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Factors impacting cow behavior in a robotic milking system

Mat Haan Published on 06 May 2015

dairy cows

While adoption of robotic milking systems on U.S. dairy farms has been slower than in parts of Europe and Canada, these systems are slowly but steadily gaining popularity across the U.S. Greater labor flexibility and decreased labor are often given by dairy farmers as reasons for adopting this technology.



These changes in labor result from the voluntary nature of robotic milking, with the robot milking cows throughout the day and individual cows setting their own milking schedule.

This labor savings is ultimately dependent on cow behavior and whether cows are entering the robot voluntarily as frequently as desired or if the dairy producer is spending time fetching cows for the milking.

A number of factors can influence cow behavior and the number of milkings per cow per day on dairy farms using robotic milking systems; these factors include barn layout, feed and nutrition, management and cow health.

Anecdotally, I have visited robotic milking dairy farms averaging 2.8 to 3 milkings per cow per day I know I need to call in advance because I will not find anyone in the barn, and other farms averaging 2.1 to 2.3 milkings per cow per day I can show up at any time throughout the day and be almost guaranteed to find someone in the barn fetching cows.

Cow time budgets

Whether a cow is milked by a robot or in a parlor, she is going to do the same basic things during the course of the day; these activities include ruminating, resting, standing in stalls or alleyways, eating, drinking and milking. The amount of time a cow spends on each of these activities is influenced by management, health, facility design and other factors.


For cows managed in freestall barns and milked in parlors, researchers in 2010 reported on average cows spending 2.7 hours per day milking, 4.3 hours per day feeding and 11.9 hours per day lying in stalls.On average, lying was broken down into 12.9 lying bouts with an average duration of 1.2 hours per bout.

Researchers in 2013 reported cows managed in freestall barns with robotic milking averaged 10.8 hours per day lying divided among 9.3 bouts per day with an average of 1.3 hours per bout. Based on these two studies, it appears lying behavior of cows milked in parlors and by robots is similar.

Milking time (including time waiting to be milked) may be less with robotic milking. Researchers in 2014 reported cows spent an average of 45 minutes per day milking in four robotic milking dairy farms; these farms averaged 2.2 to 2.7 milkings per cow per day.

While the average across farms was less than the average reported for cows milked in the parlor, there was a large variation between farms in average time milking (13 to 71 minutes), and individual cows spent more than four hours milking or waiting to be milked.

Robot availability and access

With only one cow milked at a time, cows blocking the entrance to or exit from the robot can negatively affect milking efficiency. Blocking occurs when cows congregate in the waiting area either prior to or following milking. It has been observed that primiparous cows are more likely to block the exit from the robotic milker than multiparous cows.

Proper design of robotic milking facilities can prevent some of these blocking events from occurring. Examples of design features include leaving a larger waiting area (20 feet from robot entrance to nearest obstacle) in front of the robot and including longer exit lanes from the robot (long enough for two cows to stand in the lane at a time). If the area in front of the robot is small, locate water sources and cow brushes away from the entrance to the robot so as not to encourage cows to congregate in the area.


Researchers in 2013 reported that older cows and those with a greater number of days in milk less frequently visited the robot and therefore would be cows that would need to be fetched more frequently. A higher stocking density (cows per robot) can also result in fewer milkings per cow. A target of 60 cows per robot is typically recommended.

In the study, dairy farms averaged 55 cows per robot. A survey of robotic milking dairy farms in Pennsylvania found an average of 56 cows per robot with a range of 47 to 64 cows per robot. In general, farms in the Pennsylvania study with fewer cows per robot had greater milkings per cow per day and greater milk production per cow.

Cow motivation

The single biggest factor affecting voluntary milkings is the feed fed at the robot. Typically, cows receive a pelleted feed at the robot; some farms feed ground corn or other grains. Whatever is being fed, it is important that this feed is high-quality, palatable and consistent. The feed should also complement the feed cows are receiving at the feedbunk.

If the feed at the bunk meets all of the nutritional needs of the cow, she will not be as motivated to come to the robot. A partial mixed ration will typically be formulated at a lower energy content than would typically be fed, with the balance of the energy being fed through the robot. PD

Mat Haan is with Penn State Extension. He can be contacted by email. A series of webinar recordings on cow behavior and management in dairy farms using robotic milking can be found on the Penn State Extension website.

References omitted due to spacebut are available upon request. Click here to email an editor.

The feed provided in the robot should complement the feed cows are receiving at the feedbunk. If the feed at the bunk meets all of the nutritional needs of the cow, she will not be as motivated to come to the robot.Photo by Mike Dixon.