Clinical condition of cull sows before and after transport to slaughter – Effects of journey duration and a stationary period

Abstract

This factorial study was part of a project examining potential welfare challenges for cull sows in the pre-slaughter logistic chain, and examined effects of journey duration and presence of a longer pre-planned stop half-way during journeys on their post-transport clinical condition. The sows were transported 4, 6 or 8 h under conditions modelling typical Danish practice. In addition, across 49 journeys, effects of temperature inside the vehicle and time spent waiting before unloading at the slaughterhouse were examined. The results confirmed the findings of our earlier observational study, showing that the clinical conditions of cull sows deteriorated during transport, but also that none of the 578 sows arrived at the slaughterhouse in a condition that would have rendered them unfit for transport. A complex picture was found in relation to the clinical variables affected by journey duration, involvement of a longer pre-planned stop, and/or time spent waiting before unloading. This suggests that several factors contribute to the deterioration of the clinical condition of sows, but not consistently or as unequivocal causal factors, at least within the studied journey durations. Based on the deterioration in their clinical condition, especially for variables associated with heat stress and aggression, and knowing that the amount of time the sows are exposed to hazards such as aggressive pen mates, high temperatures and/or moving vehicles is dependent on the journey duration, keeping journeys as short as possible will most likely be advantageous. Future studies should also focus on how to optimise the social and microclimatic environment.