The demands of dairy

The movement from modest stanchion and tie-stall barns to large, open freestall facilities over the past three or four decades represents more than just a change of building styles. The rise of the freestall barn is only the most visible aspect of a transformation in the culture of dairying. In the past few decades, small operations based on family labor have given way to professionally managed businesses with a wage-earning, clock-punching work forces. Grass-eating cows, sometimes even with names, have been replaced by confined, computer-monitored animals that produce staggering amounts of milk for a few years, then are culled. Many of the wood-sided gambrel barns scattered across the rural landscape lie abandoned in favor of massive facilities that efficiently convert protein-rich feed into milk and manure.
The freestall revolution has been driven by new feeds, dairy parlor technology, cow comfort research, computerized herd management techniques, and milk prices that have created an unrelenting pressure to lower production costs — as well as by the lifestyle aspirations and values of a younger generation of dairy operators.
Like any revolution, the freestall movement involves gains and losses. Nostalgia may be on the side of the small operations, but the economics of milk production sure aren’t. Many northern tier states have been losing four dairy farms per day for several decades. Smaller stanchion and tie-stall operations may not be doomed yet, but their heyday is definitely past.
Luckily for builders, the move to freestalls also involves a lot of new and very large farm structures. Thousands of freestall barns, ranging from 200 to 2,000 cows, have been built since the 1970s. Rising milk prices made for a booming building market in the 1990s, and low interest rates have kept builders busy expanding existing facilities despite the low prices. Most contractors contacted by Rural Builder noted a softer market for dairy facilities in the past year. Some worry that a rise in interest rates could sink a lot of dairies with high debt loads.
Still, the freestall boom isn’t over yet. There are many areas of the country with large concentrations of smaller stanchion and tie-stall barns. University of Wisconsin Extension professor David Kammel says small barns still make up the majority of his state’s dairies — meaning there’s still a lot of potential freestall customers out there. Most builders were optimistic that milk prices would rebound, and the building with it.
But it’s not all about milk prices. While corporations have taken control of much of the West Coast dairy business, elsewhere in the country freestall operations are mostly built by longtime dairy families that have reached the point of generational change. Often it’s a family with two or more children wanting to take over, says Phil Martin, of Fingerlakes Construction in western New York, and they realize they have to get big to support more than one family. Others just see the economic forces at work. “They see what happened to poultry and hogs, and say ‘I’ve got to get myself big,’” says Ken Ramsay, design engineer at Lester Building Systems’ Charleston, Ill. regional center.
Freestall barn design has evolved over the decades. Eave heights have risen as the overriding importance of ventilation became clear. Alleys have widened, with automated systems such as feed conveyors giving way to drive alleys for trucks mounted with TMR (total mixed ration) mixers. Optimal cow bed dimensions have changed, prompted by research conducted by universities and consultants. Scrape and flush manure systems have been perfected, flooring types investigated, and bedding material tested.
Despite four decades of constant tinkering and experimentation, there’s still a great deal of variation in how dairies are laid out, built, and finished off. “You look at hog building, and they’re almost all the same width, the same column location, very standardized,” says Ramsay. “With dairy, you’ve got many different building widths, depending on the number of rows and the farmer’s preference for alley and stall spacing. Even those with the same width, the column locations are different.”
In designing their dairies, says Ramsay, “Farmers tend to look at a lot of buildings, and they know what they want. They tour around, and make lists of what they think works.” Low milk prices force farmers to view everything in terms of production costs. While freestall barns are relatively simple structures, their size makes every decision critical; a simple condensation blanket in a big barn can run $35,000.
But dairy operators are also a notoriously independent lot, and they often stick to their own ideas and resist standardization. “Farmers are constantly modifying their facilities, constantly fine-tuning things,” says Dean Widrick of Widrick Construction, Adams Center, N.Y.
Most builders can accommodate whatever details a dairy operator or consultant wants, within reason. But most also have an opinion on what works and what doesn’t. Rural Builder asked a handful of dairy builders their views on some of the more important of these details.

