For suppliers of entire males, it is best to transfer the pigs directly from the pens to the transport truck. Alternatively, the suppliers should ensure that the pigs spend as little time as possible in small groups in the pick-up facilities. If this practice is followed, the level of skin damage will usually not be higher in deliveries of entire males than in deliveries of only sows and castrates.
Although the behaviour of the entire males is highly variable during lairaging at the slaughterhouse, the calm environment in the lairage pens tends to be disturbed by sexual and aggressive behaviour when entire males are present. Generally speaking, the presence of male pigs adversely affects the welfare of the lairaged pigs, which do not have the possibility to rest undisturbed or avoid adverse sexual and aggressive behaviour. It makes no difference whether there is a small or large number of entire males in the lairage pen in question.
If in future a large percentage of male pigs are delivered uncastrated, it might be necessary to implement both tighter control of the logistic in the transport of animals to the slaughterhouse and greater flexibility regarding the order in which the lairaged pigs are slaughtered, since some of the entire males delivered for slaughter can be extremely agitated and should be slaughtered as soon as possible after arrival.
Larsen, H.D., Nielsen, D.B., Blaabjerg, L.O. (2017). The influence of male pigs on animal welfare at the day of slaughter . WAFL, 7th International Conference on the Assessment of Animal Welfare at Farm and Group Level, Wageningen, The Netherlands, September