EVALUATION OF A COMPETITIVE IMMUNOASSAY FOR THE DETECTION OF BOVINE HAPTOGLOBIN

A competitive immunoassay to quantify the serum concentration of bovin e haptoglobin (hp) using time resolved fluorescence was compared with an indirect method of hp assay (haemoglobin binding assay), using sera taken from healthy animals (n=158), animals experimentally infected w ith Haemophilus somnus (n=10) and from sick animals requiring veterina ry treatment (n=440). Upper limits of normality (for normal animals) w ere tentatively established for the immunoassay (2.1 mu g ml(-1)) and for the haemoglobin binding assay (103 mu g ml(-1)). The competitive i mmunoassay detected elevated hp in 62.5 per cent of field sera by comp arison with only 19.2 per cent using the conventional haemoglobin bind ing assay. Serum albumin concentration did not correlate with hp altho ugh concentrations of globulins and copper did correlate. However, the se parameters (serum globulin and copper) were found to be insensitive markers of inflammatory disease.