Kongsted Hanne, Foldager Leslie, Sørensen Jan Tind
1Department of Animal Science, Aarhus University, Blichers Allé 20, DK-8830 Tjele, Denmark.
2Bioinformatics Research Centre, Aarhus University, C.F. Møllers Allé 8, DK-8000 Aarhus C, Denmark.
Porcine Health Manag. 2020 Apr 14;6:10. doi: 10.1186/s40813-020-00149-z. eCollection 2020.
We investigated the prevalence of tail lesions in batches of undocked slaughter pigs in herds just before delivery to an abattoir. At the abattoir, dehaired and scalded carcasses were submitted to routine meat inspection which included recording of tail lesions. The purpose of the study was to investigate the relationship between clinically and abattoir- detected tail lesions in undocked pigs. During visits in 15 label-production herds, 2346 slaughter pigs from 24 batches were examined. Tail lesions were registered as mild healed, mild unhealed or severe. The median prevalence of the three categories in batches was 13, 9 and 6%, respectively. At the abattoir, tails were evaluated by public inspectors. Between 0 and 10% of pigs within batches (median: 1%) were registered with tail lesions at the abattoir. A linear regression model was used to compare the proportions of severe tail lesions registered in each batch within the herds with the proportions registered at the abattoir. We applied a leave-one-batch-out internal cross-validation on the model in order to explore a systematic relationship. The mean absolute difference between the predicted and the observed proportion was 9%-points. The coefficient of determination (r) was 0.006. Our results indicate that there is no systematic relationship between clinically and abattoir-registered tail lesions in undocked pigs. Thus, abattoir registrations as carried out in the present study did not mirror the clinical situation properly. If meat inspection recordings should be used to reflect tail lesions in the herds, efforts must be undertaken to ensure a positive correlation between the two. Thus, abattoir registrations used as an indicator of tail bite prevalence in herds are currently not reliable.
我们调查了即将送往屠宰场的猪群中未断尾的待宰猪尾巴损伤的发生率。在屠宰场，经过脱毛和烫毛处理的猪胴体要接受常规肉类检查，其中包括记录尾巴损伤情况。本研究的目的是调查未断尾猪临床发现的尾巴损伤与屠宰场检测到的尾巴损伤之间的关系。在对15个有标识生产的猪群进行走访期间，对来自24个批次的2346头待宰猪进行了检查。尾巴损伤被记录为轻度愈合、轻度未愈合或重度。这三类损伤在各批次中的发生率中位数分别为13%、9%和6%。在屠宰场，由公共检查员对猪尾巴进行评估。各批次中0%至10%的猪（中位数为1%）在屠宰场被记录有尾巴损伤。使用线性回归模型比较各猪群中每个批次记录的重度尾巴损伤比例与在屠宰场记录的比例。我们对该模型应用了留一法内部交叉验证，以探索系统关系。预测比例与观察比例之间的平均绝对差异为9个百分点。决定系数（r）为0.006。我们的结果表明，未断尾猪临床记录的尾巴损伤与屠宰场记录的尾巴损伤之间不存在系统关系。因此，本研究中的屠宰场记录未能恰当地反映临床情况。如果要用肉类检查记录来反映猪群中的尾巴损伤情况，必须努力确保两者之间存在正相关。因此，目前将屠宰场记录用作猪群中咬尾发生率指标并不可靠。
