Evaluation of a micro method for the routine determination of serum pepsinogen in cattle

Estimation of serum pepsinogen concentration in cattle is used to aid the detection of clinical or subclinical infections with the abomasal nematode Ostertagia ostertagi. An inexpensive, simple micro method for the routine determination of pepsinogen concentration in bovine serum samples is described which is based on the hydrolysing effect of serum on buffered bovine albumin substrate. Comparison of this assay with a macro method, based on the same principle, gave almost identical results in the range of 0 to 10 Units tyrosine. The reproducibility of the assay was shown to be very satisfactory, intra-assay and day-to-day coefficients of variations were less than 4.7 and 8 per cent, respectively.