Monitoring and Maintaining milking machine function
The most common reason for milking machine problems is inadequate routine maintenance of mechanical components and rubberware. A series of regular, systematic checks gives a simple method of finding problems and guiding preventative maintenance. If more than one person milks in your shed, it is important to assign these checking tasks to particular people, and ensure that the right person is alerted to any problems that are found or suspected. Daily and weekly checks should be conducted by milking staff as part of their regular list of responsibilities. The herd owner or manager or other skilled observer should do the monthly checks. Recording the results of monthly checks enables subtle changes due to wear and age to be detected more easily.
- Daily checks
- Check the air admission holes (air vents). If the air vent is blocked, the claw bowl fills with milk and leads to more cup falling, slow or incomplete milking, and difficulty removing clusters even after the vacuum is cut off. Remove any debris with the probe designed for the task. Avoid using drill bits or other tools that may enlarge the holes.
- Read the vacuum gauge. Tap the face of the gauge to ensure that the needle isn't sticking.
- Listen to pulsators. The sound of air entering the external air port should be both regular and intermittent. It should be the same sound for all pulsators.
- Watch milk entering the receival can. Flow should be even, without flooding or slugging.
- Check teats as the cups come off at the end of milking. Look for discolouration (reddish, bluish or purplish teat skin colour). Look or feel for swelling or hardness at the top, middle or end of the teats. Examine teat openings for signs of cracking, sores or teat canal lining pulled out of the opening. Observe if teats are unusually sensitive to touch.
- Check cow behaviour. Are cows nervous and uncomfortable when teatcups are put on or removed from teats, or during milking? Weekly checks
- Check for twisted liners. Align marks on mouthpiece and stem of liner, or place your thumb in each liner.
- Check liner condition. Look particularly for distortion of the mouthpiece lip or holes in the short milk tube. Split liners lead to fluid between the liner and the teatcup shell.
- Check filters on pulsator airlines especially on rotary dairies where the filters are close to the feeders.
- Listen to the regulator(s).
- Monthly checks
- Check 'effective reserve' of vacuum and regulator function. With the machine running, open one set of cups (or if more than 32 units, open two sets). If vacuum drops more than 2 kPa, then effective reserve is not adequate. During this test, check that the regulator closes or almost closes. The hiss of air entering the regulator should be greatly reduced when the cups are opened. If this does not happen, check the regulator filter and clean if necessary. If cleaning does not improve the regulator response, call your AMMTA milking machine technician.
- Measure completeness of milking and milking times. If cups are applied before milk let-down, these average milking times should be extended by approximately one minute.
- Count cup squawks and slips requiring correction by milker. A running tally over 15 minutes of milking provides a guide. To assess machine function, exclude cows with very poor udder conformation which always have cups slip.
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