Tail-biting occurs pre-weaning, but literature on tail damage during lactation and on the development of damage over time is sparse, especially for non-docked piglets. We assessed the prevalence of tail damage in non-docked piglets in a commercial Danish piggery during the lactation and weaning period, and investigated the within-animal association of tail lesions pre- and post-weaning. Non-docked piglets (n = 741) from 51 loose-housed sows were individually marked and tracked from birth to 9 weeks (w9) of age. Tail damage was scored during lactation at w1 and w4, and once a week post-weaning (average weaning age 30 days) at w6 to w9. The within-animal association of tail damage before and after weaning was investigated at pig level using generalized mixed models. Tail damage was prevalent already pre-weaning. During the lactation period, the prevalence of tail lesions was 5% at w1 and 42% at w4, with the most prevalent score being ‘superficial damages’ (66.7%, score 1; pre-weaning scheme: 0 = no damage, 3 = tail wound). Post-weaning, 45% of pigs had a tail lesion at least once over the four assessments, with 16.7% of pigs having a tail lesion at least at two assessments. The majority of lesions were ‘minor scratches’ (34.2%, score 1; post-weaning scheme: 0 = no damage, 4 = wound – necrotic tail end) and a ‘scabbed wound’ (19.9%, score 3). The number of pigs with lesions as well as wound severity increased over time. More pigs had a tail wound at w8 (15%, P < 0.001 and < 0.01) and w9 (19%, P < 0.001 and < 0.001) compared to w6 (2.7%) and w7 (5.6%). Pigs with tail lesions pre-weaning (w1: OR 3.0, 95% CI 0.9 to 10.2; w4: OR 3.4, 95% CI 2.0 to 5.8) had a significantly higher risk of having a wound post-weaning, and pigs with lesions at w4 additionally were at a higher risk (OR 3.0, 95% CI 1.8 to 5.1) of having a lesion over several assessments. Females compared to castrated males had a significantly lower risk of having tail lesions at w1 (OR 0.3, 95% CI 0.1 to 0.8). Similarly, females were at a significantly lower risk (OR 0.5, 95% CI 0.4 to 0.9) of having a wound post-weaning, and tended to have a lower risk of having lesions over several assessments (OR 0.7, 95% CI 0.5 to 1.2). Our study confirmed that tail damage is prevalent already during the lactation period, and that pre-weaning tail damage is predictive of tail wounds post-weaning.

断奶前会咬咬尾巴，但是关于哺乳期尾巴损伤以及随时间推移损伤发展的文献很少，特别是对无坞仔猪。我们评估了泌乳和断奶期间丹麦商业猪非对接仔猪尾巴损伤的患病率，并研究了断奶前后仔猪尾部病变的动物内关联。无坞仔猪（n分别对51头散养母猪中的741头进行了标记，并追踪了从出生到9周（w9）的年龄。在哺乳期第1周和第4周，以及断奶后每周一次（平均断奶年龄30天）在第6周至第9周对尾巴损伤进行评分。使用广义混合模型在猪水平上研究断奶前后断尾的动物内关联。断奶很普遍，已经断奶。在哺乳期，尾部病变的患病率在第1周时为5％，在第4周时为42％，最普遍的得分是“表面损伤”（66.7％，得分1；断奶前方案：0 =无损伤，3 =尾巴伤口）。断奶后，在四个评估中至少有45％的猪出现尾巴病变，两次评估中至少有16.7％的猪有尾巴病变。多数病变为“轻微划痕”（34.2％，评分为1；断奶后方案：0 =无损伤，4 =伤口–坏死的尾端）和“擦伤伤口”（19.9％，得分3）。随着时间的流逝，具有病变的猪的数量以及伤口的严重程度都在增加。第8周时，有更多的猪尾巴受伤（15％，P <0.001和<0.01）和w9（19％，P<0.001和<0.001），而w6（2.7％）和w7（5.6％）。断奶前有尾部病变的猪（w1：OR 3.0，95％CI 0.9到10.2； w4：OR 3.4，95％CI 2.0到5.8）断奶后伤口受伤的风险显着更高，并且在此外，w4在多个评估中有病变的风险较高（OR 3.0，95％CI 1.8至5.1）。与cast割的男性相比，女性在w1出现尾部病变的风险显着降低（OR 0.3，95％CI 0.1至0.8）。同样，女性在断奶后有伤口的风险显着较低（OR 0.5，95％CI 0.4至0.9），在多次评估中，患病的风险也较低（OR 0.7，95％CI 0.5至0.9）。 1.2）。我们的研究证实，泌乳期尾巴损伤已经很普遍，