Comparison of IgG and semiquantitative tests for evaluation of passive transfer immunity in calves

Abstract

Serum immunoglobulin (IgG) and semiquantitative tests are used for the evaluation of passive transfer immunity (PTI) incalves. We aimed to evaluate PTI in calves by using a Brix refractometer, total protein (TP), gamma-glutamyl transferase (GGT), andglutaraldehyde coagulation test (GCT) on days 1, 3, and 7 after birth; to compare the results with serum IgG; and to evaluate which daythese tests are given on will give the best results. The blood samples were collected from 60 Holstein dairy calves on day 0, just after birth,and on the 1st, 3rd, and 7th days after birth. The serum IgG concentration was measured by ELISA, the Brix % and TP concentrationswith refractometers, and GGT activity using a dry chemistry system. The duration of the GCT was determined in the first 60 min. TheIgG, TP concentration, and Brix % all peaked on the 3rd day of the study. GGT showed a significant decline after 24 h. Evaluating theBrix %, IgG, TP, and GCT levels more than 24 h after birth gives better results. However, GGT activity was observed as an early indicatorof failure of passive transfer, as the GGT levels were highest 24 h after birth.