When it comes to bedded pack barns there’s a lot to love and some things to manage; and the rewards can be impressive in terms of cow comfort, production and longevity.
Ask Dr. Jeffrey Bewley of Alltech for his list of top considerations in bedded pack housing systems, and you will find “don’t overstock” listed twice. It is that important.
According to the University of Kentucky publication “Compost Bedded Pack Barn Design: Features and Management Considerations” – the compost bedded pack barn is a housing system that consists of a large open resting area, usually bedded with sawdust or dry, fine wood shavings and manure that is composted into place and mechanically stirred on a regular basis.
There is increased interest in compost bedded pack barn systems because of the potential for positive impacts on milk production and cow health, and the ability to handle manure as dry material.
Producer-reported benefits include:
- improved cow comfort,
- improved cow cleanliness,
- low maintenance,
- improved feet and legs,
- decreased somatic cell count,
- increased heat detection,
- ease of manure handling,
- increased production,
- increased longevity,
- low investment costs,
- less odor,
- fewer flies,
- less concern with cow size and
- improved manure value to the cropping operation.
The most critical success factor for managing this housing system is to provide comfortable, dry resting surfaces for cows at all times. Success requires getting a few things very right:
- Build the barn right to maximize ventilation.
- Stir the pack twice daily.
- Monitor the temperature of the pack.
- Don’t overstock the barn.
Lynn Royer of Blossomelle Holstein Farm, Elizabethtown, Pennsylvania, has learned quite a bit about compost bedded pack barns over the past 20 years. At his dairy herd’s previous location, Royer had a bedded pack pen ever since 1995. When relocating in 2005, he used a bedded pack pen connected to the freestall barn they built at their current location.
Royer likes this housing system so well — as an alternative for some of the cows all the time and all of the cows some of the time — that he built a bedded pack barn in 2007 to accommodate cow flow in Blossomelle’s second wave of expansion. The 265-cow dairy herd is housed in both the freestall barn with a bedded pack area, plus the newer bedded pack barn that is used mainly for cows during the month of pre- and post-calving transition.
“Older cows do really well on the bedded pack,” Royer observes. The environment is more forgiving. He sees the added benefit of the heat from the compost pack as being therapeutic to joints and muscles.
Sawdust is the main bedding material, but Royer also uses dry horse manure and corn fodder to start a compost pack.
“The trick is to keep it dry enough to be heating all the time. We try to add enough dry material periodically to keep the heating process going,” Royer explains. “A dry, clean bed is everything. If we have a cow with a sore foot or a cow that seems to be getting behind or having an issue, she goes to the pack. It’s a nice break, and the cows love it.
“As herds grow, I think we’ll see more pack barns as part of housing systems and cow comfort strategies,” Royer adds.
To achieve a good heating and a dry surface, Royer stresses that, “Cultivation of the pack is important, especially in the summer. We use the Farmall tractor and 3-point-hitch cultivator, instead of a tiller, because we’ve found it creates more heat to stir the compost pack this way – to get it dry enough to heat well.”
The Blossomelle Holstein herd is managed for an SCC average of 150,000.
Stirring the pack is important because the general concept of composting is to mix a carbon source (bedding such as sawdust) with organic material that is high in nitrogen (manure/urine), while providing porous conditions that introduce air into the pack to maintain the moisture level that achieves a rapid breakdown of organic matter.
This is one reason why good ventilation in the barn design is essential. Ventilation keeps the air drier to facilitate keeping the pack dry for good heating.
Dr. Bewley notes that, “keeping the top layer of the bedding dry is the most important part of managing a compost bedded pack barn.”
By properly composting through tillage or cultivating, the bedding temperature is managed for good heating or curing of the pack so that moisture is decreased. Deep stirring should be accomplished at least twice a day while the cows are being milked, using cultivators or roto-tillers.
The timely addition of fresh, dry bedding is also important because a poorly managed bedded pack can lead to dirty cows, elevated somatic cell counts and increased mastitis infections.
At Clover Patch Dairy, Millersburg, Ohio, Alan Kozak utilizes a drive-through compost bedded pack “We Cover” facility he built in 2007 to house 150 of his 400 milk cows in the winter months and to feed TMR to the herd during grazing season.
Kozak also beds with sawdust and tills his pack twice a day. The facility is designed with four-foot sidewalls and fabric curtained end walls to allow maximum natural ventilation, which he says is the key to keeping bedding surfaces clean and dry.
