Reference Intervals for Serum Protein Electrophoresis in the European Bison (Bison bonasus): A Comparison of Agarose Gel Electrophoresis and Capillary Zone Electrophoresis

Knowledge of the reference intervals for serum proteins of the European bison (Bison bonasus) can be of great help in the diagnosis of infectious and inflammatory diseases, which are very common in these animals; however, reference intervals for this species are unknown. A total of 131 serum samples were obtained from the European bison from different locations in Poland. Agarose gel electrophoresis (AGE) and capillary zone electrophoresis (CZE) were used to separate and identify protein fractions. In all sera, six fractions were identified: albumin, α1, α2, β1-, β2-, and γ-globulins by both analytical methods. Reference intervals (90% CI) were determined.. Comparisons were made to find significant differences based on the sex, age or lifestyle of the animals. Concordance between the methods was assessed using Passing–Bablok regression, Bland–Altman analysis, and Lin’s concordance correlation. A higher percentage of α1-globulins was found in the females than in the males. Captive bison had significantly lower γ-globulin levels compared to free-living bison. The γ-globulin levels increased with the age of the animals. The Bland–Altman analysis demonstrated a systematic bias indicating no good agreement between methods, and only the values for albumin, β1-, β2-, γ-globulins, and total globulins were considered acceptable according to Lin’s concordance correlation. Both methods are adequate for identifying serum proteins, but they are not interchangeable, necessitating the use of separate reference intervals for each method.