Experimental Salmonella infection in calves. 1. The effect of stress factors on the carrier state.

Four calves were infected with 2.4 x 10(8)S. dublin and penned separately. Fluctuations in environmental temperature did not affect the symptoms of the disease or the duration of excretion. Faecal samples were superior to rectal swabs for detecting excretors.After transport stress, Salmonella was isolated from several organs at slaughter in an excreting calf, and uninoculated control calves became cross-infected. During slaughter, carcasses became contaminated on their surfaces. From one contaminated carcass Salmonella was recovered after chilled storage at 0 degrees C. for 1 week and also after freezing at -20 degrees C. for 1 month.