There are six primary goals to achieve when considering the layout of a barn:
- Easy movement of cows between groups and within the group
- Easy movement of cows to and from the parlor with minimal disturbance to neighboring groups while minimizing the distance traveled
- Easy access for feed delivery
- Easy access to feed and water by the animals
- Easy expansion of the facility
- Convenient manure removal
To achieve the first two goals, most barns are designed so pens empty in the middle of the barn with a cross alley providing access to the milking center. Pens are usually laid out for drive through feeding via a 20-foot (6.1 m) wide central alley. Alternatively, drive-by feeding may be used along an exterior wall. This approach is often used in conjunction with automated milking systems as it facilitates robot location and access.
The barns may be located either perpendicular to (T-style) or parallel to (H-style) the milking center.
In H-style facilities, space is available behind the parlor holding area for the special needs barn, the orientation of all buildings facilitates natural ventilation, cow flow from one barn does not interfere with operations in other barns, and walking distance to and from the milking center is minimized as the herd expands. Expansion of the facility occurs by adding barns parallel to the existing ones on either side of the parlor.
In T-style barns, the manure from the holding area can easily be incorporated into the existing handling system of the attached freestall barn, and only a single connector alley is required. Expansion must occur with more barns farther from the parlor, parallel to the existing barn. The special needs facilities in T-style barns are usually located perpendicular to the parlor on a separate limb off of the holding area. Care must be taken to design the size of the holding area large enough to accommodate larger milking group sizes in the future since it is difficult to expand the holding area with this arrangement.
T-style barn layout with expansion of barn 2 away from the milking center and the special needs facility linked to the holding area
H-style layout with expansion of barns 2, 3 and 4 on either side of the milking facility, and the special needs facility linked to the holding area between the lactating cow barns
Barns may be built where the pens empty at one end. However, in this layout, the option to divide pens is limited and results in groups of cows being moved through pens closest to the milking center. Alternatively, a transfer lane (drover’s alley) can be built on the outside wall of the pen to facilitate movement. These are very useful in special needs barns that usually have several small groups of cows. These lanes are at least 8 feet (2.4 m) wide or wider dependent on the number of cows in each group.
A transfer lane in a special needs barn to facilitate cow movement
Being able to easily move cows around in a special needs barn is very important. For that reason, a gate triangle is recommended to single handedly trap a cow and move her to the transfer lane. The arrangement is shown below.
A gate triangle in operation in a 2-row tail-to-tail pen. The triangle utilizes the space taken by two stalls. The gate is opened to close off the cross alley and the cow is brought into the triangle. Once captured, the cow may be examined in a headlock or moved elsewhere along a transfer lane.
