The microbiological conditions of the carcasses of six species after dressing at a small abattoir

Abstract

At a small abattoir, samples were collected from carcasses of cattle, pigs, deer, bison, ostriches and emus at the ends of the dressing processes. A single sample was collected from each of 50 or 25 carcasses of each species, by swabbing a randomly selected area of 100 cm2. Total aerobes, coliforms and Escherichia coli were enumerated in each sample. The microbiological conditions of the carcasses were assessed by reference to the log mean numbers of total aerobes, coliforms and E. coli estimated from sets of counts recovered from 25 samples, or to the log total numbers of coliforms and E. coli recovered from each set of 25 samples. The log mean numbers of total aerobes on beef carcasses were about 2·5 log cfu cm−2. The log mean numbers of aerobes on deer carcasses were similar, but the log mean numbers on other types of carcass were 0·5–1 log unit more. The coliforms recovered from carcasses were largely E. coli, except for pig carcasses where E. coli were only about 10% of the coliforms recovered. Escherichia coli were recovered from the majority of samples from beef and pig carcasses, at log mean numbers about 1·5 and 2·5 log cfu 100 cm−2, respectively, and log total numbers recovered >3 log cfu 2500 cm−2. Escherichia coli were recovered from minorities of samples from deer, buffalo, ostrich and emu carcasses at log total numbers about 2 log cfu 2500 cm−2. The findings indicate that when carcasses of different species are dressed at an abattoir, similar microbiological contamination of the various types of carcass cannot be assumed.