如泌乳阶段的关键因素,平价和身体脂肪储备与数字垫厚度有关,然而,先前发表的研究结果之间存在差异.这项研究的目的是检查泌乳阶段的关联,体内脂肪储备,奇偶校验,在大量密集监测的奶牛中,数字垫厚度(DCT)和病变发生率。在英国的4个农场,2,352头母牛在4个时间点进行了前瞻性登记和评估;产仔前(T1-预试验),分娩后立即(T2-分娩),在泌乳早期(T3-早期)和泌乳晚期(T4-晚期)。在每个时间点记录身体状况评分,兽医评估了是否存在单一病变(单一溃疡和单一出血)和白线病变,并采取超声图像回顾性测量骨盆(BFT)区域和后左外侧爪上的数字垫的背部脂肪厚度。混合效应多变量线性回归模型,以母牛为随机效应进行拟合,以检查解释变量与DCT之间的关联。测试的解释变量是农场,奇偶校验,哺乳期,身体状况评分,BFT,高度,测量时病变的存在,泌乳早期病变的慢性,预测最大每日产奶量和产奶率在泌乳早期上升。哺乳期和农场阶段都与DCT有关,然而,存在相互作用,这种DCT变化模式取决于农场。出现了两种不同的模式;一种表明最低点发生在产卵后不久,另一个表明最低点发生在泌乳早期。背部脂肪厚度和BCS均与DCT无关。与多胎母牛相比,小母牛显示出更薄的数字垫子,然而,这种影响取决于泌乳阶段,小母牛有一个更薄的数字垫,直到哺乳晚期,到那时,DCT与多胎动物相称。测量时的鞋底病变和白线病变与DCT相关(鞋底病变;估计值:-0.07mm,95%CI:-0.14-0.00,P=0.039,白线病变;估计值:0.28mm,95%CI:0.15-0.42,P<0.001)。
Key factors such as stage of lactation, parity, and body fat reserves have been associated with the digital cushion thickness (DCT), however, there are discrepancies between the results of previously published studies. The objective of this study was to examine the association of stage of lactation, body fat reserves, parity, and lesion incidence with DCT in a large cohort of intensively monitored cows. Across 4 UK farms, 2,352 cows were prospectively enrolled and assessed at 4 time points: before calving (T1-Precalving), immediately after calving (T2-Calving), in early lactation (T3-Early), and in late lactation (T4-Late). At each time point,
BCS was recorded, the presence of sole lesions (sole ulcers and sole hemorrhage) and white line lesions was assessed by veterinarians, and an ultrasound image was taken to retrospectively measure the backfat thickness (BFT) in the pelvic region and the digital cushion on the hind left lateral claw. Mixed effects multivariable linear regression models, with the cow as a random effect, were fit to examine the association between the explanatory variables and DCT. The explanatory variables tested were farm, parity, stage of lactation,
BCS, BFT, height, the presence of a lesion at the time of measurement, the chronicity of a lesion during early lactation, the predicted maximum daily milk yield, and the rate of milk production rise in early lactation. Stage of lactation and farm were both associated with DCT; however, an interaction was present, and this DCT pattern of change was farm-dependent. Two distinct patterns emerged; one indicated the nadir to occur shortly after calving, the other indicated the nadir to occur during early lactation. Neither BFT nor
BCS were significantly associated with DCT. Heifers displayed thinner digital cushions compared with multiparous cows; however, this effect was dependent on the stage of lactation, with heifers having a thinner digital cushion up until late lactation, by which time DCT was commensurate with multiparous animals. Sole lesions and white line lesions at the time of measurement were associated with DCT (sole lesion: estimate = -0.07 mm, 95% CI = -0.14-0.00; white line lesion: estimate = 0.28 mm, 95% CI = 0.15-0.42).