The milking characteristics obtained with the four configurations of milking units are presented in Table 2. Altering the vacuum level at the teat-end or reducing vacuum loss in a milking system had no significant effect on milk yield. When the LMT bore was increased from 13.5 mm to 16 mm milking vacuum was increased by 2kPa with 4x1 pulsation during simulation tests. In the milking trial this increase in milking vacuum reduced the milking time by 40 seconds per cow, and increased both the average and peak milk flowrate (P<0.0001). With alternate pulsation the teat end vacuum increased from 35 kPa to 38 kPa when the LMT was increased from 13.5 mm bore to 16 mm, this reduced the milking time by 36 seconds per cow. The milking characteristics were similar when simultaneous pulsation and a 13.5 mm LMT were compared to alternate pulsation and 16 mm LMT.

Table 2. Milking characteristics recorded with four milking units calibrated with a flow simulator at 4l/min.