Hazards of incomplete milking

Farmer milking cows
Farm and Dairy file photo.

Technology continues to evolve on the farm, but after many years of using automatic take-offs, human error, cows kicks and machine malfunction continue to cause incomplete milkings.

Some computerized milking systems provide an incomplete milking report. If your system does not provide a complete milking report, there are ways to monitor if your cows are being over- or under-milked.

Incomplete milking

Many studies consider an incomplete milking to be 30% or more milk left in an individual quarter. Many assume the effects of one incomplete milking have little impact on cows, especially when they are milked three times per day. A couple of recent studies, though, show that one incomplete milking may have a long tail and a series of incomplete milkings definitely have a long negative tail to milk production.

Swedish study

Some studies show a decrease in milk for five to 14 days after the last incomplete milking. A study out of Sweden comparing quarter milk found that when a quarter was incompletely milked, it gave 2.27 pound less than expected the next milking, compared to production of other quarters. If this was the entire udder that was incompletely milked, the cow would give 9.08 pounds less the next milking than she would have if completely milked. This decreased milk production continues for almost two weeks after just one incomplete milking, averaging two pounds less per day for the entire udder.

This study also found an increase in somatic cell with just one incomplete milking. This same study looked at the effect of three incomplete milkings one day apart. The effects of each incomplete milking was very similar, with the next milking seeing a little over two pounds less per quarter, and the reduced milk lasting a little over a week.

Wisconsin study

While the study in Sweden was on a two-times-a-day milking schedule, another study from Wisconsin studied the effects of incomplete milking in a two- versus a three-times-a-day milking schedule. The theory many have is that when cows are milked three times per day, incomplete milkings have less effect. Unfortunately, this was not found to be true. Both milking frequencies saw almost a 25% decrease in milk production and an increase in somatic cell.

Why do we see the same decrease in milk production with either milking frequency? We know very well that each quart produces milk independent of the others. When 30% of the milk is left in the quarter, it fills with milk quickly and a signal is created that decreases milk production. Once the cistern is full, the aveolar compartment exceeds capacity quickly and signals a decrease in milk secretion rate.


Knowing that incomplete milkings harm production long-term, how can we help prevent these problems?

The first priority needs to be keeping machines well-maintained and testing automatic take-off settings occasionally to be sure they are not under- or over-milking cows. One way of checking settings is to check the amount of time at low flow when it drops below 1.4 pounds per minute until the flow stops. This is one way of checking if someone is putting units on manual or if a detach setting is out of calibration.

If you have an incomplete milking report, checking that report after each milking can help you determine which units may need some maintenance. Maintaining these units as soon as a problem arises not only maintains production but also saves many employee headaches.


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