Rafters vs. trusses
Common trusses are inexpensive and create long clearspans that offer maximum interior flexibility. But many, if not most modern freestall barns are constructed not with trusses but with rafters, usually laminated veneer lumber (LVL) but sometimes engineered I-joists, glulams, or steel beams. They are supported by steel or wood columns, knee-braced at the perimeter (diaphragm design doesn’t work with the open end and side walls) with four interior columns set between alleys. Purlins are inset between rafters on draped hangars.
The idea behind the open rafter system is to reduce the locations where birds could perch or nest, thus improving the barn’s overall sanitation and minimizing bird droppings in feed aisles. Some believe it also facilitates air circulation in the barn. The system was introduced by Lester Buildings, and by all accounts has been both wildly popular with operators and widely imitated.
Rafter construction is more expensive, and not everyone thinks it’s worth the money. Martin, who’s sold freestall barns for 20 years, thinks the design’s primary appeal to dairymen is unrelated to its practicality. “The old farmers come out of their tie-stall barns, these cramped, dark dungeons, they’d go into a rafter barn and just be amazed by the openness, the height of them. They look great.”
As for their effect on birds, “They’re a waste of money, and don’t do a thing,” says Martin. “Truth is, if you’ve got birds on the farm, you’ll have them in the freestall; they’ll perch on the stalls, the head locks, anywhere.” Martin, whose 1,000-cow Danielewicz Dairy freestall expansion won 2002 Building of the Year honors from the National Frame Builders Association, generally uses a three-part roof, with a central truss and rafters along the sides.
Tom Jackson, who sells Wick Buildings in southern Wisconsin, agrees. He sticks to traditional trusses in the center of freestalls, with either LVL rafters or parallel-cord trusses at sides, and has no reports of bird problems. “Microlams are expensive for my area, and hard to justify,” he says. His customers appreciate the interior flexibility for alleys and stall layout. And if bird problems arise, says Jackson, the farmer can always retrofit products such as Birdblox or netting.
Still, birds are a serious nuisance for many dairymen, and most accept the notion that minimizing perches is worth the extra money — sometimes a lot of extra money.
Lakeside Systems in New Holstein, Wis., has used a third option: a solid arched truss, made by Starwood Rafters, that combines glulam, plywood, and dimensional lumber. The design offers a wide clearspan with no nesting and very limited perching spots for birds.
Other options include steel I-beam rafters, often used with wood purlins, and even standard pre-engineered steel building trusses. While a few dairies are choosing metal buildings, it’s generally an expensive option, says Widrick. If freestall barn widths increase, however, expect to see a lot more steel structurals.

Insulation
Insulation is a hotly debated topic in dairy barns. Stanchion barns are kept relatively warm for the benefit of the workers tending and milking the cows; the cows, however, do just fine with the wide temperature ranges that nature affords. The emphasis on ambient temperatures and ventilation is one of the chief characteristics of freestall barns, which are essentially shaded windbreaks.
Insulation, of course, is generally used in milking parlors, again for worker comfort. Holding areas leading to the parlor are usually partly insulated to moderate heat loss from the parlor. But in freestall areas, experts urge producers to allow ambient temperatures to prevail: “Any attempt to temper barn air so that it is more than 5 degrees C warmer than outside conditions has been shown to result in poor air quality,” says Cornell University ag engineer Curt Gooch.
“The benefits of insulation are minimal, the presence of insulation in a building may lead to mismanagement, and the initial cost of insulation can raise the cost of the building significantly,” Gooch said at a recent freestall conference. “The extra cost associated with purchasing and installing insulation does not affect cow performance; therefore, producers are advised to use capital funds to install fans and evaporative cooling equipment, as this will benefit the cows during heat stress conditions.”
So much for expert opinion; many dairymen ignore the advice. Insulated barns are still common in the Dakotas, says Ramsay. Mark Mashlan of Fox Structures in Kaukauna, Wis., says he uses insulation in about half his dairies; Larry Speitz of Valley Building Systems in Little Chute, Wis. insulates three-fourths of his.
The materials most often used aren’t very insulative, of course: usually a 2-inch or less laminated fiberglass blanket, or a rigid polyisocyanurate board. Speitz has also used foil-faced reflective insulation on occasion.
The primary motivation for insulating barns is to lessen cool-weather condensation, which creates indoor rain and can lead to roof panel corrosion. Other reasons include moderating temperatures for worker comfort; preventing manure from freezing in alleys; and minimizing peak temperatures that can cause heat stress and lower cow productivity.
Gooch believes proper ventilation is the better answer to condensation problems and heat build-up, and suggests flooring solutions for manure freeze. There are two additional concerns with insulation: birds can wreck some insulations and use it for nesting. And rigid insulation, says Ramsay, can interfere with the transfer of design loads from roofing to purlins by creating a gap that a fastener must bridge.
Lakeside’s Steffes still recommends an insulated condensation barrier in his freestalls. “One guy didn’t want it, and the next year we were back pulling off the roof to retrofit the material. They couldn’t take the constant dripping.”
Some farmers even want full insulation. On one of Steffes’ projects, 6-inch fiberglass batts were inserted between purlins, with a PVC panel screwed in place to form a slick ceiling. “That place stays in the 40s when it’s below zero,” he says.
Whether insulation will ever pay for itself, whether in cow productivity or by protecting the steel from corrosion, is a different matter.

