The relationship between total protein in serum, glutaraldehyde coagulation test and disease in feedlot calves.

Serum from in all 249 calves were used to correlate the level of total protein (serum-Tp), gamma-globulin and the reaction of glutaraldehyde coagulation test (GCT) to each other. Further, of the 249 calves 219 were bled within two days after arrival to a feedlot and serum-Tp and GCT were related to subsequent diseases. The results revealed a close relationship between the three tests. Of the 219 calves 15% had a negative GCT (hypogammaglobulinemia) and 26% had a serum-Tp below 55 g/l. There was a significantly (p less than 0.001) higher disease frequency, 81%, in the GCT negative calves than in the GCT positive, 35%. Serum-Tp was significantly (p less than 0.001) higher in healthy compared to diseased calves. The mean values were 60.6, 57.2, 55.2 and 53.1 g/l for healthy calves, calves with respiratory disease, enteritis and both respiratory disease and enteritis respectively. Further, calves with a serum-Tp below 55 g/l developed disease earlier after arrival to the feedlot than those above this limit. It was concluded that both serum-Tp and GCT can be used in field investigation to identify calves predisposed to disease.