Contamination of pigs by nose-to-nose contact or airborne transmission of Salmonella Typhimurium Karine Proux, Roland Cariolet, Philippe Fravalo, Catherine Houdayer, André Keranflech and François Madec Vet. Res., 32 6 (2001) 591-600 DOI: 10.1051/vetres:2001148