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Timing the milking procedure

Quick facts

Timing is one of the most important factors of a successful milking procedure.

  • 10-20 seconds of stimulation for milk letdown.
  • 30 seconds of contact time with teat dip.
  • 60-120 seconds of prep-lag time.
  • 30 minutes of keeping cows standing after milking.

Harvesting milk is the final step in the milk production process on the farm. Whether milking cows in a parlor, a tie stall, or another setup, proper milking procedure is critical to ensure food safety, milk quality and cow health.

Proper milking procedure is all in the timing.

Stimulation of milk letdown (10 to 20 seconds)

This is the amount of stimulation time the teat skin surface requires for optimal milk letdown. This can include wiping the teats and cleaning them of any dirt and manure.

The most powerful milk letdown stimulus is fore stripping each teat. This allows you to check for any visual symptoms of mastitis such as milk with flakes, clots or an off-color.

If a cow has not let down her milk, the extra machine pulsation can lead to damaged teats and teat ends. This negatively affects udder health and can lead to a higher incidence of mastitis.  

Contact with teat dip (30 seconds)

  • 30 seconds is the ideal amount of contact time. It is the time required for teat dip to kill bacteria on the teat surfaces.
  • Dirt, manure and bedding should be cleaned off of each teat before dipping to ensure full skin contact.
  • The key to effective use of teat dipping for mastitis control is consistent and complete teat coverage at every milking.
  • When hastily preparing cows for milking, it can be easy to miss a teat or have incomplete coverage. 

An easy way to test yourself (or your employees) is by using the White Towel Test. It is a great option because it offers immediate feedback and can be used for pre- and post-dipping.

  • To do the test, wrap a clean paper towel around the base of the teat immediately after it has been dipped.
  • Be sure to blot the dip from the entire teat.
  • Unwrap the towel and open it to display the teat dip pattern.
  • A completely and correctly dipped teat will give a full, singular blot on the paper towel.
  • A broken or uneven blot is representative of an improperly dipped teat. 

Prep lag time (60 to 120 seconds)

One to two minutes represents the goal time frame for prep lag time. This is the time from the initial contact with the teat surfaces until the milking machine is applied.

  • The prep-lag time for cows being milked two times per day should be shorter than cows being milked 3 times per day.
  • In a typical parlor setting, prepping four cows at a time will accomplish proper prep lag time for each cow, given there is consistency in stimulation and contact time.
  • For stall barn application, the use of an end-of-milking indicator is helpful in organizing the milking routine.

Time after milking for teat muscle closure (30 minutes)

This may be one of the most important times to remember. After milking, the teat sphincter muscle takes 30 minutes to close. It also takes 30 minutes for the post-dip to dry.

If a cow lies down while the sphincter is still relaxed or before the teat dip has dried, it can lead to bacteria entering the teat and potential infection.

It is estimated that 50 percent of new contagious mastitis infections can be prevented by complete and consistent post-milking teat dipping and allowing the dip to dry.

A good way to keep cows standing for at least 30 minutes after milking to provide fresh feed (or push feed up) so the cows are motivated to stand and eat after milking.

Emily Krekelberg, Extension educator

Reviewed in 2020

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