Animal comfort, health and productivity are enhanced, but management is key, and bedding cost and availability are limiting factors.
By Susan Harlow
Comfortable, healthy cows, less manure odor, excellent soil amendment, environmental benefits… What’s not to like about bedded packs?
Bedding cost and availability, that’s what. Composting bedded pack barns, which rely on sawdust rather than straw, may be particularly questionable now, when sawdust is locally expensive and hard to find.
In fact, the growth of composting barns has slowed in the Midwest because of bedding costs, said Marcia Endres of the University of Minnesota, who researches compost barns.
But in the Northeast, more hoop-style bedded packs are being built, especially by smaller producers looking for an alternative to covered barnyards. Government cost-share money for their environmental benefits also makes bedded packs attractive.
There are two types of bedded packs:
1) A deep bedded pack, most common in the Northeast where availability of sawdust is a constraint, has bedding added daily and is not turned or tilled.
2) A composting, or aerated pack, common in the Midwest, is tilled usually twice daily with a cultivator or rototiller.
Management is just as essential with a bedded pack system as for a freestall or tiestall barn. Poor management will negate any upside.
In a recent case study of a dairy with a bedded pack, Cornell University’s Department of Applied Economics and Management found the system offers “an excellent environment” for cattle and has environmental benefits, but said managing bedding costs is crucial to make it sustainable.
Larry Wilterdink of Waldo, Wis., goes through a semi-trailer load of sawdust once every three months in summer and once a month in winter to bed his 80-head composting bedded-pack barn. The price has risen in the three years since he built the barn – from $1,400 to $1,700/load.
“It doesn’t really scare me because I figure I’m making it up in cow health and not culling out cows,” Wilterdink said. The pack compost also gives him the benefit of excellent fertilizer, and a product to sell off-farm.
Wilterdink wanted cow comfort from his barn and he got it, along with odor control and healthier cows. “Cows last longer in the herd and breeding is better because heat detection is easier,” he said. It’s a good way to store manure as well, especially because his dairy, near a river, probably couldn’t be permitted for a liquid storage system.
Bedded pack barns offer these benefits:
• Manure management. Many producers turn to bedded packs to get away from liquid storage systems. The barns keep odors under control and used bedding can be spread on fields or composted.
• Cow comfort. Bedding depth, starting at about a foot, cushions cows. A recent study by the University of British Columbia found cows prefer bedded packs to freestalls when given the choice, and spend more time lying down and standing on packs.
• Herd health. Cows’ feet and legs do better on packs. Endres found less lameness, 6.5% in compost barns, compared to 17% in sand freestalls. Hock lesions were fewer, as well.
Cleaner udders can reduce milking prep time and mastitis. Studies in Wisconsin and Minnesota noted a drop in mastitis on bedded packs, although a recent study by Cornell University saw no change from freestalls.
“Management is more finicky than in a freestall, so if you don’t manage it right, you’ll have the same problems, only worse. You have to do it well to gain the benefits and avoid problems,” said Tom Gilbert, executive director of Highfields Institute, Hardwick, Vt., a nonprofit organization which promotes composting.
• Better reproduction. Heat detection can be improved by as much as 5%, Gilbert said, boosting pregnancy rates (PR) by as much as 3%. Endres’ study showed a 2% rise in PR, to 16.5%.
• Improved milk production. Cornell’s study found milk production rose 2,000 lbs. per cow, in part because of the bedded pack.
• Improved soils. Manure removed from a bedded pack and composted, then spread on fields, add significant organic matter and nutrients – eventually. “Composted material is very stable, so you don’t see much agronomic return in the first year,” Gilbert said.
Guy Choiniere, Sheldon, Vt., grazes his cows in summer, but makes sure they’re on their bedded pack full-time by mid-October. “They have a job to do between Oct. 15 and April 15, and that’s produce 800 tons of manure,” he said. After cleaning the barn – a job that takes him one day – Choiniere spreads some raw manure on his fields to maintain a diversity of feed for soil microorganisms, and piles the rest for the following spring.
Choiniere built the SuperStructure barn five years ago. At 7,200-square feet, the barn isn’t roomy enough for the 85-head milking herd and youngstock older than six months, which take up one-third of the barn. So in the winter, half the milking herd spends half the day in the tiestall and half in the hoop barn.
He’s impressed by the cow comfort and health, although his initial goal was environmental. “I put it in to take care of covered barnyard problem and so I wouldn’t have to enlarge my pit for more liquid manure,” he said.
That was Earl Fournier’s idea, too. His Cover-All fabric barn serves as a covered barnyard with plenty of light. Fournier, of Swanton, Vt., keeps about 25 6- to 12-month old heifers on the bedded pack.
The pack has meant better foot health and less laminitis in his heifers, Fournier said. “They also learn the social order at a young age and that takes a lot of stress off the animal.
The 50-by-80 foot barn has 1,500 square feet for animals, or about 100 square feet per animal. “That’s the bare minimum,” Fournier said. “That’s where most people get into trouble – it’s because they have way too many animals for the facility.”
