[Stress and immunity in cattle]

Stress of variable length may be caused in calf by parenteral administration of supercortisol and application of acute thermal load. Hormonal or thermal stress may have negative impact on postvaccinal immunity to paratyphoid (Salmonella dublin 81), as may be interpreted with reference to the O-agglutination titre of blood serum. The extent to which immunity is suppressed by stress was found to depend on the moment of stress application, duration of stress, and age of the calf.