Odors are so minimal at a northern Iowa wean-to-finish barn that neighbors a half-mile away didn't even realize pigs were in the building for six months.
Father and son producers Don and Bert Huftalin built the 3,600-head facility three years ago with a mindset that considered return on investment rather than up-front costs. One place they didn't skimp was ventilation.
Their system, designed by the Danish company SKOV, was quite unlike any in the U.S. Totally mechanical, the system features computerized climate control through forced ventilation and high-pressure cooling that limits temperature fluctuations to a minimum, 24/7.
“The Danes know so much more about ventilation,” says Bert Huftalin, who also owns an 800-sow, farrow-to-finish operation with his dad near Malta, IL. Huftalin took time off from college and worked on a few European pig farms in the early '80s, and was always impressed with the air quality.
Pig concentration is much higher in densely populated countries like Denmark and the Netherlands, points out Marc van de Ven, SKOV export manager and an agricultural engineer. Barns are very close together, so farmers cannot afford to have air transmissions from one unit to another for disease reasons. Odor control is another issue because of the close neighbors. Most of the pig buildings are mechanically ventilated.
Huftalins' T-shaped facility is divided into three rooms of 1,200-head each. Temperatures in each room are preset according to growth phase and never fluctuate during the day; however, the room temperature does slowly ramp down in a linear curve over time.
If Day 7 temperatures are set at 85° F. for postweaned pigs, for example, and Day 14 temperatures are set at 80° F., the five-degree drop is achieved through increments of only 0.1 degrees about every three to four hours. In other words, the pigs don't feel a thing.
“The ventilation from minimum to maximum is absolutely linear. If ventilation is increased 1%, the rate of air going out of the building is increased 1%. It is a multi-step principle designed to save 60% of the energy consumed in a traditional system. That is the most important feature,” says van de Ven.
Basically, fans are always running in the most efficient position, he adds, and there are a minimal number of variable-speed fans, which van de Ven says are most inefficient. There are 10 chimney fans and four, 48-in. gable wall fans per room that serve as backup for the cooling system. Four of the chimney fans are directly connected to the 8-ft. pit.
Rooms are cooled by a 1,000 psi, high-pressure mister that adds humidity in the form of filtered, very-fine water droplets; van de Ven feels it is extremely important to avoid both too low and too high humidity levels for pigs. “The cooling system is equivalent to an evaporative cooler — something no one ever puts in finishing barns. It has paid for itself,” says Bert. “It is huge in rate of gain.”
Controlled air inlets are another critical component of the Danish system. “In our eyes, we cannot control ventilation if we have no control over incoming air,” continues van de Ven. “It is easy to get air out just by sticking in another fan. It is most important to make sure air coming in does not draft pigs and secondly, that air speed and air distribution at the animal level are always correct.”
Inlets are placed high on the 8-ft. sidewalls — something Huftalins' contractor struggled with during installation — and there are 144 of them. Rather than air dropping straight down on pigs along the outside wall, chilling them, it flows to the middle of the building to drop slowly and then circulate.
Draft is something the SKOV system avoids above all else, notes Henrik Bjaerge, worldwide service manager. He also notes that one computer controls the entire system. There are no thermostats.
Another SKOV feature that attracted Huftalin's attention was the water meter. “For $100 per room, the information generated is amazing,” says Bert. A computer graphic (Figure 1) indicates water consumption. The water-to-feed ratio, even if pigs are scouring, is very constant. If they eat 1 lb. of feed, they drink 2.2 lb. of water — slightly more in the summer. That makes it easy to track feed consumption, he points out.
That water:feed ratio is not nearly as accurate with nipple waterers or cups due to wastage, notes Marvin Wastell, GroMaster, Inc. of Omaha, NE. Wastell is the one who suggested SKOV to the Huftalins after seeing the systems in Denmark. His company sells the wet/dry feeders Huftalin uses. They are similar to those used by the Danes, which have zero water wastage, according to Wastell. Cup drinkers are used the first six to seven weeks after pigs arrive and then are turned off. The wet/dry feeders become the only water source.
The water meter raises red flags when something is wrong or something has happened, points out van de Ven.
Huftalin agrees. “If pigs get sick, water consumption drops and it usually shows up before they appear ill. It gives us a head start in treating sick pigs.”
Water intake is just one example of information the computer can spew. According to van de Ven, they can track every system setting and measurement in two-minute increments for the last three years at Huftalins' building. And they can do it from Denmark. Every three to four months he scans graphic printouts from the building and calls Huftalin to discuss any issues. Changes to the system can also be made from a remote location with a passcode.
Another important graph tracks temperature and humidity, notes the SKOV engineer, but there is more. SKOV provides technical service personnel to look deeper into system details for troubleshooting and fine-tuning.
Parameters of air flow, heating and humidity control are fine-tuned based on the graphs of data generated over time. Fluctuations and interactions between humidity and inside and outside temperature, for example, are scrutinized to make sure settings are still correct as climate conditions change.
There are thousands of SKOV systems around the world, says van de Ven, including at least 400 in Canada. Approximately 70% of the swine and 80% of the poultry operations in Denmark have the SKOV system.
He was hesitant to provide cost figures, because every system is designed for a particular building. In general, though, again depending on the size and type of building, a wean-to-finish project with the complete system (inlets, interlinking, exhaust, cooling, PC monitoring, remote access, computer) is between $30 and $40 per pig.
According to van de Ven, the company has been looking into the U.S. market the last four years. Other countries seem more willing to invest in sophisticated (higher investment) systems. “But the U.S. industry is slowly changing to optimize, instead of minimize, investment in facilities,” he says.
The Huftalins — Bert is a former Pork All-American — have a different philosophy. They spend more on a building than most people because they're in it for the long-term. “There is no question the SKOV system costs more than a tunnel-ventilated barn, but it pays for itself,” he notes.
Bert adds that it was an easier choice to install the Danish system because the building was new. “And we not only wanted a better environment for the pigs, but for the people — both inside and out. I told our vet that he would have to forget everything he knew about ventilation.”
Another problem with standard U.S. buildings from the Danish point of view is they are not tight. “If buildings are not tight, we cannot control air flow,” says van de Ven.
Finishing pigs at the Illinois site are raised in naturally ventilated, curtain-sided buildings that cost a lot to heat. If they could, Bert would convert those units to the SKOV system.
Death loss is lower at the Iowa site — about 3% for wean-to-finish — and rate of gain is better with fewer lightweight pigs. Medication costs are also less in the SKOV building than in Illinois. They no longer vaccinate for myco-plasma, for example. Yet pigs all come from the same sow source.
The SKOV system is really linked to production, says Norm Hogrefe, a distributor from Storm Lake, IA. “The producer is able to monitor production along with ventilation together through one system. It ties information together in real time.
“U.S. producers need to learn how to control ventilation,” he adds. “We have changed a lot of air in a lot of buildings, but ventilated very few.”