Comparison of agarose gel electrophoresis and capillary zone electrophoresis for serum protein analysis in small ruminants

Serum proteins play central roles in the inflammatory response and maintaining homeostasis. Serum protein electrophoresis is widely used in veterinary medicine, including in small ruminants, to detect inflammatory, infectious, and metabolic disorders by evaluating the protein electrophoretogram. Among the most frequently employed techniques in clinical laboratories are agarose gel electrophoresis (AGE), a laboratory method that separates serum proteins into 5-6 fractions using a solid matrix, and capillary zone electrophoresis (CZE), a more recent approach offering greater analytical precision and resolution. This study aimed to compare AGE and CZE for the analysis of the serum protein profile of small ruminants, establish reference intervals (RI), and assess agreement between fractions. Samples from 65 goats and 68 crossbred adult sheep, all clinically healthy, were analyzed. Fractions of albumin, α-, β-, and γ-globulins were identified and quantified. Data were evaluated using Spearman/Pearson correlations, Passing–Bablok regression, and Bland–Altman analysis. The results indicate that both methods are suitable for serum protein fractionation, showing a high degree of agreement overall. AGE demonstrated more robust quantification of γ-globulins, whereas CZE enabled further subdivision of β-globulins into β1 and β2 fractions and showed greater sensitivity in detecting immunoglobulin variations. While AGE profiles were characterized by the predominance of albumin and γ-globulins, reflecting physiological transport and immune functions, CZE provided superior analytical resolution. The established reference intervals proved consistent, confirming AGE and CZE as suitable and complementary methods. The standardization of species-specific values contributes to more accurate diagnoses and improved health monitoring of small ruminants.