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How pulsation and vacuum differ in automated milking systems

Kaden Schvaneveldt for Progressive Dairy Published on 30 August 2019
pulsation and vacuum components attached to each inflation,

Milk yields are maximized when calm cows are milked with a consistent routine from one milking to the next and from one milker to the next.

The pulsation ratio or vacuum of a milking machine affects milk flow and milking time, and has also been reported to influence teat condition and somatic cell count (SCC).



There are important differences between conventional and robotic milking systems when it comes to pulsation ratios and vacuum time on cows.

In large conventional milking parlours, it’s not uncommon to encounter overmilking because some teats empty faster than others.

You can see cows riding on a rotary for more than two minutes after a milking is completed and the unit has been detached while other cows are being milked until the very end of the turn.

Automated milking systems allow us to make vacuum and pulsation changes for individual cows or virtual groups of cows through innovative and intuitive software.

Cows are identified as they enter the milking robot, and from there the software adjusts the settings to the individual or herd.


It is important these adjustments be made by those with manufacturer-provided training, as any time changes are made to vacuum or pulsation, the settings need to be checked and verified.

Cows should be monitored for comfort during the milking process. Also, the operator should check teats and teat ends for ringing or hyperkeratosis.

It is a good idea to do this before and after any changes to see if issues are improving or worsening. Routine vacuum and pulsation checks should be done with every robot maintenance review.

The pulsators in a Lely robot are designed with four separate ports, one for each teat. Each port has a hose that goes to the inflation. This allows operators to make changes in the software that were previously only available by making a hardware change in a parlour.

For example, robot operators can change pulsation at the push of a button, from a side-to-side motion to a front-to-back motion or even to a circular motion.

In a traditional parlour, an air fork on top of the claw would need to be changed to go from side to side to front to back or vice versa.


With robots, there is also a vacuum shut-off valve for each teat. This allows robot operators to take an inflation off each teat as it is done being milked. Based on previous milkings, the robot knows which teat requires the longest time to milk and will attach to that teat first to improve efficiency.

In a parlour, there is typically only one vacuum shut-off valve for all four teats. This means two of the four could be milked completely dry and could be feeling high vacuum levels while the other two are still producing milk.

In a conventional milking system, three teats are affected by the milking of the fourth teat.

For example, if operators plug an inflation in a conventional cluster because we are only milking a cow with three teats, the pulsation would be different in the three operating cups than what the cow would feel if all four cups were attached.

A robot allows consistency in pulsation, no matter how many cups are attached. Again, consistency is the key when it comes to milking cows.

So how do robot farms make these individual adjustments, and what should they be watching for?

There are many ways to observe problems when looking at the information generated by a robot. There is a dashboard with various key performance indicators (KPIs).

Some of these KPIs include box time, total milk produced, average milk per cow, failures, treatment time and milk speed. Any large change in these KPIs can indicate to operators there could be a problem.

On our dashboard, there is a seven-day average of the KPIs, as well as a previous 24-hour average. This provides operators a good comparison or basis for making decisions. These KPIs also use red, yellow and green gauges to let operators know if they need to be worried.

The software also provides warnings, such as dead milk time on a certain quarter of a certain robot. This is a good indicator there may be issues with a channel of a pulsator.

The ability to customize pulsator and vacuum settings in automated milking equipment provides an opportunity to be precise and consistent with every milking and every cow.

It can be more comfortable for a cow with a calmer milking experience.  end mark

PHOTO: With pulsation and vacuum components attached to each inflation, some automated milking systems can better customize the milking experience for individual cows. Photo by Karen Lee.

Kaden Schvaneveldt is an Aftermarket Field Specialist – West for Lely North America. Email Kaden Schvaneveldt.