A RAPID FIELD-TEST FOR THE DETERMINATION OF COLOSTRAL INGESTION BY CALVES, BASED ON GAMMA-GLUTAMYL-TRANSFERASE

A qualitative field test for determining the blood level of the enzyme gamma-glutamyltransferase is described for the evaluation of colostra l ingestion. The method for enzyme determination is based on dry chemi stry technology, and a simple 37-degrees-C incubator and colour chart for estimating the activity. There were good correlations between resu lts obtained with the field tests and those obtained with the Reflotro n(R) and the wet chemistry conventional methods. Following colostral i ntake by the calf, blood gamma-glutamyltransferase increased more than 1 00 fold. There were good correlations between gamma-glutamyltransfe rase and total globulins in the serum on days 2 and 3 after colostrum intake. Lower but significant correlations were seen between the enzym e and serum total proteins. Good correlation was also seen between the serum enzyme activity and the albumin to globulin ratio. Electrophore tic separation of calf serum showed a significant increase of gamma-gl obulins after colostral ingestion. The implications and importance of field test are discussed.