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• When should the cups come off?

When should the cups come off?

For a number of years there has been a perception that a moderate amount of overmilking causes few if any problems, and that overmilking is better than leaving milk behind in the udder (undermilking).

Overmilking and undermilking are equally bad and can contribute greatly to a mastitis problem.

Ideally the cups are removed from the teats as soon as the milk flow stops.  If the milking machines are operating perfectly and the vacuum at the teat end is not too high, the teats will receive very little damage if the cups are left on for up to 2 minutes after milk flow has ceased.  The longer the cups are left on, or the higher the vacuum the greater the damage will be.  This has some serious implications for the common milking systems.

Highline herring bone systems need to operate at a higher operating vacuum (usually 46 to 50 kPa) in order to lift the milk from the cow to the milkline.  Also, with many herring bone sheds the milkers are hard pressed to keep up with putting cups on the cows, loading the next platform, removing cups and teat spraying.  The result is that cows have the cups on longer and at a higher vacuum than desired.

Rotary Dairies:  Many cows finish milking part way through a platform rotation.  If the cups off person stands right at the bridge this could mean the cups are hanging on the cow for over 5 minutes.

What can be done to minimise the effects of overmilking?

Ensure the milking machines are operating correctly and the vacuum is correctly set for your setup.

Remove the milking cluster as soon after milk flow ceases as possible.

• In rotary dairies this requires the cups off person to "sweep" around the back of the platform.
• In herring bone dairies the cups are removed when the milk flow finishes and if the next platform is not ready, the cups hung up.

It would be ideal to always have sufficient staff present during milking, or to have automatic cup removers installed.  From field observations, one operator can reasonably handle 15 to 20 milking units from calving to peak production.  Even in rotary dairies there is a need for one operator per 20 milking units during this period.  In the strive for greater efficiencies many dairy workers are handling more units.  In these conditions extra care will be required to prevent problems associated with overmilking.

The addition of automatic cup removers reduces the labour requirement in the shed.  For a herring bone shed it would mean that one operator could operate 25 to 30 units comfortably.

There are numerous farmers that have achieved significant reductions in the level of clinical mastitis, BMCC and milking time by taking the cups off at the cessation of milk flow, either by the more rapid removal of the clusters or installation of cup removers.

Average Milking Times

Assuming good milk let-down and corectly adjusted milking equipment

• 95% of cows giving
• 10 litres / milking, should milk in 5 minutes ( /- 1 minute)
• 15 litres / milking, should milk in 6 minutes ( /- 1 minute)
• 20 litres / milking, should milk in 7 minutes ( /- 1 minute)

Under milking

Hand stripping of at least 10 cows after milking should give less than an average of 250 ml/cow. If more than 500 ml/cow is collected, there is a significant problem with under milking.

If your average cups on time varies greatly from these recommendations, adjustments to either the milking machines or milking technique are required.

This article has been modified from the Countdown Downunder Farm Guidelines.