The use of the milk ring test in a survey of the incidence of bovine brucellosis in southern Scotland.

Abstract

A report is made of a total of 438 simultaneous blood serum and milk ring tests, and an attempt made to evaluate the milk ring test as a diagnostic aid in individual animals.The ring test has been used to test the bulk milk from some 370 herds providing the greater part of the raw milk supply for Edinburgh.The incidence of viable Br. abortus in raw milk samples taken in the Edinburgh area has been studied together with the ring test reaction of such samples.The survey has shown that:(1) The ring test is correct in some 93 % of cases in detecting cows whose blood serum will be found positive to the brucella agglutination test.(2) The ring test, if carefully carried out, is a simple time-saving and accurate screening test for detecting herds possibly infected with brucella.(3) A high proportion of herd milks (53 %) giving a positive reaction to the ring test is disclosed, and the probable effect of vaccination with strain 19 in giving rise to this figure is noted.(4) The relatively high incidence (at least 10·5%) of Br. abortus in Edinburgh milk supplies is noted.Thanks are tendered to Dr Bruhn of the Veterinary School, and Dr Bendtsen, Veterinary State Serum Institute, both of Copenhagen and to Dr Stableforth of the Ministry of Agriculture and Fisheries Laboratory at Weybridge, for providing samples of stained antigen. Thanks are also due to the Bacteriology Department, Edinburgh University, for providing material from guinea-pigs and for relevant information; to J. Norval, Esq., M.R.C.V.S., for permission to obtain samples from the slaughterhouse, and also to the dairies and farmers who granted facilities for taking samples and to Miss Elma Chapman for assistance in the laboratory studies and in taking samples.