Frictional forces required for unrestrained locomotion in dairy cattle.

Most free-stall housing systems in the Netherlands are equipped with slatted or solid concrete floors with manure scrapers. A slipping incident occurs when the required coefficient of friction (RCOF) exceeds the coefficient of friction (COF) at the claw-floor interface. An experiment was conducted to measure ground reaction forces (GRF) of dairy cows (n = 9) performing various locomotory behaviors on a nonslippery rubber-covered concrete floor. The RCOF was determined as the ratio of the horizontal and vertical components of the GRF. It was shown that during straight walking and walking-a-curve, the RCOF reached values up to the COF, whereas for sudden stop-and-start responses, the RCOF reached values beyond the maximum COF that concrete floors can provide. Our results indicate that concrete floors do not provide enough friction to allow natural locomotory behavior and suggest that tractional properties of floors should be main design criteria in the development of better flooring surfaces for cattle.