Use of procalcitonin, neopterin, haptoglobin, serum amyloid A and proinflammatory cytokines in diagnosis and prognosis of bovine respiratory disease in feedlot calves under field conditions.

Bovine respiratory diseases (BRD) have long been considered a serious problem that causes major economic losses in feedlot calves (FC). This study aimed to determine the diagnostic and prognostic effect of selected biological markers including, procalcitonin (PCT), neopterin (NP), proinflammatory cytokines (IL-1β, IL-8, TNF-α, IF-γ), haptoglobin (HP) and serum amyloid A (SAA) on FC with BRD under field conditions. Sixty-nine FC that were identified to be infected with Mannheimia haemolytica and Histophilus somni and had different clinical respiratory signs (diseased group) were selected for this study.