Controlling contamination of ovine carcases

Summary

​Based on previous surveys it appears that on an industry basis, the microbiology of ovine carcases has improved dramatically in recent years. However, there is great variation in microbiology counts between plants.
In the latest baseline survey, when twenty companies were examined on an individual basis, the average carcase ranged from TVC of 25/cm2 at the 'best' plant to 6,000/cm2 at the 'worst'. There was a similar picture for E. coli contamination. At the best four plants 11% of carcases were contaminated while at the worst four plants 90% were contaminated.
MLA completed an investigation to try and identify which factors influence the hygiene status of the carcase.
Scientists used data from three plants from an in-depth study in 1996-98 and also visited these plants in early 2006 to observe how processes had changed over the 10-year period. Because these plants had also participated in the baseline studies of 1998 and 2004 the researchers were able to link process scores and micro counts over a long period.
In 1996 the three plants had similar process scores and micro counts but at one plant there were improvements both in process score and in micro counts on carcases. By 2006, there was a distinct difference between the microbiological quality of carcases at the improved plant and at the other two plants.
Looking at each plant’s slaughter and dressing line, the researchers constructed a list of 'good' and 'not so good' unit operations.
They gave a score to each operation and when these scores were added up at each plant, there was a difference between the three plants even though they all had inverted dressing systems.
This project identified that these differences were due to:preventing roll-back on the forequarterspreventing contamination from knivespreventing contamination from hands and armsremoving contamination by steam vacuumingminimising contamination from the gutpreventing urine contaminationprocessing at 'slow' speedmanagement of processing