Run your hand across the finish of the grooved concrete alleys in a newly-built free-stall barn, and often it feels rough with little bits of sharp concrete sticking up. Not at McCarty Dairy. "You could walk barefoot on our concrete," says Mike McCarty, partner in the 900-cow operation near Colby, Kan.

How did the dairy get such good concrete? The dairy's concrete was poured using the same technology used to build the nation's Interstate highways - a slip-form-concrete paving machine. Slip-form concrete saves time, because no forms are needed, and it delivers consistent depth and quality.

The McCartys were sold when they saw the finished product at another dairy and examined it for cow comfort. "The cows spend a lot of time on concrete, and this is one area we wanted done right," says McCarty. And, after nine months in their new dairy facility, the McCarty's haven't been disappointed. "We haven't sold a single cow for a lameness problem due to concrete," he says. Their overall cull rate is running a little less than 2 percent per month.

If you're expanding or building a new dairy, you may want to consider using slip-form concrete.

Not just for large dairies
One primary advantage of slip-form concrete is the ability to do long, straight runs quickly. But, that doesn't mean you have to have thousands of cows to consider using it.

Mike Dalrymple, of High Plains Dairy Construction in Syracuse, Kan., says a 400-cow facility is probably the smallest dairy where they would use the paving machine. Meanwhile, the smallest job done by Design Builders, of Fort Morgan, Colo., involved two 200-foot-long feeding areas for outside lots. The minimum size pour that a contractor will do, using slip-form, will vary with the size of the slip-form paving machine and the economics of the situation.

The paving machine uses molds to form the concrete. Therefore, a 20-foot-wide feed alley requires a different mold than a 14-foot wide cow alley with a rear curb. It takes up to a day to change molds. So, you really have to pencil out the time and cost of slip-form paving against hand-pouring the concrete to see which is most economical.

Cost is the other consideration. At High Plains Dairy Construction, the subcontractor who owns the paving machine charges 10 cents per square foot of concrete poured. However, Dalrymple says his company absorbs that cost due to the tremendous savings in labor when compared to hand-pouring a dairy facility. In fact, the two pretty much balance out. Most contractors charge the same rate, or sometimes even a bit less, for slip-form concrete when compared to hand-poured concrete.

Quality done fast
One of the virtues that producers and contractors extol about slip-form concrete is the savings in time. For example, by using slip-form paving, you could pour a 22-foot wide feed alley, 1,500 feet long in one day. It would take seven to eight days to pour the same area by hand.

Keeping on schedule is important when building a new dairy, stresses Buddy Nichols, of Morwai Dairy in Hudson, Colo. Using slip-form concrete, the builder can pour all of the alleys quickly, and then the rest of the crews can get in there and start working. That can shorten the total window needed to complete construction, or help make up time if construction has fallen behind schedule.

And, because a paving machine is used to lay the concrete, it delivers a uniform depth, consistent finish and consistent grooving.

"You can look down the barn and see straight-line grooves," says McCook, Neb., veterinarian Joe Gillespie, who works with McCarty's and other large dairies in the region. You don't see any wavy lines up and down or side to side when you look down the alleys. The grooves are one continuous line. When flushing the barns, there is less breakup of the water stream, so you get really clean alleys. In addition, when using a scrape system, slip-form concrete has fewer rough edges or bumps to catch the loader bucket, so you get a cleaner floor.

Since the paving machine controls the depth of the concrete, you get a consistent pour, too. This eliminates fluctuations in depth, which can lead to additional concrete being used.

Both High Plains Dairy Construction and Design Builders have created their own attachment for the paving machine so they can install grooves, too. In one pass, the paving machine sets the width and depth of the concrete, vibrates it to remove air bubbles, levels and trims the concrete, and then grooves it.

It's good for cow comfort
"I told the contractor I wanted the concrete to be smooth enough that it could be put around a pool for kids to run on barefoot, yet have grooves for the cows' feet to grip," says Andy Keeter, dairy manager at Dairy Oz, a 1,600-cow dairy in Deerfield, Kan.

None of the producers - Keeter, McCarty or Nichols - had to scrape or scabble their concrete to get it ready for cows.

Lameness rates and cull rates at these farms were less-than-anticipated. "We haven't seen the bruising on the cows' soles that you normally see in a new facility," says Keeter.

The 4,000-cow Morwai Dairy has averaged just 40 sole abscesses per month during the first year of operation. That's just 1 percent per month.

Of further note is the cows' ability to show heat. At Prairie Land Dairy in Firth, Neb., partner Dan Rice says the "cows show excellent heats in the new barn. Our vet can't believe how well our breeding program has been going even with this past summer's heat." Part of that success is how well the cows show heat in the new barn, combined with the use of pedometers and a sound reproductive management program.

Although the 750-cow dairy has had to block some cows with thin soles, overall foot health in the new free-stall barn which has slip-form concrete is a lot better than the animals in the old free-stall barn.

At McCarty Dairy, owners there believe the excellent concrete they have is one of the factors that has helped them achieve a 12.5-month calving interval. "Cows regularly show heat in the free-stall alleys," says McCarty.

It takes more than good concrete
Slip-form concrete is not a magic bullet, warns veterinarian Gillespie. Other factors besides new concrete can contribute to high cull rates and lameness problems in an expansion. It takes a good management package - nutrition, health, foot trimming, and a management team that pays attention to details - to get good results.

Before investing in slip-form concrete, be sure to inspect projects completed at other dairies so you have a good idea what to expect.