Department of Veterinary and Animal Sciences, University of Copenhagen, Groennegaardsvej 8, Frederiksberg, Copenhagen1870, Denmark.
SEGES, Danish Pig Research Centre, Agro Food Park 15, Aarhus8200, Denmark.
Animal. 2020 Oct;14(10):2159-2166. doi: 10.1017/S1751731120001081. Epub 2020 May 18.
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.
仔猪在哺乳期前出现咬尾现象，但有关哺乳期内尾巴损伤和随着时间的推移尾巴损伤发展的文献很少，特别是对于未去势的仔猪。我们评估了丹麦一家商业猪场哺乳期和断奶期未去势仔猪的尾巴损伤发生率，并研究了断奶前后仔猪尾巴病变的内在关联性。从出生到 9 周龄（w9），对 51 头散栏母猪的 741 头未去势仔猪进行个体标记和跟踪。在哺乳期的 w1 和 w4 时对尾巴损伤进行评分，断奶后每周（平均断奶年龄 30 天）在 w6 至 w9 进行评分。使用广义混合模型在猪水平上研究了断奶前后尾巴损伤的内在关联性。在断奶前，尾巴损伤已经很普遍。在哺乳期，w1 时尾巴损伤的发生率为 5%，w4 时为 42%，最常见的损伤评分是“浅表损伤”（66.7%，评分 1；断奶前方案：0=无损伤，3=尾巴伤口）。断奶后，45%的猪在四次评估中有至少一次尾巴损伤，16.7%的猪在至少两次评估中有尾巴损伤。大多数病变是“轻微划痕”（34.2%，评分 1；断奶后方案：0=无损伤，4=伤口-坏死的尾巴末端）和“结痂伤口”（19.9%，评分 3）。病变猪的数量和伤口严重程度随着时间的推移而增加。w8（15%，P<0.001 和 <0.01）和 w9（19%，P<0.001 和 <0.001）时尾巴受伤的猪比 w6（2.7%）和 w7（5.6%）时更多。断奶前有尾巴病变的猪（w1：OR 3.0，95%CI 0.9 至 10.2；w4：OR 3.4，95%CI 2.0 至 5.8）在断奶后发生伤口的风险显著增加，并且在 w4 时有病变的猪（OR 3.0，95%CI 1.8 至 5.1）在几次评估中发生病变的风险更高。与去势公猪相比，母猪在 w1 时尾巴损伤的风险显著降低（OR 0.3，95%CI 0.1 至 0.8）。同样，母猪在断奶后发生伤口的风险显著降低（OR 0.5，95%CI 0.4 至 0.9），并且在几次评估中发生病变的风险较低（OR 0.7，95%CI 0.5 至 1.2）。我们的研究证实，尾巴损伤在哺乳期已经很普遍，并且断奶前的尾巴损伤预示着断奶后的尾巴伤口。
