The term “in-transit losses” refers to the market weight pigs that die on the way to the packing plant or while they are in temporary holdings at the packing plant. This problem represents a significant welfare concern for the swine industry. A study in Ontario found that pigs are affected by both temperature and humidity; therefore reductions in density of pigs on trucks must take both heat and humidity into account. Farm of origin accounts for more variation due to in-transit loss than does the transport company or packing plant. Producers must implement changes in genetics, handling, and/or feeding practices to reduce in-transit losses. Pigs travelling large distances did not experience higher in-transit losses than those travelling shorter distances.