Pigs have high sensory capacity when it comes to hearing and smell. To reduce stress, noise levels should be low; further research is needed on how smell affects pre-slaughter handling. Pigs do not see very well. During driving to stunning, distracting stimuli should be kept to a minimum; the speed of driving as well as general handling routines should be adapted to biological principles for pigs.
Even though race systems are optimized according to the latest knowledge, it has become apparent that it is unrealistic to expect pigs to enter a chute without prompting. Furthermore, it is impossible to standardize handling regimes on the day of slaughter. Consequently, minimal human handling is desirable.