1Department of Animal Science,Aarhus University,Blichers Allé 20,8830 Tjele,Denmark.
2SEGES,Danish Pig Research Centre,Axeltorv 3,1609 Copenhagen V,Denmark.
Animal. 2018 Dec;12(12):2609-2618. doi: 10.1017/S1751731118000563. Epub 2018 Mar 25.
Tail biting in domestic pigs relates to a range of risk factors, primarily in the pigs' environment. Preventive tail docking is widely used, and various experimental approaches suggest that docking reduces the risk of tail biting. However, whether the docking length affects the prevalence of tail biting outbreaks is less studied, as is how a shortened tail will affect pigs' social behaviour. The aim of this study was to investigate how three different tail docking lengths, measured at docking, as well as retained intact tails (Short: 2.9 cm; Medium: 5.7 cm; Long: 7.5 cm; and Undocked) affected tail biting risk and behaviour directed at other finisher pigs with the same docking length treatment. Tail lesions were scored weekly, as was behaviour at pen level after introduction to finisher pens and until a potential outbreak of tail biting or slaughter. Pigs from four commercial herds (258 litters) entered the study. Before the pigs entered the finisher section and data collection started, some pigs were excluded, mainly due to tail biting outbreaks in the weaner section. The risk of a tail biting outbreak differed significantly between treatments (P=0.001), with a lowered risk of a tail biting outbreak in Short pens compared with Undocked (P<0.001) and Medium (P<0.05), and was affected by herd as well (P<0.001). Pens in the Long and Undocked treatments were pooled for the behavioural analysis due to low representation, especially in the Undocked treatment. The probability of tail contacts, where a pig interacted with a pen mate's tail, differed between docking length treatments and was highest in the Long/Undocked compared with the Short treatment (P<0.01), but docking length did not affect aggressive behaviour. Docking length affected the risk of a tail biting outbreak and the frequency of tail-directed behaviour in our participating herds, of which three reported a high prevalence of tail biting problems. Only the shortest docking length treatment (Short) reduced the tail biting risk, but did not completely prevent tail biting outbreaks.
猪的咬尾与一系列风险因素有关，主要涉及猪的环境。预防性断尾被广泛应用，各种实验方法表明断尾可以降低咬尾的风险。然而，断尾的长度是否会影响咬尾的爆发率，以及短尾会如何影响猪的社交行为，这些问题研究较少。本研究旨在调查三种不同的断尾长度（在断尾时测量），以及保留完整的尾巴（短尾：2.9 厘米；中尾：5.7 厘米；长尾：7.5 厘米；未断尾）如何影响具有相同断尾长度处理的育肥猪的咬尾风险和针对其他育肥猪的行为。每周对尾巴损伤进行评分，并在引入育肥猪栏后以及在发生咬尾或屠宰之前对栏位水平的行为进行评分。来自四个商业养殖场（258 窝）的猪进入了研究。在猪进入育肥区并开始收集数据之前，由于育肥区出现了咬尾现象，一些猪被排除在外。尾部咬噬的风险在处理之间存在显著差异（P=0.001），与未断尾（P<0.001）和中尾（P<0.05）相比，短尾的尾部咬噬风险降低，且受养殖场的影响（P<0.001）。由于长尾和未断尾处理的代表性较低，尤其是在未断尾处理中，长尾和未断尾处理的围栏被合并进行行为分析。尾巴接触的概率（猪与围栏同伴的尾巴互动的概率）因断尾长度处理而异，与短尾处理相比，长尾/未断尾处理的尾巴接触概率最高（P<0.01），但断尾长度不影响攻击性行为。断尾长度影响了参与养殖场的咬尾爆发风险和尾巴指向行为的频率，其中三个养殖场报告了较高的咬尾问题发生率。只有最短的断尾长度处理（短尾）降低了咬尾风险，但并未完全防止咬尾爆发。