The Clover Patch Jersey herd is managed for high quality milk with SCC averaging 110,000. Cows rotate randomly between the freestall barn and the bedded pack barn – giving all cows opportunities to get off the concrete even during winter when they aren’t grazing.
In addition to facility design, site selection is critical. According to University of Kentucky publications authored by Bewley and former colleagues, compost bedded pack barns should be sited so that they can take advantage of prevailing summer winds and sun for drying. Care should also be taken to keep the barn at least 100 feet away from other facilities and silos on the farm that could interrupt or restrict this natural air flow.
“Barn ventilation must allow for fresh air, since the composting pack generates additional heat and moisture that must escape from the barn,” the University of Kentucky authors noted. “This is especially important in the summer.”
The building site of a bedded pack barn should be elevated slightly so the exterior surface drainage diverts around and away from the building to keep runoff out of the pack. The optimum moisture content is 45 to 55%, and pack temperatures should also be monitored to be sure the pack is still hearing.
All four sides of the barn should be 2- to 4-foot walls, including a wall to separate the bedded pack from the feed alley, which is helpful in managing the pack moisture.
The retaining wall keeps bedding material in the barn and can be poured concrete or moveable panels. Some setups use wooden panels or highway guardrail, and consideration must be given to the pressure from running wheeled equipment on the pack during tillage, as this will increase the pressure on the walls, particularly as the compost depth rises.
Pack barns are popular in Kentucky. In the Glasgow, Kentucky area, Crist Dairy is one example. Bill Crist is proud to say that his son Bill, Jr. is the first-generation dairy farmer, and he and his wife were drawn in as the second generation. “We’re a reverse generation deal,” says Bill, Sr. “Our son developed a passion for dairy and bought a herd and leased a farm before buying this farm and growing the dairy.”
Today, 550 cows are milked with a 3x RHA of 27,000 pounds. Dry and prefresh cattle are housed in a compost bedded pack barn built in 2016. The Crists farm 550 acres of mostly corn silage with haylage and ryelage in the forage base.
“We like the bedded pack for cow comfort,” said Bill, Jr., noting they add shavings twice a week in winter and once a week in the spring and summer, depending upon humidity levels. They till the pack twice a day year-round.
Back at Clover Patch Dairy in Northeast Ohio, Kozak uses a chisel to “turn” his bedded pack during two of the three daily milkings; and he cleans it out completely twice a year – using the dry and manageable composted manure on pastures and crop fields that need organic matter.
“Between cleanouts, we add sawdust at times of high heat and humidity,” Kozak explains, adding that his bedded pack sits on a clay bottom, not concrete. “The clay floor allows us to have the floor two feet below where the cows stand at the feedbunks. We can get our bedded pack to four-feet deep and still have room for the pack to expand.”
He considers the barn a worthwhile investment even on rented land because it allowed for good cow flow in expansion while improving herd health at the same time. “The cows just love it in here,” says Kozak.
Modified hoop structures can also be used for compost barn housing.
The concrete feed alleys in any designed bedded pack barn should be 14 to 16 feet wide with multiple points of access from the feed alley to the bedded pack so cows distribute themselves more efficiently throughout the resting area.
Good distribution of cows throughout the resting area helps to prevent wet, dirty areas from developing at a single point of entry due to the volume of cow traffic.
Placement of waterers is another consideration. Alley-only access is suggested to help minimize excess moisture in the pack and to keep water cleaner as well.
To size the pack area, experts suggest providing at least 100 square feet of resting space per cow (85 sq. ft. for Jerseys) and to increase this by 10 square feet for each 25 pounds per day of milk production above 50 pounds/cow/day due to the additional manure and urine production of cows that are consuming more feed and water for higher milk production.
In addition to adequate natural ventilation to handle the escape of moist air and the introduction of fresh dry air to the pack, mechanical ventilation may be necessary to prevent stagnant areas.
Facility specifications for overhangs, ridge vents, sidewall curtains, east/west orientation, roof pitch and other engineering considerations are important to improve the management and results of compost bedded pack housing systems.
While these housing systems are good for small herds and cohort groups of cows, Royer sees the compost bedded pack system as something most every expanding dairy could utilize to manage their transitional cow flow and cow groups throughout stages of life and lactation.
“Our cows love the bedded pack, and they all get on it at least one month during transition and calving,” he says. “We also use it to house certain cows full-time and to place cows that need a vacation from the concrete freestall barn.”
— By Sherry Bunting, portions previously published in Farmshine, KDDC Milk Matters and Progressive Dairy
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