Rasmussen M D, Madsen N P
Danish Institute of Agricultural Sciences, Research Centre Foulum, Tjele, Denmark.
J Dairy Sci. 2000 Jan;83(1):77-84. doi: 10.3168/jds.S0022-0302(00)74858-2.
The influence of milkline vacuum, pulsator airline vacuum, and cluster weight on complete lactation milk yield performance, teat condition, and udder health were studied in 241 cows by using three separate factorial experiments. The first experiment had milkline vacuum set at 38 and 48 kPa, pulsator airline was vacuum was set at 0 and 8 kPa above milkline vacuum, and cluster weight was 1.6 and 2.3 kg. The second experiment had milkline vacuum set at 38 and 48 kPa and cluster weight was 1.6 and 2.3 kg. The third experiment had milkline vacuum set at 32 and 42 kPa and pulsator airline vacuum 0 and 8 kPa above milk line vacuum. The first two experiments were carried out with a high-level milking and the third with a low-level milking system. The average vacuums in the short milk tube during milking for low and high milkline vacuum in the high-level system were 26 and 33 kPa, and 30 and 39 kPa for the low-level milking system, respectively. Milking at low vacuum increased the machine-on time and frequency of liner slip, decreased milk flow rate, but had no influence on teat condition and udder health. The milk yield of high producing cows with long machine-on time was reduced by 5% when milked at a low vacuum. A higher pulsator airline vacuum than milkline vacuum had no influence on milking performance. The use of the light cluster reduced machine-on time. We recommend that mean vacuum in the short milk tube should not be lower than 32 kPa.
通过三项独立的析因实验，对241头奶牛研究了奶衬真空度、脉动器空气管真空度和集乳器重量对全泌乳期产奶性能、乳头状况和乳房健康的影响。第一个实验中，奶衬真空度设定为38和48千帕，脉动器空气管真空度设定为比奶衬真空度高0和8千帕，集乳器重量为1.6和2.3千克。第二个实验中，奶衬真空度设定为38和48千帕，集乳器重量为1.6和2.3千克。第三个实验中，奶衬真空度设定为32和42千帕，脉动器空气管真空度为比奶衬真空度高0和8千帕。前两个实验采用高水平挤奶方式，第三个实验采用低水平挤奶系统。在高水平系统中，低奶衬真空度和高奶衬真空度挤奶时短奶管内的平均真空度分别为26和33千帕，在低水平挤奶系统中分别为30和39千帕。低真空度挤奶会增加机器运行时间和内衬滑脱频率，降低奶流速度，但对乳头状况和乳房健康没有影响。高产奶牛在低真空度挤奶且机器运行时间长时，产奶量会降低5%。脉动器空气管真空度高于奶衬真空度对挤奶性能没有影响。使用较轻的集乳器可减少机器运行时间。我们建议短奶管内的平均真空度不应低于32千帕。
