Department of Biological Systems Engineering, University of Wisconsin-Madison, Madison 53706.
Business Economics Group, Wageningen University, 6706 KN, the Netherlands.
J Dairy Sci. 2021 Jun;104(6):6820-6831. doi: 10.3168/jds.2020-19418. Epub 2021 Mar 25.
The objective of this study was to compare a vacuum control system that increases milking system vacuum during the peak flow period of milking to conventional constant vacuum control technology regarding its effect on milk flowrate and milking duration. Further objectives were to study the effects of flow-controlled vacuum on milking parlor performance. An observational study was conducted on a commercial dairy farm milking from 848 to 896 cows per day over the study period using a 60-stall rotary milking parlor. The flow-controlled vacuum control system was applied for 3 wk. Milking performance and teat condition were compared with 3-wk periods prior and subsequent to the test period using conventional vacuum control. Statistical analysis was performed assuming a cross-sectional study design during each period. Flow-controlled vacuum increased peak milk flowrate by 12% and increased average milk flowrate by 4%. The decrease in individual cow milking duration was proportional to milk yield per milking. Postmilking teat condition was good during the entire study period. The occurrence of rough teat ends was slightly reduced during the flow-controlled vacuum period with no meaningful difference in the occurrence of teats with blue color, palpable rings, or petechia. The combination of reduced vacuum during the low flow period of milking and the decrease in milking duration are likely factors that are protective of teat tissues. Bioeconomic modeling of the use of flow-controlled vacuum on the performance of rotary milking parlors, using the data that were collected during the study, showed that the reduction in milking duration of individual cows allows a higher rotary parlor speed. Modeled parlor throughput increased by 5.0% to 419 cows/h, 6.8% to 407 cows/h, and 4.2% to 326 cows/h when 80%, 95%, and 99% of the cows were finished milking at the end of the rotation for a 60-stall parlor. Model results showed that increased parlor throughput resulted in increased labor efficiency, reduced labor costs for milking, and a positive benefit-cost ratio on the investment for all but the smallest herd and parlor sizes considered.
本研究旨在比较一种在挤奶高峰期增加挤奶系统真空度的真空控制系统与传统恒压真空控制技术对奶流量和挤奶时间的影响。进一步的目标是研究流量控制真空对挤奶厅性能的影响。在研究期间，对一个商业奶牛场进行了一项观察性研究，每天有 848 至 896 头奶牛在一个 60 位旋转挤奶厅挤奶。该流量控制真空控制系统应用了 3 周。使用传统真空控制，在测试期间前后的 3 周内，对挤奶性能和乳头状况进行了比较。在每个时期，假设为横截面研究设计进行了统计分析。流量控制真空将峰值奶流量提高了 12%，平均奶流量提高了 4%。每头奶牛挤奶时间的减少与产奶量成比例。整个研究期间，挤奶后乳头状况良好。在流量控制真空期间，粗糙乳头末端的发生略减少，而蓝色乳头、可触环或瘀点的发生没有明显差异。在挤奶的低流量期降低真空度和减少挤奶时间的组合可能是保护乳头组织的因素。使用在研究期间收集的数据，对旋转挤奶厅使用流量控制真空的性能进行生物经济建模，结果表明，每头奶牛挤奶时间的减少允许更高的旋转挤奶厅速度。当 80%、95%和 99%的奶牛在 60 位挤奶厅的旋转结束时完成挤奶时，模型中的挤奶厅吞吐量分别增加了 5.0%、6.8%和 4.2%，达到 419 头/小时、407 头/小时和 326 头/小时。模型结果表明，增加挤奶厅吞吐量导致劳动效率提高，挤奶劳动力成本降低，并且对投资的收益成本比为正，除了考虑到的最小牛群和挤奶厅规模。
