Don’t skimp on sand in free-stalls or it could hurt lying time, according to research in the July Journal of Dairy Science.

Researchers at the University of British Columbia measured changes in sand-bedding depth and the impact that this had on lying time.

In one experiment, they found that lying time decreased by 1.15 hours in stalls with sand that was 2.4 inches below the curb compared to stalls filled to curb height. In fact, for every 0.394-inch (1 centimeter) decrease in sand bedding below curb height, cows spent 11 fewer minutes lying down per day.

In another experiment, cows using stalls with the least amount of sand — 5.4 inches below the curb (as shown in the photo at right) — spent 2.33 fewer hours lying down per day than when they were given access to stalls filled to curb height.

The researchers recommend that sand should be level with the curb. Therefore, groom stalls daily and refill them as needed to keep sand at curb height.