Bacterial count from bovine carcasses as an indicator of hygiene at slaughtering places: a proposal for sampling

Lasta, J. A.; Rodriguez, R.; Zanelli, M.; Margaria, C. A.

A sampling technique by which the whole carcass is rubbed with a polyurethane sponge was used to study bacterial status on 523 beef carcasses at six different slaughterhouses over four different years. Although some abattoirs were differentiated based upon the psychrotroph counts from their carcasses, effects on counts of visits and season of sample taking, as well as interaction year X abattoir found at the other plants were large enough to mask the abattoir effect. Mesophile counts were not consistent enough to discriminate abattoirs, while Enterobacteria, total and fecal coliforms, and Staphylococcus aureus coagulase-positive organisms showed very low counts and did not set apart differences. A guideline to monitor beef carcass hygiene and, indirectly, the hygiene of the slaughtering practices through the psychrotroph counts is proposed. A two-kinds sampling plan is suggested with "right-incorrect" as levels of hygiene. A sample unit (n) of 10, an acceptance number of contaminated carcasses (c) of 3, and a count limit (m) of 10(3) CFU/cm2 are proposed. Under this guideline, a lot of carcasses will be deemed as hygiene lacking when 4 or more, out of 10 carcasses, yield counts of 10(3) CFU/cm2 or higher.