Ventilation
Most modern freestalls use open ridge ventilation, with the gap fitted with poultry netting to keep out birds. The rafters or trusses must be flashed or otherwise protected where exposed to the weather. The open ridge is usually centered over the drive alley, and so is often not appropriate for a barn with an odd number of rows.
Overshot ridges are a bit more expensive, and seem to be a regional or even local variation. They usually have a short upstand on the low side to lessen snow intrusion, or a curtain that can be closed. Overshots should be oriented away from prevailing winds, however, as one builder learned the hard way one snowy winter.
Holding areas often have ridge vents with caps to prevent the entry of snow and rain. Valley Building hangs a 12-inch PVC pipe that can be raised up in frigid weather to loosely close off the vent.
Continuous raised ridges are often used to increase the drafting force on ridge vents. Chimneys can also be used to accelerate ventilation.
The latest trend, still rare, is to eliminate ridge vents entirely and set up fans to induce tunnel ventilation: an old stanchion barn technique reinvented for the freestall.

Footings and columns
Most freestall barns are still built with traditional post-frame embedded columns at their perimeters, offering a strong connection to transfer design loads. A lot of builders, however, are turning to perimeter concrete footing walls, set on piers, that can be incorporated into the stall design.
Interior columns are often steel; operators often want to be able to weld gates and other hardware in place, and steel also stands up well to the occasional smack from skid steer loaders in the feed alleys. Whether wood or steel, interior columns can be set on curbs that separate alleys, with footings incorporated into the curb design. In theory, this allows concrete work to be completed all at once, before the building contractor even arrives. Placing columns on raised footings also sidesteps some manure seepage concerns that some states are having, says Ramsay.
Builders should be aware that proper anchorage of columns is often neglected, says Ramsay, since it falls between tasks delegated to builder and concrete contractor.

Steel vs. aluminum roofs
Both galvanized steel (G90 is recommended) and aluminum are used for dairies. It is critical not to use Galvalume material for cattle and hog operations, particularly in cold climates, because the condensation can cause pitting corrosion.
Aluminum carries a higher price than steel, but stands up to moisture-induced corrosion much better, and should outlast steel. Some builders have seen steel rust out in less than a decade, and swear by the lighter material.
The downside to aluminum is its higher coefficient of expansion, about twice that of steel, which means that longer panels will put more stress on roofing fasteners. As a softer material, aluminum will more easily “slot” beneath the fastener, creating potential sources of leaks. According to Fabral’s Bill Croucher, through-fastened aluminum panels should therefore be limited to 16-foot lengths, with longer spans end lapped. Steel panels can be installed in lengths up to 40 feet.
The choice of metal is strongly regional. Nearly all Midwestern barns use painted steel, says Ramsay, while the preference for aluminum is strongest in New England, New York, and Pennsylvania. Like many other dairy features, the choice probably has more to do with a handful of regionally admired and imitated facilities than anything to do with the climate.

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