ABSTRACT
The degree of stress to which cattle are subject in shipment is directly related to the amount of respiratory disease cattle experience after shipment. Respiratory diseases in cattle follow a sequence from stress to virus infection to bacterial infection in that an animal often has the virus in its body. Because stress is a major factor in cattle disease, one would think that stress could be easily defined and easily measured. Cattle also experience two other conditions that cannot be classified as being entirely physical stress because there is a great deal of psychological influence in the stress involved. Acute stress can usually be classified as fear or anger and elicits the fight or flight response wherein the adrenal medulla releases adrenalin resulting in increased strength for a short period of time. The body responds by increasing the production of the corticosteroids from the adrenal cortex.
