[The serum pepsinogen analysis and its relation to bovine ostertagiasis (author's transl)].

An outline of literature on the pepsinogen analysis and its application, especially within the veterinary parasitology, is given. The pepsinogen content of the blood in experimental infection with Ostertagia larvae is mentioned. The authors state their own experiences with the analysis. Testing of 100 parasite-free calves kept indoors gave a mean value of 0.5 units tyrosin/litre. 95 of the calves were within the range 0.3-0.7 units. Flutuations of serum pepsinogen in the course of a subclinical infection in 6 calves during their first grazing season are described and compared to pasture contamination and egg excretion of the calves. In a second experiment the authors give a critical evaluation of the correlation between pasture contamination, weight gain, pepsinogen, and eggs in faeces. The correlation between pepsinogen and weight gain was found to be considerably higher than the correlation between e.p.g. and weight gain. A highly significant correlation between pasture contamination and serum pepsinogen (r=0.60-0.75) was found. The correlation between pasture contamination and e.p.g. was considerably lower (r=0.10-0.43) and only significant in a single case. The value of pepsinogen determinations in epidemiological experiments and weight gain experiments with calves is emphasized and the authors indicate possibilities of their application in practice.