Department of Large Animal Clinical Sciences, Michigan State University, East Lansing 48824.
Department of Sociology, Syracuse University, Syracuse, NY 13244.
J Dairy Sci. 2019 Mar;102(3):2544-2550. doi: 10.3168/jds.2018-14943. Epub 2019 Jan 11.
The objective of this study was to determine the herd-level variables that were associated with total stimulation time during the premilking routine in 64 Michigan dairy herds. The mean herd size was 452 cows (range = 59 to 2,771 cows). For each herd, surveys were administered to producers to gather mastitis management practices and attitudes. Additionally, milking protocols were observed and milk flow dynamics were measured by use of digital vacuum recorders. Backward multivariate regression analysis was used to determine which of 47 herd-level milking and management variables were associated with mean total stimulation time. Mean total stimulation time was 14.2 s (range = 2.4-40.8 s) and was positively associated with increasing latency period (time interval between first stimulation and cluster attachment). Total stimulation time was negatively associated with greater herd size and number of visits to each cow in the premilking routine. In summary, increased stimulation time is more likely in herds that foster a lower sense of urgency of cow throughput during milking, as evidenced by a positive association with longer latency periods and fewer preparation visits per cow. Tactile stimulation is critical for efficient milk ejection; if inadequate, cows are at greater risk of delayed milk ejection and bimodal milk flow, which in turn has been associated with teat congestion and reduced milk flow. This study offers insight as to some of the herd factors that may be limiting adequate tactile stimulation.
本研究旨在确定与 64 个密歇根州奶牛场挤奶前常规操作中总刺激时间相关的畜群水平变量。平均畜群规模为 452 头奶牛（范围=59 至 2771 头）。对每个畜群，对生产者进行了调查，以收集乳腺炎管理实践和态度。此外，观察了挤奶方案并使用数字真空记录仪测量了奶流动力学。使用多元回归分析来确定 47 个畜群水平挤奶和管理变量中哪些与平均总刺激时间相关。平均总刺激时间为 14.2 秒（范围=2.4-40.8 秒），与潜伏期（第一次刺激与乳区附着之间的时间间隔）增加呈正相关。总刺激时间与畜群规模的增加和挤奶前常规操作中每头牛的访问次数呈负相关。总之，在挤奶过程中促进奶牛通过速度感较低的畜群中，刺激时间更有可能增加，这与较长的潜伏期和每头牛的准备访问次数较少呈正相关。触觉刺激对有效挤奶至关重要；如果不足，奶牛更有可能出现挤奶延迟和双峰奶流，这反过来又与乳头充血和奶流减少有关。本研究提供了一些关于可能限制充分触觉刺激的畜群因素的见解。
