Evaluation of two commercial agarose gel kits for estimating IgG concentrations in neonatal calves: A pilot study.

This study characterized agarose gel electrophoresis (AGE) profiles of calf serum and evaluated the accuracy of two commercial AGE kits (J711 and J718) for estimating immunoglobulin G (IgG) concentrations. Samples were collected from 10 calves at birth (Day 0), 10-12 h later (Day 0.5), and 2 days after colostrum ingestion (Day 2). AGE was performed with both kits, and IgG concentrations were measured via ELISA. After colostrum ingestion, β2 globulin (Glb) and γGlb fractions merged electrophoretically and were analyzed together as β2γGlb. On Day 0, γglobulin was nearly absent, confirming no transplacental Ig transfer. By Day 2, β2γGlb had markedly increased. Linear mixed-effects models showed that β2γGlb was a strong predictor of IgG levels, with marginal R2 values of 0.960 (J711) and 0.958 (J718). The results suggest that the AGE kits have potential as a practical alternative for evaluating passive immunity in calves.