INVESTIGATING THE IMPACT OF STRESS ON FOODBORNE PATHOGEN COLONIZATION IN TURKEYS
Location: Poultry Production and Products Safety Research
Title: Evaluation of ovotransferrin as a nonspecific marker of health problems in chickens
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 5, 2009
Publication Date: October 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. Evaluation of ovotransferrin as a nonspecific marker of health problems in chickens. Poultry Science. 88(10):2069-2074.
Interpretive Summary: Blood chemistries are normally used to differentiate between normal and healthy individuals since several components are elevated or decreased in the event of diseases. Based on our earlier identification of a blood protein in chicken called ovotransferrin (OVT) which increases in the event of infection, we sought to determine if it is also elevated under other metabolic health conditions such as leg problems and water belly syndrome that cause stress. Using an immunological assay method to measure ovotransferrin, we found that the elevation of OVT was only seen under infection but not in metabolic diseases.
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 physiological injury in chickens.