Herringbone parlors are the most common parlor type in the US for ‘small’ parlors (less that double 12). Cows stand on an elevated platform in an angled or herringbone fashion facing away from the operator area. This exposes enough of the back half of the cow to allow access to milk her from the side and room for an arm type detacher and associated equipment.
Herringbone parlors are located on the end of a rectangular holding area allowing cows to enter single file as a group directly into either side of the parlor. On completion of milking the cows exit single file by walking straight ahead and out of the parlor. In most layouts the cows make either a 180-degree turn down a return lane back past the holding area or a 90-degree turn and out a side door or across the parlor to a return lane on the other side. Parlors with more than 12 stalls on a side benefit from rapid exit stalls to speed up the exiting process. In this case the cows walk straight away from the operator area in to a wide exit area. Normal design has a return lane on either side so cows go directly from the exit area past the holding area. However, cows on one side can be directed across to a single return lane on the other side.
As the number of stalls on a side increases it becomes more difficult to keep track of each cow and milking machine. In larger parlors the two rows of stalls may be arranged in a wedge or “V” configuration resulting in a wider operator area on the end away from the parlor animal entrance. This improves the visibility of units and cows from the other side of the operator area.