Assessment of Colostrum Quality in Cattle Using Viscosity Measurements

The provision of high-quality colostrum immediately after birth is essential to ensure adequate passive transfer of immunity in neonatal calves. This study evaluated colostrum viscosity as a potential indicator of colostrum quality, its relationship with immunoglobulin G (IgG) concentration, and the influence of cryopreservation on viscosity measurements. Viscosity was determined in 200 colostrum samples using a cone–plate viscometer and an outflow funnel. IgG concentrations were measured using an enzyme-linked immunosorbent assay (ELISA). Viscosity measured by the plate–cone viscometer averaged 19.33 ± 22.98 cP. No significant differences were observed between viscosity measurements obtained before freezing and after thawing. Flow times through the outflow funnel averaged 18.48 ± 4.27 s. The mean IgG concentration determined by ELISA was 63.89 ± 23.50 mg/mL. Significant positive correlations were identified between viscosity and IgG concentration, between flow time and IgG concentration, and between viscosity and flow time. ROC analysis of the funnel method yielded an AUC of 0.821 (95% CI: 0.752–0.890), indicating good diagnostic performance for identifying poor-quality colostrum (IgG < 50 mg/mL). These findings indicate that viscosity using either a cone–plate viscometer or an outflow funnel is a useful proxy for IgG concentration and may serve as a practical method for assessing colostrum quality. Furthermore, cryopreservation had no detectable effect on colostrum viscosity.