He’d considered a composting pack, but his supply of sawdust is unreliable. “If you don’t have sawdust, you’re in a mess,” he said. Fournier beds twice weekly over a sawdust base, with straw chopped in a used REM straw processor. “Full-length straw gives more porosity, but chopped is easier,” he said. “You have to make it easy to do or it’s not going to get done.”
Thinking about a pack barn?
Consider these points:
• construction. A bedded pack barn costs roughly the same per square foot as a freestall, Gilbert said. A hoop barn with feed and scrape alleys will cost between $600 and $1,700/head, depending on whether you use your own labor and materials.
The Natural Resources Conservation Service or your state may help fund a pack barn because of its environmental benefits.
Aim for 70 to 100 square feet per animal. Design the pack to run the length of the barn, giving animals access from the long side. Build a low wall that keeps the pack level and limits access to several openings. “If cows can walk the whole open face, it becomes a ramp and they trample the pack; they don’t get a place to lie down,” Gilbert said. Feed and scrape alleys keep waterers off the pack and provide some raw manure for fields. Good ventilation is essential because the pack is a manure storage facility. Fans help dry out the pack and keep odors down.
• bedding materials. Compared to a freestall system, you’ll save money on manure handling, but spend more on bedding, since a bedded pack requires three to five times as much as a freestall. Endres estimates bedding costs at 60¢-80¢/cow daily.
Don’t skimp. “Even though bedding is expensive, don’t reduce the amount, because managing pack moisture is the most important thing you do,” Gilbert said. Use at least 10 lbs. of bedding per animal daily. Gilbert estimates a cost of $1.20/head, bedding at 15 lbs. per day ($15/yard for sawdust).
Sawdust, hay, straw, bark and wood chips – as long as they come from a well-maintained chipper so they don’t have splinters – can be used in a deep bedded pack. Sawdust, wood shavings or ground cornstalks are best for a composting pack, which needs carbon and nitrogen, plus bulk to allow air flow. Chopped hay and straw build up a mat that’s tough to till. The pack should be tilled twice a day down at least 10 to 12 inches, Gilbert said.
Turning the composting pack aerates and dries it out and can reduce the amount of bedding you need by 20 to 30%.
Other money-saving ideas:
• use the pack just half the year, with animals on pasture the remainder.
• grow your own bedding material.
• sell composted bedding to offset costs.
• build the pack with a separate feed alley. Animals excrete more when feeding, so less bedding will be required, but you may need a liquid manure system for handling feed-alley manure.
Endres has been studying corn cobs, woodchip fines and soybean straw as bedding. She said they will work as well, although excellent management is critical.
The labor involved in cleaning out the barn once or twice year depends on what you do with the manure. The producer in the Cornell study took 160 hours to remove manure and spread it in a compost pile. It took Fournier just four hours to clean his barn out with a skid-steer, excavator and dumptruck, and then pile it. “So from a labor standpoint, it’s a lot more efficient than a liquid system,” he said.
• compost as soil amendment.
Manure from a bedded pack can increase the microbial population and organic matter in the soil. But although the term used is “composting barn,” further composting is probably necessary to raise temperatures enough to kill pathogens sufficiently.
Temperatures in noncomposting packs run 80° to 100° F; in composting packs, they reach up to 110° F. But compost should reach at least 130° F for mature composting.
Compost loses about 20% of its nitrogen in the field the first year, vs. 90% from a liquid manure in which N is highly available. “So it takes some patience and planning to get payback. You may want to save some liquid manure to provide the flush of N in spring,” Gilbert said.
Survey: Dairy facilities
In preparation for the January 2010 editions of Western DairyBusiness (WDB) and Eastern DairyBusiness (EDB), editors surveyed dairy producers on their 2010 dairy facility plans. Among the highlights:
• WDB survey respondent herd sizes ranged from 150-3,000 cows. About 75% said they would change or make improvements to dairy facilities in 2010. Transition, maternity, hospital/treatment areas and heifer facilities will be targeted, with parlor, cattle resting, feeding and lanes/holding areas also getting some attention.
Cows come first. Although productivity and efficiency were cited, efforts to improve herd health and reduce cow stress were cited as the primary reason for facilities’ investment. Of course, improving health and reducing stress should add to productivity. WDB respondents are equally split between building new and retrofitting facilities.
• EDB survey respondent herd sizes ranged from 110-560 cows. About 83% said they would address dairy facilities in 2010. This region has seen a lot of investment in transition cow facilities in the past decade. If facilities’ investment is an indicator, more producers will be bringing heifer-raising enterprises back home: replacement heifer facilities will get the greatest attention in 2010. Calf, cow resting and feeding areas addressed to a lesser extent.
Facilities getting worn out. Improving herd health and reducing cow stress were cited as reasons for facilities’ investment in 2010, but the majority of EDB respondents said existing facilities are outdated or worn out. EDB respondents are more likely to retrofit.
Read about it
When it comes to what they want to read about, WDB respondents cited ventilation and calf/heifer facilities; EDB readers cited cow comfort and cattle resting topics, with keen interest in bedded pack areas.
Congratulations to Lynda Foster, dairy producer from Fort Scott, Kan., who was drawn as the winner of the $100 VISA gift card from all those completing the online survey.