VAN Donkersgoed Joyce, Jericho Klaus W F, Grogan Heidi, Thorlakson Ben
Alberta Agriculture, Food & Rural Development, 11 Bruns Road, Lacombe, Alberta, Canada T4L1P1.
Agriculture and Agri-Food Canada, Food Production and Inspection Branch, Animal Diseases Research Institute, Box 640, Lethbridge, Alberta, T1J 374.
J Food Prot. 1997 Dec;60(12):1502-1508. doi: 10.4315/0362-028X-60.12.1502.
An assessment was made of the association between tag (mud, bedding, and manure) attached to hides of beef cattle at slaughter and bacterial deposition on carcasses. A total of 624 carcasses from 52 lots of cattle in southern Alberta from January to June 1996 were studied at a high-line-speed abattoir (HLSP) which processed 285 carcasses per h and at a slow-line-speed abattoir (SLSP) which processed 135 carcasses per h. Tag was quantitatively assessed on the belly, legs, and sides of 12 carcasses per lot by the same project worker (lot tag score) and for each incoming lot of cattle by plant personnel (plant lot tag score). Swabs (approximately 10 by 10 cm) were taken from the medial rump and sacrum immediately after hide removal and from the brisket and top of shoulder after carcass splitting. These samples were pooled for each carcass and aerobic mesophilic bacteria, coliforms, and Escherichia coli were enumerated. The lot bacterial count was calculated by averaging the individual bacterial results of the 12 carcasses in a lot. At the HLSP, the lot side scores and the plant lot tag scores were negatively associated ( < 0.05) with the aerobic bacteria, coliforms, and E. coli . Counts were lower when tag was shaven off of the hides or when the line speed was slowed, but the reductions in counts were less than 0.5 log/cm. At the SLSP, the lot belly score was negatively associated ( < 0.003) with the aerobic bacterial counts. Neither the lot tag score nor the plant lot tag score were associated ( > 0.05) with the bacterial counts. Surface wetness of the hides was weakly ( < 0.05) associated with coli forms and E. coli counts. This study indicates that there is no consistent association between lot tag scores, plant lot tag scores, and bacterial contamination of carcasses. Changes in bacterial counts when associated with lot tag scores, plant lot tag scores, surface wetness of hides, line speed, or shaving off of tag were generally less than 0.5 log/cm. Thus, these variables are individually assessed as control points, but not critical control points of HACCP plans for the prevailing beef slaughter processes (including line speed adjustment at the HLSP) at the two plants studied.
对肉牛屠宰时附着在牛皮上的标签（泥浆、垫料和粪便）与胴体上细菌沉积之间的关联进行了评估。1996年1月至6月期间，在艾伯塔省南部的一家高速屠宰场（HLSP，每小时处理285具胴体）和一家低速屠宰场（SLSP，每小时处理135具胴体）对来自52批牛的624具胴体进行了研究。由同一名项目工作人员对每批12具胴体的腹部、腿部和侧面的标签进行定量评估（批次标签分数），并由工厂工作人员对每批进厂的牛进行评估（工厂批次标签分数）。在剥皮后立即从内侧臀部和荐骨处以及胴体劈开后从胸部和肩部上方采集拭子（约10×10厘米）。将这些样本合并到每个胴体中，并对需氧嗜温菌、大肠菌群和大肠杆菌进行计数。批次细菌计数通过计算一批中12具胴体的个体细菌结果的平均值来得出。在HLSP，批次侧面分数和工厂批次标签分数与需氧菌、大肠菌群和大肠杆菌呈负相关（<0.05）。当标签从牛皮上剃掉或生产线速度减慢时，计数较低，但计数减少量小于0.5 log/cm。在SLSP，批次腹部分数与需氧菌计数呈负相关（<0.003）。批次标签分数和工厂批次标签分数均与细菌计数无关联（>0.05）。牛皮表面湿度与大肠菌群和大肠杆菌计数呈弱相关（<0.05）。本研究表明，批次标签分数、工厂批次标签分数与胴体细菌污染之间不存在一致的关联。与批次标签分数、工厂批次标签分数、牛皮表面湿度、生产线速度或标签剃除相关的细菌计数变化通常小于0.5 log/cm。因此，这些变量应作为控制点单独评估，但不是所研究的两家工厂现行牛肉屠宰工艺（包括HLSP的生产线速度调整）的HACCP计划的关键控制点。
