Context: Ecchymosis is an undesirable appearance in meat caused by small bleeds from capillaries broken during the slaughter process. These lesions are heavily trimmed during processing, incurring labour costs and yield losses.

Aims: To estimate the prevalence of ecchymosis in a South Australian abattoir and investigate potential predisposing factors.

Methods: A generalised linear mixed model estimated the effects of breed, age, slaughter shift (morning or afternoon), kill date, direct or market consignment, hot standard carcase weight (HSCW, kg), deviation from lot average carcase weight (ZHSCW, standard units), palpated fat score (mm) and time in lairage (h) on the prevalence of ecchymosis. Over 7 days, 12 286 lamb and 3802 mutton carcases from 82 properties were scored (0, 1) for ecchymosis.

Key results: Lambs had a higher prevalence of ecchymosis (14%) than did mutton (1%; P < 0.001), with significant variation between lines of lambs (P < 0.001). Considering lambs only, kill date (P < 0.01), time in lairage (P < 0.001), and the quadratic terms of HSCW (P < 0.001) and ZHSCW (P < 0.01) affected the prevalence of ecchymosis.

Conclusions: Ecchymosis had a significant prevalence in lambs only. The time lambs spend in lairage and their bodyweight may be predisposing factors for ecchymosis before slaughter and warrant further investigation.

Implications: The interaction of size and weight extremeness appeared to predispose lambs to developing ecchymosis at slaughter. Farm of origin was another identified risk factor (management group). Whether it was size and extremeness influencing body composition or other mechanisms involved in vascular integrity, is not known. Further research is required to identify these mechanisms so as to establish breeding and management guidelines that will decrease the likelihood and cost of ecchymosis in lambs. Ecchymosis remains poorly understood, but fractured capillaries indicate a weakness in vascular tissue. Given the present study included over 12 000 observations in 7 days, ecchymosis in lambs could be used as a model to study vascular weakness in humans.

背景：瘀斑是肉的不良外观，这是由于在屠宰过程中毛细血管破裂产生的少量出血引起的。在加工过程中会严重修剪这些病灶，从而导致人工成本和产量损失。

目的：评估南澳大利亚屠宰场的瘀斑患病率，并调查潜在的诱发因素。

方法：广义线性混合模型估算出以下因素的影响：品种，年龄，屠宰班次（上午或下午），宰杀日期，直接或市场寄售，标准箱体热重（HSCW，kg），批平均箱体重的偏差（ZHSCW，标准单位），触诊的脂肪评分（mm）和瘀斑患病率的回避时间（h）。在7天的时间里，对来自82个猪场的12 286只羊羔和3802只羊肉尸体进行了评分（0，1）。

关键结果：羔羊的瘀斑患病率（14％）比羊肉（1％；P <0.001）高，羔羊品系间的差异很大（P <0.001）。仅考虑羔羊，杀死日期（P <0.01），待宰时间（P <0.001）和HSCW（P <0.001）和ZHSCW（P <0.01）的二次项影响了瘀斑的患病率。

结论：瘀斑只在羔羊中有很高的患病率。羔羊花在驯养上的时间及其体重可能是宰杀前瘀斑的诱因，应进一步调查。

启示：大小和体重极限的相互作用似乎使羔羊容易在宰杀时发生瘀斑。起源农场是另一个确定的风险因素（管理组）。究竟是影响身体组成的大小和极限还是涉及血管完整性的其他机制尚不清楚。需要进一步研究以鉴定这些机制，以建立育种和管理指南，以减少羔羊瘀斑的可能性和成本。瘀斑仍知之甚少，但毛细血管破裂表明血管组织无力。鉴于本研究包括在7天内的12,000多次观察，羊羔的瘀斑可以用作研究人类血管无力的模型。