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Continually agitated manure system launches in North America

Irish-developed system installed in new Wellington County dairy barn

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In an innovative new dairy barn near Moorefield, the centuries-old practice of composting solid manure is being combined with a new-to-North-America approach to continually agitating liquid manure.

On May 12, Kristina and Simon Signer moved their 53 Brown Swiss from a tie-stall set-up in the Sigview Farms bank barn to a new composting bedded pack structure with one milking robot, and the built-in footprint for another robot once their quota holdings expand accordingly.

There’s enough space, based on the recognized standard of 120 square feet of bedded pack per head, to accommodate 100 cows.

There’s liquid manure collected from the feed alley portion of the barn, which is agitated by the new Dairypower system.

Why it matters: Toxic gases are a risk of only occasionally agitating liquid manure, and the Dairypower system eliminates that risk.

The Signers hosted a COVID-19-style barn tour in late August, with pre-registration necessary for a particular time slot, mandatory mask use, and a limited number of guests at a time.

Simon grew up on the farm with Brown Swiss in the herd, and he and Kristina have been happy to continue the tradition. “The health aspects, the ease of maintenance, the longevity” are all reasons why he loves the breed. Similarly, cow-health-related aspects were considered when they researched a move out of the tie-stalls. According to Kristina, they decided on the bedded pack because of cow comfort and simplicity of operation.

Kristina and Simon Signer are shown in their newly-constructed composted bedding pack barn. Sigview’s 53 Brown Swiss cows moved in from the old tie-stall bank barn on May 12. photo: Stew Slater

The pack was established by covering a layer of wood chips with sawdust. Since then, it has been cultivated daily to turn down the patties and incorporate them into the composting pack, and to bring wdrier material to the surface.

When things start to get a bit moist in spite of the cultivation, additional sawdust – delivered by truckload to a storage area conveniently located inside the barn adjacent to the pack – is spread over the area.

Between May and the Aug. 26 barn tour, the pack hadn’t built up much despite regular additions of new material. Naturally occurring microbes and other organisms have been hard at work during the heat of the summer. The Signers say they’re not sure how it will react as the weather turns colder, but they expect the pack may start to expand in depth as microbial activity slows.

For now though, one truckload of sawdust is lasting them more than a month. “The way it looks right now, it should cost less than what we were spending on straw in the tie stalls,” Simon notes.

The barn tour was hosted by Grand River Robotics. The Fergus-based company not only installed the Lely A5 milking robot, but also provided the farm’s new Lely Juno 100 automatic feed pusher and Lely Discovery robotic slat scraper.

“The cows have adjusted really well to the robot,” Simon said. There are very few that still need occasional fetching, and none that were so resistant that they had to be culled.

Simon believes the tunnel ventilation of the new barn plays a big role in keeping things dry, and the compost working, throughout the summer. He knows of another tunnel-ventilated pack barn in which the farmer has not added any new sawdust this summer.

At an average of 130,000 and a low of 75,000 since moving into the new barn, Sigview’s somatic cell count is slightly lower than the average in the tie-stall, and well below DFO’s threshold for warnings or penalties. This has eased concerns about one of the often-suggested drawbacks of bedded pack housing for dairy.

If you manage the pack right, Simon suggests, it’s possible to keep SCC in check.

Simon Signer credits the tunnel ventilation installed in the farm’s new pack barn for helping keep things dry over the summer, thereby decreasing the need for additional sawdust bedding. photo: Stew Slater

For the scrape alleys and the milking robot, meanwhile, Sigview opted for a new-to-North-America manure management system from Irish company Dairypower Equipment. Dairypower has been around since 1973, originally specializing in milking equipment but subsequently switching focus to manure handling and management. The Smart Manure Aeration System, which is now being marketed in North America after years of success in the U.K. and Europe, was first introduced into the Irish market in 1998.

“It’s certainly not a new idea, or a new system. The bugs are worked out,” said Dairypower’s business development manager for North America, Adam Steward. “But it is new to North America.” And, despite the name of the company, the system has been installed not just in dairy barns but also in barns housing beef cattle, poultry and hogs.

The unique system relies on pipes installed throughout the manure collection and storage chambers, on a grid in which air release valves are placed at regular intervals. Air is pumped into the system on a timer, coordinated with the opening of each valve in succession. Each valve across the entire grid releases air for one minute, three times per day.

This continual agitation means the manure is ready for use whenever the farmer needs it. Without a risk of hydrogen sulfide build-up from stagnant manure and/or crusting, there’s no need for agitation prior to handling or land application. And no risk during the agitation process for harmful hydrogen sulfide exposure or explosions due to excessive methane.

Similarly, the constant agitation results in reduced odour and release of chemicals associated with global warming — benefits both to the farmer and to the wider community.

Steward says the nutrient level of the resulting manure is also improved due to the absence of anaerobic conditions in the system. Without oxygen, significant nitrogen and even some potassium can be burned off instead of converted by microbes to forms that are useful for soil health and crop growth.

“The company has put in approximately 3,000 systems worldwide and, on the low end, the guys that have the systems are purchasing 25 per cent less nitrogen fertilizer. And there are a lot of them who have even better savings than that. It ranges up to 40 per cent.”

Dairypower installed a Smart Manure Aeration System at the Canada’s Outdoor Farm Show site, which can be seen in operation as part of the 2020 shows’ virtual Innovation Showcase. The system can be installed in either new or pre-existing manure storage facilities.

About the author


Stew Slater

Stew Slater operates a small dairy farm on 150 acres near St. Marys, Ont., and has been writing about rural and agricultural issues since 1999.



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