Evaluation of the MISCO Palm Abbe PA-203X digital refractometer for estimation of serum total protein and serum IgG in neonatal calves

Abstract

Failure to absorb sufficient colostral immunoglobulins (Ig), termed failure of passive transfer (FPT), may predispose neonatal calves to the development of disease and impaired future performance. The gold standard measurement for FPT is laboratory analysis of serum IgG using RID or ELISA. However, this is too expensive to be part of routine on-farm monitoring programs. As such, historically many producers have indirectly estimated FPT rates through the measurement of serum total protein (STP) using optical refractometers. However, a digital refractometer was recently introduced which offers the option of testing using multiple scales including Brix (%), STP (g/dL), serum IgG (g/L) and colostrum IgG (g/L) (MISCO Palm AbbePA-203X. MISCO. Cleveland, OH). The objective of this study was to describe the test characteristics of the MISCO Palm Abbe PA-203X digital refractometer for the measurement of STP and serum IgG. If successful, then either of these scales could be a useful tool for monitoring colostrum management on dairy farms.