Abstract：
BACKGROUND: Digital dermatitis (DD) is a contagious bovine foot disease causing painful lesions, lameness, and reduced animal welfare. Previous studies indicate a complex aetiology of the disease. The aim of this study was to compare DD negative and DD positive herds to identify factors associated with DD in Norwegian dairy herds by analysing data obtained in a questionnaire and data recorded in the Norwegian Dairy Herd Recording System (NDHRS). The questionnaire was e-mailed to the owners of all 380 herds recorded with DD in 2019 and to 1530 randomly selected herds with no recordings of DD. Altogether 559 dairy herds were included in the final study population, of which 113 was classified as DD positive (≥ one cow recorded with DD in NDHRS) and 446 as DD negative. When stratified by housing system, the ratio between DD positive and negative herds was 108/281 in free stalls and 5/165 in tie stalls. Multilevel logistic regression was used to model the association between potential risk factors and variables related to the detection and diagnosis of DD, and the outcome in the free-stall population. Geographical area (county) was included in the model as a random effect.
RESULTS: In the final study population 108/113 (96%) of the DD positive herds were housed in free stalls versus 5/113 (4%) in tie stalls. The free-stall herds\' DD status was associated with purchase of cattle during the last 5 years (baseline: 0 animals, OR = 2.30 for category 12-27 animals, OR = 4.34 for 28-52 animals, and OR = 5.39 for ≥ 53 animals). The DD status was also associated with claw trimming frequency (Baseline: 1 < 2/year, OR = 0.41 for category < 1/year, and OR = 4.09 for ≥ 3/year), whether the claw trimming was done by a certified professional trimmer or not (baseline: ≤ 90% of the cows, OR = 3.98 for category ≥ 90% of the cows), cleaning of feet in the chute before trimming (baseline: no cleaning, OR = 1.98 for category cleaning), and alley flooring (baseline: slatted floor, OR = 2.36 for category solid floor).
CONCLUSIONS: Digital dermatitis was far more frequent in Norwegian dairy herds housed in free stalls versus those housed in tie stalls. In the free-stall herds purchase of cattle, increasing trimming frequency, use of certified professional trimmer, cleaning of the feet in the chute, and solid flooring in the alleys were associated with increased odds of recorded DD.
RESULTS: In the final study population 108/113 (96%) of the DD positive herds were housed in free stalls versus 5/113 (4%) in tie stalls. The free-stall herds\' DD status was associated with purchase of cattle during the last 5 years (baseline: 0 animals, OR = 2.30 for category 12-27 animals, OR = 4.34 for 28-52 animals, and OR = 5.39 for ≥ 53 animals). The DD status was also associated with claw trimming frequency (Baseline: 1 < 2/year, OR = 0.41 for category < 1/year, and OR = 4.09 for ≥ 3/year), whether the claw trimming was done by a certified professional trimmer or not (baseline: ≤ 90% of the cows, OR = 3.98 for category ≥ 90% of the cows), cleaning of feet in the chute before trimming (baseline: no cleaning, OR = 1.98 for category cleaning), and alley flooring (baseline: slatted floor, OR = 2.36 for category solid floor).
CONCLUSIONS: Digital dermatitis was far more frequent in Norwegian dairy herds housed in free stalls versus those housed in tie stalls. In the free-stall herds purchase of cattle, increasing trimming frequency, use of certified professional trimmer, cleaning of the feet in the chute, and solid flooring in the alleys were associated with increased odds of recorded DD.
摘要：
背景：数字皮炎（DD）是一种传染性牛足病，会引起疼痛性病变，跛行，减少动物福利。先前的研究表明该疾病的病因复杂。这项研究的目的是通过分析问卷中获得的数据和挪威奶牛群记录系统（NDHRS）中记录的数据，比较DD阴性和DD阳性牛群，以确定与挪威奶牛群DD相关的因素。问卷通过电子邮件发送给2019年用DD记录的所有380个牛群的所有者，以及1530个随机选择的牛群，没有DD记录。最终研究人群中总共包括559个奶牛群，其中113只被归类为DD阳性(≥1头牛在NDHRS中记录为DD)，446只被归类为DD阴性。当按住房系统分层时，在免费摊位中，DD阳性和阴性牛群的比率为108/281，在领带摊位中为5/165。采用多水平logistic回归对潜在危险因素和与DD检测诊断相关的变量之间的关联进行建模,以及自由摊位人口的结果。地理区域（县）作为随机效应包含在模型中。
结果：在最终研究中，有108/113（96％）的DD阳性牛群被安置在免费摊位中，而5/113（4％）则被安置在领带摊位中。在过去5年中，免费摊位牧群的DD状态与购买牛有关(基线：0只动物，对于12-27类动物，OR=2.30，28-52只动物的OR=4.34，≥53只动物的OR=5.39)。DD状态也与爪子修剪频率相关(基线：1<2/年，对于类别<1/年，OR=0.41，≥3/年的OR=4.09)，爪修剪是否由经过认证的专业修剪机完成(基线:≤90%的奶牛，类别≥90%的奶牛的OR=3.98)，修剪前清洁滑槽中的脚(基线:不清洁,类别清洁的OR=1.98)，和小巷地板(基线:板条地板，对于类别实心地板，OR=2.36)。
结论：在免费摊位饲养的挪威奶牛群中，数字皮炎的发生率要高得多。在自由摊位的牛群购买中，增加微调频率，使用经过认证的专业修剪器，清理滑槽里的脚,小巷中坚固的地板与记录的DD的几率增加有关。
结果：在最终研究中，有108/113（96％）的DD阳性牛群被安置在免费摊位中，而5/113（4％）则被安置在领带摊位中。在过去5年中，免费摊位牧群的DD状态与购买牛有关(基线：0只动物，对于12-27类动物，OR=2.30，28-52只动物的OR=4.34，≥53只动物的OR=5.39)。DD状态也与爪子修剪频率相关(基线：1<2/年，对于类别<1/年，OR=0.41，≥3/年的OR=4.09)，爪修剪是否由经过认证的专业修剪机完成(基线:≤90%的奶牛，类别≥90%的奶牛的OR=3.98)，修剪前清洁滑槽中的脚(基线:不清洁,类别清洁的OR=1.98)，和小巷地板(基线:板条地板，对于类别实心地板，OR=2.36)。
结论：在免费摊位饲养的挪威奶牛群中，数字皮炎的发生率要高得多。在自由摊位的牛群购买中，增加微调频率，使用经过认证的专业修剪器，清理滑槽里的脚,小巷中坚固的地板与记录的DD的几率增加有关。
