In 1998, Mike Zeinstra built what was then a state-of-the-art, cost-effective freestall barn.
It had six rows of stalls, a fully-insulated ceiling and pitched, chimney-like ridge ventilation that ran down the center of the barn. The 46" stalls were 14'6" head to head. In 2008, they were converted from mattresses to sand, with manure scraped to a center, water-flushed flume where sand was reclaimed through a sand lane.
Fast forward 16 years and some eight cow generations later, and the barn is no longer so state of the art. Mature cows that were 1,300 lb. to 1,400 lb. in 1998 now easily top the scale at 1,500 lb. or more. Open side walls and ridge ventilation often don’t provide the kind of air exchange and cooling that these mature cows need when they are producing more than 100 lb. of milk per day.
This past year, Zeinstra decided it was time for a new facility for his mature, second-lactation and older cows. The result is a simple, straight-forward tunnel-ventilated barn that provides better cow comfort.
Zeinstra operates a 700-cow dairy with his wife Lisa, his daughter Ashley, and his son-in-law Justin Hoheisel, who is also a licensed electrician. The facility is located a couple miles north of Holland in southwest Minnesota. It’s only about 10 miles from the South Dakota state line and some 40 miles north of Iowa.
This corner of Minnesota’s rolling prairie sees every kind of weather—from scorching August sun to blizzards so deadly the pioneers used ropes to guide them from house to the barn and back again.
Dairy facilities, consequently, have to be designed to function in all of these conditions.
Zeinstra’s new barn does just that. The 106'x382' building is oriented east to west, with two rows of 51" fans, 28 in total, covering the east end wall. The sidewalls are just 12' high, and the peak of the building is just 14' to ensure air flow is concentrated over the cows. The ventilation system is designed to produce a maximum air speed of 9 mph down the length of the barn. On the west end of the barn, the air inlet side, two rows of curtains are raised and lowered to provide air intake based on temperature.
The ventilation system, monitored and controlled by computers, starts with six temperature probes strategically placed in the barn. The tunnel-ventilation fans start operation when the air temperature in the building reaches 40°F. Four of the fans kick in at 40°F, another four will start as the temperature rises 4° and so on until all 28 fans are running.
“These fans are most efficient on low speed, and so they will all come on and operate on low before they switch over to high,” Zeinstra says. “At 65°F, they’re in full tunnel mode, and everything is open.”
At temperatures below 40°F, the barn has side vents to allow air to come in under the eaves. The air escapes through eight roof vents positioned along the ridge down the length of the building.
This type of ventilation ensures air exchange is occurring throughout the building, even on the coldest days.
The barn has just two pens, with two rows of freestalls in each. The north pen has 136 stalls and 156 headlocks. It’s designated for mature, pregnant cows. Once cows enter, they remain in the pen until dry-off.
The south pen has 128 stalls and 156 headlocks. Mature cows, second lactation and older, are moved to the pen about 30 days after calving, are bred and remain there until confirmed pregnant.
The whole point of the new facility is to optimize cow comfort. So in both pens, Zeinstra tries to maintain one cow per stall. That ensures each cow has a bed to call her own, and there is plenty of open spaces at the bunk when she wants to eat. The 6'-wide rubber mats also provide feet and leg cushioned comfort down the lengths of the feed bunks.
Each pen also has three waterers. The south pen, which is housing cows as they peak in lactation, has 7½" of watering space per cow. The north pen, which houses the later-lactation cows, has 5" of waterer space per cow.
All the freestalls are 50" wide for the big-bodied Holsteins and Montbeliarde–Holstein crossbreds. (About a third of the herd is crossbred, involving Holstein, Montbeliarde and Scandinavian Red genetics.) The head-to-head stalls are 17" in total length.
Manure is removed with a mechanical scraper, scraping alleys 12 times a day. The barn also drops 18" over the length of the barn east to west to aid the scrapers.
One last innovation is a Juno robotic feed pusher. The Zeinstras feed just once per day, but the robotic feed pusher pushes up feed hourly. The unit was working so well, Zeinstra has installed a second unit in his older freestall barn.
The older, six-row barn built in 1998 provided a cheaper footprint for the building. But smaller stalls and denser cow numbers compromised comfort and ventilation in the summer. Although it was a nice
barn to work in during the winter months, cows simply did not perform as well as they could through the heat of the summer.
“We always had a dip in pregnancy rates in July and August in the old barn,” Zeinstra says. In the old barn, pregnancy rates hovered at 20% to 21% during most of the year, but dipped in summer.
“In the new barn, we’re at a 23% preg rate year-round and we’ve haven’t seen a drop this summer. We’ve never been that high for an entire year,” he says.
Plus, cows are now much more persistent in milk production throughout their lactations. “Production and reproduction are all benchmarks on how well we’re doing,” Zeinstra says`.
It appears, after about a year in, the new barn is acing those tests.