Submitted to: Poultry Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/5/2009
Publication Date: 10/1/2009
Citation: Rath, N.C., Anthony, N.B., Kannan, L., Huff, W.E., Huff, G.R., Chapman, H.D., Erf, G.F., Wakenell, P. 2009. Serum Ovotransferrin as a Biomarker of Inflammatory Diseases in Chickens. Poultry Science. 88(10):2069-2074. Interpretive Summary: Chickens experience a variety of stress which includes both infectious and non infectious disease problems. Whereas the viral, bacterial, and coccidiosis are infectious problems, the noninfectious problems include ascites, lameness, and immunity related diseases. Prior work from this laboratory showed a blood protein called “ovotransferrin” can be a useful marker to diagnose chronic bacterial and viral infections; hence, the objective of this study was to develop a measurement procedure for this protein and find whether it is specific for inflammatory and infectious diseases or is applicable to all stressful situations. Using blood obtained from different naturally occurring and experimentally induced problems, our results show that ovotransferrin is only elevated in chickens which have inflammation or infection.
Technical Abstract: Infectious and metabolic disorders are common in poultry which cause stress, poor performance, and mortality that results in considerable economic loss. Identifying the nature of stress in chickens will assist the development of appropriate measures to improve health and welfare. Acute phase proteins (APP) are hepatic proteins, the blood concentrations of which change significantly in the event of many health problems including inflammation and physical injuries. Thus, APP are used as non specific diagnostic markers for various health disorders. Our previous studies showed that serum ovotransferrin (OVT) is an acute phase protein in chickens. Therefore, in the present study we investigated whether OVT concentration can be a marker of physiological stress using sera from chickens with different infectious and metabolic disorders. A competitive enzyme immunoassay (EIA) was developed to measure serum OVT concentrations. The results show that with experimentally induced pulmonary hypertension syndrome (PHS) and tibial dyschondroplasia (TD) there were no significant changes in OVT levels compared with matched controls. By contrast, when chickens were infected with microbes such as the bacterium Escherichia coli, or protozoan parasites such as Eimeria maxima and E. tenella, there was a significant increase in the levels of OVT in the serum. Chickens with spontaneous autoimmune vitiligo also showed a significant increase in blood OVT levels. These studies suggest that blood OVT concentration is modulated under inflammatory and microbial stress and can therefore be used as a diagnostic marker of infection and inflammation in chickens.