Sex-based differences in plasma chemistry and cardiac marker test results in Siamese fighting fowl

Background: Variations in the results of plasma chemistry analysis as a function of sex have rarely been demonstrated in avian species. Objective: The aim of the present study was to investigate sex-related differences in values for routine biochemical variables, including conventional muscle enzymes, and novel cardiac markers in female and male Siamese fighting fowl. Methods: Plasma chemistry analytes and cardiac marker proteins (creatine kinase-MB and cardiac troponin T) were measured in 70 Siamese fighting fowl using automated chemistry and immunoassay analyzers. Data were compared by 2-tailed t tests between sexes, and Spearman rank correlation between conventional and novel cardiac markers. Results: Male fowl had significantly higher uric acid concentration and γ-glutamyltransferase activity; whereas, female fowl had significantly higher total cholesterol, triglycerides, and calcium concentrations, and alkaline phosphatase activity. As compared with female fowl, the fighting cocks also had significantly higher plasma concentrations of creatine kinase-MB and cardiac troponin T. Significant correlations between cardiac troponin T, but not creatine kinase-MB, and the activities of conventional muscle enzymes (creatine kinase, aspartate aminotransferase and lactate dehydrogenase) were observed in male but not in female fowl. Conclusion: These results indicate that sex-specific differences exist for several biochemical parameters and cardiac marker proteins in fighting fowl, and that such differences should be considered in interpreting laboratory test results.