A simple estimation of the immunoglobulin content of ewe colostrum.

Use of the optical refractometer in performing a rapid assessment of the immunoglobulin content of ovine colostrum under farm conditions was investigated. Refractometer readings were compared with total protein levels and with gamma-globulin levels, determined by the ZSTT, to assess the validity of the technique. In both cases correlation coefficients were high (0.98 and 0.79 respectively). Refractometry was shown to be a valid substitute for the ZSTT in studies on colostrum gamma-globulin levels.