Published online by Cambridge University Press: 01 June 2009
Changes were made in milking conditions and vacuum levels to assess optimum parameters for hydraulic milking. A randomized block design was used for the trial, each result being the mean of data from four cows. The results confirmed that faster milking occurred at 50 kPa vacuum (pulsation and milkline) and showed that high vacuum levels created within the liner could be prevented by providing a higher vacuum to the pulsation chamber than the milkline (differential vacuum) without substantially reducing milking performance. The stimulation provided by hydraulic milking may be important in achieving rapid milking in the absence of udder preparation. Lipolysis of milk fat was reduced by hydraulic milking as was milk foam in the recorder jar, particularly when no air was admitted to the claw.