Stall Layout

Number of Stall Rows

Pens may be designed typically with one, two, three or even four rows of stalls and a single feed bunk. Pens with four rows of stalls are usually designed with feeding along two exterior walls, effectively making them a 2-row pen.

A 2-row pen with a head-to-head stall arrangement

One-row pens are sometimes used, particularly in fresh cow or special needs pens, but in large freestall facilities, 2-row or 3-row pens are most commonly found. Each design has its advantages and disadvantages, which are contrasted in the table below. The greatest difference between the types of pen design is the allocation of feed space per cow. When stocked at one cow per stall, 2-row pens provide approximately 27 to 29 inches (69 to 74 cm) of bunk space per cow, while 3-row pens provide only 16 to 18 inches (41 to 46 cm) of bunk space per cow.

A 2-row pen with a tail-to-tail arrangement

The fact that there are many successful high producing dairy herds housed in barns with 3-row pens suggests superior management may compensate for limited access to feed. Feeding behavior research shows periods of maximal bunk use are related to fresh feed delivery and return to the pen after milking. The delivery of a fresh total mixed ration (TMR) is the strongest stimulus to feeding. Intense bunk activity is typically observed for a period of 60 to 90 minutes. During this time, subordinate cows are unable to access feed unless sufficient space is provided so all of the cows can eat at the same time. Dominant cows eat to satiety, sorting the ration to a degree dependent on its ingredients and processing, while subordinate cows become hungry and gain access to a ration that has been sorted of fine particles. Where feed access is limited, problems may be reduced by ensuring feed is pushed up when cows return to the pen after milking, and by delivering fresh feed more than once a day at times other than at milking time. These adaptations to feeding management reduce the effect of limited feed space at peak feeding times by stimulating feeding activity at multiple times throughout the day. The decision to build a 3-row pen must therefore incorporate different requirements for feed management.

Another difference between 2- and 3-row pen layouts is the effect on barn width, which affects the ability of the barn to naturally ventilate as well as affects the build-up of heat in the barn. A 4-row barn (two, 2-row pens with a central feed alley) with a 12-foot (3.7 m) sidewall height and a 9-foot (2.7 m) effective sidewall opening height will require only about a 1.8 mph (2.9 kph) wind for adequate ventilation, while a 6-row barn (two, 3-row pens with a central feed alley) and similar sidewall construction will require about a 3 mph (4.8 kph) wind for adequate ventilation (Stowell, 2000). With increased stocking rate per square foot of facility, heat units produced by the cows also increase per square foot. Reduced area per cow in 6-row barns results in increased heat load compared to 4-row barns, and in some situations, this may result in a 5 to 8 lb (2.3 to 3.6 kg) milk per cow per day differential between the two types of barns, in favor of 4-row barns.

A comparison of 2-row and 3-row pen designs

Three-row pens are commonplace largely because they appear to be cheaper to build on a per stall basis. However, 2-row pens are often overstocked marginally per stall at up to 15% more cows than stalls because of the greater provision of feed space per cow. Therefore, on a building cost per cow basis, the difference between overstocked 2-row barns and 3-row barns stocked at one cow per stall is substantially reduced. Other advantages of a 2-row design include better ventilation, less heat accumulation, more square feet of alley to reduce manure contamination of the cows’ legs, easier animal handling and monitoring, and better water allocation.

A 3-row pen with a single row of stalls against the sidewall and a row of head-to-head stalls

Pen Layout

There are three options for 2-row pen designs: head-to-head, tail-to-tail, and head-to-tail layouts.

The tail-to-tail layout is preferred by some because of the ease of cow movement through the pen between stall and feed alleys. Stall platforms optimize cow placement with no social obstructions. However, increased traffic between feed and stall alleys creates bottlenecks for feed and resting space access, likely justifying more frequent crossovers with this layout design. Head-to-head and head-to-tail designs improve access to stalls from the feed alley, reducing the problem of accessing a resting space through busy crossovers. Head-to-head pen designs move the stalls away from the sidewall, out of direct sunlight and rain, and share divider mounting posts. The wide stall platform also allows for the installation of longer water troughs in the crossovers.

A 2-row, head-to-tail pen. The specific advantage for this design is for prefresh pens, where workers in the central feed alley can survey all cows easily for signs of parturition.

We do not have to build a facility with only one type of pen design. There may be different requirements for dairy cows at different stages of the lactation cycle. For example, where access to feed is more critical, such as during the transition period and in early lactation, a 2-row pen is more desirable than a 3-row pen. For prefresh pens where just-in-time calving is being practiced, the visibility created by a head-to-tail layout avoids the need for workers to enter the pen every hour. For pens where cows must be moved and handled frequently such as a postfresh monitoring pen, a 2-row tail-to-tail layout may assist management. Similarly, in far-off dry and prefresh groups where manure is scraped from alleys manually with a skid loader, the tail-to-tail design has its merits because of the ease of cow movement. This design also lends itself well to the use of a ‘gate triangle’ for single-handed movement of cows between pens. However, for lactating dairy cows beyond the immediate postfresh monitoring period, a 2-row, head-to-head pen moves cows away from the sidewall and presents some cost savings in divider mountings, but suffers from cow placement issues (see section on stalls). For cows beyond peak yield and for far dry cows, the cost savings of a 3-row pen, provided that feeding management is modified, may be attractive.