers only on the west end. “This requires us to back out after we fill pails, so we can observe the health and behavior of every calf at feeding time,” says Smits.
Quality time with the calves
Moving away from hutches is not the only reason producers are adopting the new style of buildings. Evansville, Wis., dairyman Mike Larson says he and his family partners at Larson Acres, Inc. opted for the small buildings when they expanded to 2,400 cows in 2010. They previously raised their calves in a large, 120-stall barn that still is in use.
“We liked the option of completely emptying and disinfecting the buildings between batches of calves,” says Larson. “And compared to hutches, this design allows us to spend quality time caring for the calves, regardless of the weather.”
The Larsons constructed four, double-row barns that feature curtained sidewalls and concrete floors, with two floor drains per side. Each side holds 30 individual calf pens. When calves are taken off milk at seven weeks of age, half of the pen dividers are pulled, so calves are weaned in groups of two to promote socialization. They exit the buildings at eight weeks of age.
Larson says the building configuration makes three-time-a-day feeding of fortified pasteurized waste milk an easy job, and he credits the practice with excellent calf health and performance.
“All-in, all-out” — a term borrowed from the swine industry — often is used to describe these new buildings. In most cases, it’s not quite true. That’s because even the largest dairies do not have enough daily calvings to completely fill a single barn. But the buildings do offer a key benefit of the all-in, all-out concept — the ability to “rest” empty buildings between housings.
When a building is emptied of weaned calves, all pen panels can be pulled for easy clean-out with a skid-steer loader. At both the Smits and Larson dairies, the interiors and all of the pen dividers then are power-washed and allowed to sit idle for at least a week. “In our large, original calf barn, we never are able to get the entire building emptied out at one time,” says Larson. “And compared to hutches, the clean-out of the mini barns is much easier. Two guys can scoop out, wash and re-assemble a building in less than two full work days.”
Because the buildings are not heated, water does freeze inside in the winter, which requires the same vigilance in water feeding as is needed with hutches. But Larson estimates that the interior of the buildings is 10 to 15 degrees F warmer in the most extreme winter conditions compared to the outdoors.
The Larsons bed with straw year-around. The Smits’ use straw in the winter and sand in the summer, and also use calf jackets in the winter.
In the three years both dairymen have been using the buildings, health and performance of calves have been excellent. Both dairies have maintained the 1-to-3-percent or lower death loss that they were achieving in their previous housing situations. “We have not sacrificed anything in calf health by moving into these buildings,” says Smits. He and Larson both say that, with some minor adjustments, their buildings could be adapted to group housing with auto or group feeders.
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.
One critical factor for the uniform distribution of air from the tube is to size the tube according to its air handling capacity, not just its measurement in inches. Nordlund says a common mistake is to choose an equal match between the tube size and the fan — for example, a 14-inch tube and a 14-inch fan. “Technically, we size the tube so that air speed inside is held to under 1,200 feet per minute, but a reasonable thumb rule is that the diameter of the tube should be about 1.25 times the fan,” says Nordlund.
The University of Wisconsin offers training on designing positive pressure, tube ventilation systems through The Dairyland Initiative, http://thedairylandinitiative. vetmed.wisc.edu/. Nordlund strongly recommends working with a builder or other professional who has completed this training.
More information from Nordlund on the ventilation systems can be found at http://www.ansci.cornell. edu/prodairy/calfsystems/proceedings/2.Nordlund. Manuscript.pdf.