Department of Veterinary Population Medicine, University of Minnesota, St. Paul 55108.
Department of Veterinary Population Medicine, University of Minnesota, St. Paul 55108.
J Dairy Sci. 2022 Jul;105(7):6164-6174. doi: 10.3168/jds.2021-21694. Epub 2022 May 20.
This observational cohort study enrolled cows from 7 freestall dairy herds in Minnesota and Wisconsin. The objective was to estimate the causal role of hyperketonemia on new sole ulcer and white line hoof lesions (SUWL). Multiparous cows were enrolled at the time of their precalving hoof trim, at the end of their previous lactation. Enrolled cows were hoof trimmed twice: precalving between 90 to 21 d before calving (n = 2,037), and postcalving between 21 to 150 d after calving (n = 1,408). We trained 7 commercial hoof trimmers, employed by the farms, in lesion identification to standardize lesion recording. Hoof trimmers conducted therapeutic trimming as well as diagnosing and treating lesions. After parturition, cows between 3 and 16 d in milk were tested once weekly for hyperketonemia using a hand-held ketone meter. Farm staff and research personnel conducted the β-hydroxybutyrate (BHB) testing. Cows were classified as hyperketonemic (HYK+) if they had a blood BHB ≥1.2 mmol/L or hyperketonemia-negative (HYK-) if blood BHB <1.2 mmol/L. At the precalving hoof trim, 15.6% of cows trimmed had a lesion and 1.9% of cows had a SUWL; thus, cows with a SUWL were excluded from further analysis (n = 38). At the postcalving hoof trim, 25.8% of cows trimmed had a hoof lesion, and 3.6% of cows had a SUWL. The most prevalent lesions at the pre- and postcalving hoof trims were digital dermatitis and corkscrew lesions. The incidence of hyperketonemia among cows was 21.1% (421/1,999) and the incidence on farms ranged from 5.7 to 29.1%. After excluding cows due to being hoof trimmed outside our designated window, the multilevel logistic regression model for the odds of SUWL at the postcalving hoof trim included 1,209 cows (HYK+ = 257/1,209; SUWL = 42/1,209). The odds of having SUWL in HYK+ was 0.66 (95% confidence interval: 0.29, 1.49) times the odds of that for HYK- cows. For cows diagnosed with a lesion (digital dermatitis, corkscrew, toe, foot rot, or other lesion) at their precalving hoof trim (n = 199), the odds of having SUWL for HYK+ cows were 0.43 (95% confidence interval: 0.05, 3.92) times the odds of that for HYK- cows. The wide range of compatible causal estimates suggest that hyperketonemia likely has a limited role in the development of SUWL in cows with or without a hoof lesion precalving. Future research should investigate other transition period factors such as inflammation or structural changes to the foot that may have a causative role in the development of SUWL.
本观察性队列研究纳入了明尼苏达州和威斯康星州 7 个无卧床奶牛场的奶牛。目的是评估酮血症对新的蹄底溃疡和白线 hoof lesions（SUWL）的因果作用。在产前修剪蹄子时招募多胎奶牛，在上一个泌乳期末。入组奶牛进行了两次蹄修剪：产前 90 至 21 天（n = 2037）和产后 21 至 150 天（n = 1408）。我们培训了 7 名受农场雇佣的商业蹄修剪师，以标准化病变记录。蹄修剪师进行了治疗性修剪以及诊断和治疗病变。产后 3 至 16 天，使用手持式酮体计每周对奶牛进行一次酮血症检测。农场工作人员和研究人员进行了β-羟基丁酸（BHB）检测。如果奶牛血液 BHB≥1.2mmol/L，则将其归类为高酮血症（HYK+），如果血液 BHB<1.2mmol/L，则归类为低酮血症（HYK-）。在产前蹄修剪时，15.6%修剪的奶牛有病变，1.9%的奶牛有 SUWL；因此，患有 SUWL 的奶牛被排除在进一步分析之外（n = 38）。产后蹄修剪时，25.8%修剪的奶牛有蹄病变，3.6%的奶牛有 SUWL。产前和产后蹄修剪中最常见的病变是趾间皮炎和螺旋状病变。奶牛酮血症的发生率为 21.1%（421/1999），农场的发生率从 5.7%到 29.1%不等。排除因在我们指定的窗口之外进行蹄修剪而被淘汰的奶牛后，产后蹄修剪时发生 SUWL 的多水平逻辑回归模型包括 1209 头奶牛（HYK+ = 257/1209；SUWL = 42/1209）。患有 HYK+的奶牛发生 SUWL 的几率是 HYK-奶牛的 0.66（95%置信区间：0.29，1.49）倍。对于在产前蹄修剪时被诊断出有病变（趾间皮炎、螺旋状、脚趾、腐蹄病或其他病变）的奶牛（n = 199），患有 HYK+的奶牛发生 SUWL 的几率是 HYK-奶牛的 0.43（95%置信区间：0.05，3.92）倍。范围广泛的相容因果估计表明，高酮血症可能在有或没有产前蹄病变的奶牛中对 SUWL 的发展起有限作用。未来的研究应调查其他过渡期因素，如炎症或足部结构变化，这些因素可能在 SUWL 的发展中起因果作用。
