Machine milking-induced changes in teat tissue condition, such as congestion and edema, have been associated with teat canal openness, penetrability, and thus susceptibility to new intramammary infections and diminished animal well-being. The primary objective of this study was to investigate the association of teat-end shape and machine milking-induced short-term changes in teat tissue condition. Our secondary objective was to study the association of udder-level milking characteristics and short-term changes. Data from 125 Holstein cows were analyzed in a longitudinal prospective cohort study. Cows were housed in freestall pens with sand bedding, fed a total mixed ration, and milked 3 times per day. Teat-end shape was classified into 3 categories: pointed, flat, and round. Udder-level milking characteristics were obtained from electronic on-farm milk meters. Short-term changes in teat tissue condition after machine milking were assessed visually. Multivariable generalized mixed model analysis showed an association between teat-end shape and short-term changes. Compared with teats with round teat-end shape, the odds ratio (95% confidence interval) for short-term changes was 1.68 (0.53–5.31) and 0.03 (0.004–0.19) in teats with pointed and flat teat-end shape, respectively. There was an association between milking characteristics and short-term changes such that higher milk flow rate during the first 15 s of milking decreased the likelihood of short-term changes. The adjusted probability of short-term changes for a milking observation of a mid-lactation cow and an average first 15-s milk flow rate of 0.5 and 1.5 kg/min was 53.0% (42.8–63.8) and 32.9% (15.2–57.3), respectively. Our results suggest that teat-end shape may be one of the risk factors that contribute to machine milking-induced short-term changes. Milking characteristics (e.g., first 15-s milk flow rate) may have the potential as a measure to indirectly monitor teat tissue changes associated with machine milking on a daily basis, though further research is needed to validate this hypothesis and to establish thresholds that could serve as on-farm guidelines.

挤奶导致的挤奶和乳头肿胀等水肿，与挤奶管的开放性，穿透性有关，因此易患新的乳内感染并降低动物的健康水平。这项研究的主要目的是调查奶头末端形状与挤奶诱导的奶头组织状况短期变化之间的关系。我们的次要目标是研究乳房水平挤奶特征与短期变化之间的关系。在纵向前瞻性队列研究中分析了来自125头荷斯坦奶牛的数据。牛被放进带有砂层的弗里斯托尔圈舍中，以总定量配给饲料，并且每天挤奶3次。奶头形状分为三类：尖头，扁平和圆形。从电子农场牛奶计获得乳房水平的挤奶特性。目视评估机器挤奶后奶头组织状况的短期变化。多变量广义混合模型分析表明，奶头形状和短期变化之间存在关联。与圆形奶头末端形状的奶头相比，尖头奶嘴和扁平奶头形状的奶头短期变化的优势比（95％置信区间）分别为1.68（0.53–5.31）和0.03（0.004–0.19）。 。挤奶特性与短期变化之间存在关联，因此在挤奶的前15 s内较高的牛奶流速降低了短期变化的可能性。泌乳中期奶牛观察到的短期变化的经调整的概率以及头15 s的平均最初15 s牛奶流量分别为0.5和1.5 kg / min分别为53.0％（42.8–63.8）和32.9％（15.2–57.3） ）， 分别。我们的结果表明，奶头形状可能是导致挤奶引起的短期变化的危险因素之一。挤奶特性（例如，最初的15 s牛奶流量）可能具有作为每天间接监测与机器挤奶相关的奶头组织变化的措施的潜力，尽管还需要进一步的研究来验证这一假设并建立阈值，充当农场指南。我们的结果表明，奶头形状可能是导致挤奶引起的短期变化的危险因素之一。挤奶特性（例如，最初的15 s牛奶流量）可能具有作为每天间接监测与机器挤奶相关的奶头组织变化的措施的潜力，尽管还需要进一步的研究来验证这一假设并建立阈值，充当农场指南。我们的结果表明，奶头形状可能是导致挤奶引起的短期变化的危险因素之一。挤奶特征（例如，最初的15 s牛奶流量）可能具有作为每天间接监测与机器挤奶相关的奶头组织变化的措施的潜力，尽管还需要进一步的研究来验证这一假设并建立阈值，充当农场指南。