Serum iron concentration is candidate inflammatory marker for respiratory diseases in beef cows.

We hypothesized that the serum iron (Fe) concentration in cows with respiratory diseases is a satisfactory substitute for major inflammatory markers such as haptoglobin (HPT) and serum amyloid A (SAA). Twenty Japanese Black cows aged 279.6 ± 120.0 days were enrolled, and divided into respiratory diseases and control groups based on the presence of clinical findings of respiratory diseases. As a result, area under the receiver operating characteristic curves for plasma HPT, SAA and serum Fe concentrations for respiratory disease-associated systemic inflammation were excellent, at 1.00, 0.96 and 0.97, respectively. Therefore we confirmed that the serum Fe concentration is a satisfactory substitute for HPT and SAA in beef cows with respiratory diseases.