The significance of stressors in bovine respiratory disease in calves

The Bovine Rrespiratory Disease Complex (BRDC) in calves causes substantial economical losses due to treatment costs, loss of animals., growth retardation and diminished carcass quality. BRDC is a multifactorial disease, which is elicited by interactions between the host and a number of risk factors, among these viruses and bacteria as well as environmental;factors (climatic conditions, hygiene, management at calving, nutrition, dehorning commingling, and transportation). The usage of antibiotics in the metaphylaxis and treatment of BRDC is a widespread routine. The need to reduce the number of antimicrobial treatments in food producing animals demands to intensify the advisory work in order to gain a reduction in the number of risk factors ("stressors") that contribute to the occurrence of BRDC in calves. To this end, a number of guidelines, checklists and monitoring protocols for evaluation of the health status and the environmental conditions as well as animal behaviour are available, but are not used on a routine basis in bovine practice. Advisory work should aim at reducing the intensity of exposition as well as the number of risk factors that contribute to the occurrence of BRDC. Daily observations are needed to identify, examine and treat affected animals in the initial phase of BRDC in order to avoid irreversible alterations of the lung.