Meat safety consequences of implementing visual postmortem meat inspection procedures in Danish slaughter pigs

The consequences of a change from a traditional meat inspection procedure, including manual handling, palpation and incision, to an entirely postmortem meat inspection procedure in Danish slaughter pigs were assessed by a comparative study of the two methods in 188,383 slaughter pigs. Out of 58 lesion codes (selected with a prevalence less-than-or-equal-to 5.5 x 10(-5)), 26 (45 percent) were assessed either as merely aesthetic or as the healed stage of an earlier lesion and nine (15 percent) as active, but local processes, occurring only in non-edible tissue.

Five lesion codes (9 percent) were assessed as active, non-abscessal processes occurring in edible tissue, caused by swine-specific pathogens and 10 (17 percent) were abscessal or pyaemic lesions occurring in edible tissue. Seven lesion codes (12 percent) may be associated with consumer health hazards (two frequently and five rarely), and one with occupational health hazards.

It was estimated that per 1000 carcases, an additional 2.5 with abscessal or pyaemic lesions (in edible tissue) containing Staphylococcus aureus, 4 x 10(-4) containing ochratoxin, 0.2 with arthritis due to Erysipelothrix rhusiopathiae, 0.1 with caseous lymphadenitis, 7.0 faecally contaminated with Salmonella species, and 3.4 faecally contaminated with Yersinia enterocolitica would remain undetected as a result of changing from traditional to the visual inspection procedure.

Two valuable reasons for implementing a visual control system are the potential for decreased cross-contamination (no handling, cutting and incision) and reduced inspection costs. The resources released as a result may be reallocated to hygiene and surveillance programmes.