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Milking robot layouts: Perpendicular vs. tollgate

Jeff Prashaw for Progressive Dairyman Published on 04 December 2018

Automatic milking robots can essentially be arranged in one of two ways when it comes to entry and exit of cows. One way we call perpendicular and the other is tollgate.

Perpendicular is where cows will enter and exit from the same side or area (see Figure 1). Tollgate entry is where cows will enter from one side or area and exit into another (see Figure 2). This article will explore tollgate, including the advantages and disadvantages when compared to the alternative, in both the free- and guided-flow modes of cow traffic.



Perpendicular milk robot arrangement

In free-flow cow traffic, the waiting area before the robot can also act as a fetch pen. The fetch pen is, of course, where overdue cows are manually driven to pass through the robot. The waiting area enters fetch pen mode when one-way finger gates are “lowered” (if they are not permanently in place), in which case the cow flow is considered modified free flow since cows must enter the robot once they have voluntarily entered the waiting area or fetch pen. This is one benefit of tollgate arrangement of robots in free cow flow.

Sortgate milking robot arrangement

Also, with free flow, sorting of just-milked cows is facilitated in a tollgate arrangement, particularly when there are multiple robots in a single group. This is so because if the robots are arranged in a perpendicular entry and exit style, where cows enter and exit the robot from the same side or area, then each robot will require a sort gate immediately at the exit. Therefore, there will be several sort gates and cows will potentially need to pass through another, adjacent robot if they are tandem, or in-line.

Tollgate sorting of just-milked cows occurs through a single-sort gate into a common separation pen. We will often add a dedicated lane at the sort gate containing a footbath, where cows will only pass through on designated days. In guided traffic, the waiting area before the robot allows only cows that have milk permission into what we call a commitment pen. Thus, only cows that are going to be milked will enter the robot as opposed to free flow, where any cows can enter the robot anytime. Therefore, we eliminate comingling.


The only real drawback of tollgate arrangement of robots is the layout requires more space than perpendicular.  end mark

Jeff Prashaw
  • Jeff Prashaw

  • Project Design Manager – Architect MANA
  • DeLaval Inc.
  • Email Jeff Prashaw