Department of Veterinary Population Medicine, University of Minnesota, St. Paul 55108.
Department of Large Animal Clinical Sciences, University of Florida, Gainesville 32610.
J Dairy Sci. 2020 Apr;103(4):3401-3413. doi: 10.3168/jds.2019-17252. Epub 2020 Feb 11.
The objectives of this study were to evaluate the association between hoof lesions and fertility in dairy cows. Lactating Jersey cows (n = 1,639) were enrolled at 20 ± 3 d in milk (D20), examined and treated for presence of hoof lesions (HL), and evaluated for body condition score (BCS). Afterward, they were managed according to standard farm procedures, including estrus detection and presynchronization and a 5 d Cosynch-72 protocol for cows that failed to show estrus. Ovaries were scanned at 27 and 41 ± 3 d in milk, and cows with a corpus luteum greater than 20 mm on at least 1 exam were considered cyclic. At 120 ± 3 d in milk (D120), cows were re-examined for HL and BCS. Cows were classified at D20 according to HL status as healthy (n = 1,197) or having HL (n = 429), and according to HL category as healthy (n = 1,197) or having a sole hemorrhage (n = 280), noninfectious HL (sole ulcer, toe ulcer, or white line disease; n = 113), or infectious HL (digital dermatitis and foot rot; n = 36). Cows with HL at D20 had reduced odds of being cyclic (38.3 vs. 51.9%) and a longer interval from calving to first service (58 vs. 51 d) compared with healthy cows. Cows with infectious HL at D20 had reduced odds of pregnancy to first service (16.7 vs. 38.3%) compared with healthy cows. Cows with sole hemorrhage at D20 were more likely to lose pregnancies between d 32 and 64 after the first service postpartum compared with healthy cows (10.5 vs. 5.2%). Cows with sole hemorrhage at D20 had a smaller hazard of pregnancy (67.9 vs. 75.5%) at 150 d in milk and more days open (88 vs. 77d) compared with healthy cows. To assess the relationship between the development of HL and fertility, cows were classified as healthy (no HL at D20 and D120; n = 308), cured (any HL at D20 and no HL at D120; n = 72), new HL (no HL at D20 and any HL at D120; n = 597), and chronic (any HL at D20 and D120; n = 226). Sole hemorrhage accounted for 93% of new HL. The proportions of cows with HL at D20 and D120 were 26.9 and 68.4%, respectively. We found no evidence for a difference in pregnancy hazard at 150 d in milk between cows that remained healthy (n = 308) and cows that developed new HL (n = 597). Hoof lesions at D20, but not new HL, were associated with decreased odds of cyclicity, longer interval from calving to first service postpartum, and reduced pregnancy hazard in Jersey cows. The effect of an HL diagnosis in early lactation and management to reduce chronic HL in dairy cows warrants further investigation.
本研究的目的是评估奶牛蹄病与繁殖力之间的关系。在泌乳 20 ± 3 天（D20）时，纳入泌乳泽西奶牛（n = 1639），检查并治疗蹄病（HL），评估体况评分（BCS）。此后，根据标准农场程序进行管理，包括发情检测和同期发情以及对未发情的奶牛进行 5 d Cosynch-72 方案。在 27 和 41 ± 3 天泌乳时扫描卵巢，至少有 1 次检查中黄体大于 20 mm 的奶牛被认为是有循环的。在 120 ± 3 天泌乳（D120）时，奶牛重新检查 HL 和 BCS。奶牛根据 D20 的 HL 状态分为健康（n = 1197）或有 HL（n = 429），根据 HL 类别分为健康（n = 1197）或有蹄底出血（n = 280）、非传染性 HL（蹄溃疡、趾溃疡或白线病；n = 113）或传染性 HL（趾间皮炎和腐蹄病；n = 36）。与健康奶牛相比，D20 时患有 HL 的奶牛发情的可能性降低（38.3% vs. 51.9%），产后首次配种的间隔时间延长（58 天 vs. 51 天）。D20 时患有传染性 HL 的奶牛首次配种的妊娠率降低（16.7% vs. 38.3%）。与健康奶牛相比，D20 时患有蹄底出血的奶牛在产后首次配种后 32-64 天之间的妊娠损失几率更高（10.5% vs. 5.2%）。D20 时患有蹄底出血的奶牛在 150 天泌乳时的妊娠几率（67.9% vs. 75.5%）较低，开放天数（88 天 vs. 77 天）较长。为了评估 HL 发展与繁殖力之间的关系，奶牛被分为健康（D20 和 D120 时无 HL；n = 308）、治愈（D20 时有 HL，D120 时无 HL；n = 72）、新发 HL（D20 时无 HL，D120 时 HL；n = 597）和慢性 HL（D20 和 D120 时均有 HL；n = 226）。蹄底出血占新发 HL 的 93%。D20 和 D120 时 HL 的比例分别为 26.9%和 68.4%。我们发现，在 150 天泌乳时，保持健康（n = 308）和新发 HL（n = 597）的奶牛之间的妊娠几率没有差异。D20 时的蹄病，而不是新发 HL，与奶牛的发情率降低、产后首次配种间隔时间延长和妊娠几率降低有关。在早期泌乳时 HL 诊断和减少奶牛慢性 HL 的管理对泽西奶牛的繁殖力的影响值得进一步研究。
