Unhealthy legs and claws in pig production are a persistent problem, a primary reason for which seems to be inappropriate floor properties in the pig pen. Inadequate frictional properties or low coefficient of friction (COF) may result in slippery floors and slip injuries to pigs. This thesis presents basis of design criteria for pig house floors with the aim of minimising the number of claw disorders. Parameter values were determined by pig gait studies in a gait analysis laboratory, where the pigs walked a straight or a curved test aisle. The gait was recorded by a force plate and a perpendicularly placed digital video camera as the pigs walked the test aisle. The specific aims of the four studies included in the thesis were to: 1) characterise pig gait and describe the effect of clean and fouled floor conditions for pigs walking a line on solid concrete, walking a curve on solid concrete and walking a curve on rubber mat; 2) determine the utilised COF (UCOF) of the walking pigs and compare it with measured dynamic COF (DCOF); and 3) analyse pig slip in different floor conditions. A set of parameter values characterising pig gait in clean and fouled concrete floor conditions were obtained by kinematic and kinetic methods. The data showed that pigs walking a straight line adapted their gait to fouled floor conditions. Pigs were able to adapt to walking a curve in clean floor conditions but the observed adaptation was not enough for safe walking in fouled floor conditions, where UCOF exceeded DCOF. Walking a curve on fouled rubber mat gave better traction and reduced forward and backward slips by over 50% compared with walking a curve on fouled concrete. The discrepancy between UCOF and measured DCOF observed in the studies could be due to the friction measuring device underestimating the actual risk of slipping and falling in fouled floor conditions, especially when walking a curve. Additional studies are needed to provide pig producers with more detailed information, e.g. guidelines for required COF values in pig pen situations where the required motion and speed of motion are determined. An appropriate data set for COF measurements at farm level can bring safer and more slip-resistant floor solutions in the future
