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Make the Most Out of Compost

07:34AM Oct 08, 2014

Alternative bedding offers Kentucky dairies an increase in production


What some people see as a decaying mix of plants and other organic matter, others see as fertilizer their gardens. In Kentucky, compost has become more than just fertilizer—it’s helping change the way dairy cows are cared for. 

At the beginning of 2014, Kentucky had about 80 deep compost-bedded pack barns on the state’s 734 dairies. The growth of the idea has been rapid—just a few years ago there were none. Dairy producer Bill Crist was one of the early adopters. He leapt into compost pack bedding in 2010 by building two new barns on his farm near Glasgow, Ky. 

Prior to the move, Crist was milking two herds, one in a freestall barn and the second on a pasture-based system at separate farms. Since the move, Crist says he’s seen many positive changes in his herd. 

“Cull rates have gone down and we don’t have injured cows, so I love it,” Crist says of the bedding system. “There are a lot of different reasons why our cull rate is low, and it all comes back to the comfort level of the cows.”

Compost bedding melds the best parts of Crist’s former housing systems.  The compost-bedded pack barn is a loose housing system without stalls, just a large open resting area for cows. Crist has the ability to better monitor and feed cows as in the freestall, and he sees the feet and leg benefits comparable to pasture grazing.

Reduced lameness has been one of the biggest benefits. “I hate to say lameness is non-existent, but the hoof trimmer was here in March, and out of 500 cows he didn’t have to put a block on one. It was the same this past fall,” Crist says. Heel warts are minimal as well.

Lower culling rates were Bill Crists’ first clue to the benefits of a compost-bedded pack barns.

Milk quality has been another area of improvement since moving into the compost-bedded pack in September 2010. In the prior housing types, somatic cell counts (SCC) averaged 275,000 cells/mL in the winter. During the summer, the pasture herd would jump up to an SCC of 500,000 cells/mL, while the freestall cows were about 300,000 cells/mL. 

Within six months of moving the cows to the new facilities, Crist saw the average herd SCC drop below 200,000 cells/mL. It hasn’t risen since.

After each milking, the pack is tilled with a rototiller pulled by a compact tractor. Sawdust, called flour, is added to the pack approximately once a week and is sourced from wood used in cabinet manufacturing.

“It still takes management, and you’ve still got to work with it,” Crist shares. “It’s just as much work as a freestall. If you don’t till it, you’re going to be in trouble.”

This past winter was particularly cold in Kentucky. To help keep the pack from freezing, Crist had to till more frequently and add sawdust at least twice a week.

Another winter time issue is finding sawdust. Many of the saw mills used their own sawdust as a source of heat. During the holidays, it can be difficult to find sawdust because the factories are closed. 

Flexibility to make alterations to the barn in the future is another reason to consider using the compost-bedded pack, Crist says. If necessary, he can change his compost-bedded pack barn into a freestall barn, but he doesn’t see that happening anytime soon.

More research on compost-bedded pack barns is on the way. Researchers at the University of Kentucky are looking at deep compost-bedded pack barns as part of the school’s construction of a new dairy. “I’m excited about the opportunity to have this in a research environment,” says Jeffery Bewley, University of Kentucky assistant professor in dairy systems management.

Before coming to the university, Bewley did not have the best perception of compost-bedded pack barns because he associated them with the straw-bedded pack barn his grandfather used. New age compost barns, however, are very different.

“In fact, we are intensively managing the compost process. When we manage that compost process correctly, it helps keep the cows dry and clean. It is a very different system than what I had in my mind,” Bewley says.

Compost pack bedding is gaining popularity with Kentucky dairy producers because of the state’s mild winters, ease of access to reasonably priced sawdust, smaller herd sizes and the lower cost compared to other housing.

“We generally think about these barns costing 60% of the investment cost of a freestall barn,” Bewley says. “That can be beneficial for new farmers or people who have only typically had cows on pasture.”

Bewley does caution that the compost-bedded pack is a biological system and must be treated as such. He recommends a pack temperature range of 110° to 150°F and moisture to be 45% to 55%. 

Producers need to stir packs frequently with either a cultivator or rototiller. If using a rototiller, there needs to be 12" to 18" of penetration to get the compost working.

“When these systems are managed well, we can have clean and dry cows,” Bewley says. “I’m a big advocate of cow comfort, and we can make all of these systems work.”

To watch a Southeast United Dairy Industry Association video featuring Bill Crist, visit 

Here are additional resources from the University of Kentucky on Compost Bedded Barns: