Sources of contamination during slaughter and measures for control

This paper is concerned with processes and procedures involved in the conta mination of beef, lamb and pork carcasses during slaughter. The hides of be ef and the fleece of sheep are major sources of carcass contamination. The spread of pathogens from beef hides to the carcass, operatives and surfaces in the abattoir is demonstrated. Efforts to clean the hide of cattle and t he fleece of sheep are outlined, with reference to the success of these tre atments in reducing carcass contamination. The effect of bringing very dirt y or dungy animals to slaughter is considered in terms of the effect on car cass contamination after slaughter. The influence of tying the bung (or rec tum) in reducing carcass contamination is discussed, as is the use of plast ic bags as an additional control in preventing pathogen spread on pig carca sses. The relationship of this revised procedure in reducing the occurrence of yersiniosis in Norway is shown. The use of a commercially automated sys tem to tie beef bungs is discussed in relation to reducing carcass contamin ation. A comparison between the removal of faecal contamination on carcasse s by trimming or using a new steam-vacuumized system is presented. The effe ct of preevisceration washing of beef carcasses is described and the ration ale relating to bacterial removal using this treatment is discussed. The in fluence of evisceration as a source of carcass contamination is demonstrate d in relation to sheep slaughter. The processes of carcass decontamination using washing with water at different temperatures, steam pasteurization an d hot lactic acid are compared in relation to their ability to remove bacte ria from beef carcass surfaces. Finally, the effect of line speed and the i mpact of technology advances on beef and sheep carcass contamination is rev iewed.