At Toronto Pig Save's morning vigil on Jan. 22, 2013, it was -12 ºC but felt like -20ºC with wind chill but for the pigs travelling on the highway on transport trucks it feels much colder b/e of the greater wind chill factor.
According to Agriculture and Agri-Food Canada "Recommended code of practice for care and handling of farm animals: Pigs" (1993), for trucks travelling at 80 km/hr, -12 would give you an unbearable -40 ºC, making an already horrific journey that much worse.
The report also states:
• Pigs have little natural protection from the cold and suffer frostbite quickly. Wind chill can kill pigs." (p. 36)
• A head wind or cross wind makes the chill effect even greater