Alleyway Dimensions

In each pen, there are two to three types of alleys. A feed and stall alley runs adjacent to the feed bunk and also has access to stalls (three-row and two-row head-to-head and head-to-tail pens). A feed alley provides access only to the feed bunk (two-row tail-to-tail pen) and a stall alley provides access to stalls along either side. Alley width recommendations vary depending on their purpose and are shown below:

Alley width recommendations by alley type

For the feed alley, where a cow must stand at the bunk eating, we suggest that there be sufficient space for two cows to pass behind the cow side-by-side. If cows are approximately 3 feet wide (0.9 m) and 6 feet (1.8 m) from brisket to tail, then the standard alley width is 6 + 3*2 = 12 feet (3.7 m). For a feed alley with stall access (head-to-head or head-to-tail layout), we add 1 to 3 additional feet (0.3 to 0.9 m), and for a stall alley, with no feed or water access, a standard of 10 feet (3.1 m) is recommended. The width of the center alley in drive through feed barns with bunks on either side of the alley are determined by the width of the feed delivery equipment, but usually range between 18 and 20 feet (5.5 m to 6.1 m).

Recommended alley and crossover widths for 2- and 3-row pen layouts

Crossovers between the feed and stall alleys must be located at the ends of each pen. Waterers are usually positioned at these locations and it is preferable to place them along the outside wall rather than up against the stalls to facilitate cow movement and to keep water from entering the stalls. In cold climates however, they may have to be installed adjacent to the stalls to prevent freezing. If we are to provide for free movement of cows while cows drink at these locations, then the alley must provide a minimum of 12 feet (3.7 m) of available space for a cow to drink and two cows to pass behind her. As most water troughs are usually 2 feet (0.6 m) wide, the total alley width should be at least 14 feet (4.3 m). Where a waterer is shared between two pens, the crossover in each pen should be 13 feet (4 m), or a total of 26 feet (8 m) around the shared waterer. Crossovers without waterers may be 8 to 10 feet wide (2.4 to 3.1 m). The crossover is usually elevated above the feed and stall alleys, and should not be excessively crowned as these areas can become very slippery. Usually a 0.25- to 0.5-inch (0.6 to 1 cm) rise to the center is sufficient. Crossovers adjacent to the manure discharge end of the alley may be raised 4 inches (10 cm) above the feed and stall alleys, and those farthest away may be at the same level or raised just 2 inches (5 cm). In flush barns, or very long pens, cross overs may need to be elevated more to reduce the spillage of manure into the area.

The issue of how great a distance a cow should have to walk between crossovers between the feed alley and the stall alley is open for debate. One can argue that the distance should be less in pen layouts with no direct stall access from the feed alley (i.e. tail-to-tail layouts), but distances of 80 to 100 feet (24.4 to 30.5 m) or 20 to 25 stall widths are currently suggested in most lactating cow pens. We would recommend every 20 stalls for tail-to-tail layouts and 25 stalls for other stall layouts. In transition cow pens, more frequent crossovers every 12 to 15 stall widths (about 60 feet or 18.3 m) are recommended to improve bunk availability.

Waterers are usually located in crossovers, and water access must be taken into account when determining the optimum number of crossovers. The current recommendation is to provide at least 3.5 inches (9 cm) of accessible water trough perimeter per cow with water access spread out between at least two locations in the pen. Head-to-head platforms will support larger waterers 10 to 14 feet (3.1 to 4.3 m) long, while tail-to-tail layouts are restricted to waterers less than about 8 feet (2.4 m) long.

Whatever the width, the alleys should be sloped along their length to facilitate drainage. The degree of slope depends on the length of the alley, the system used for manure removal (e.g. flushing compared with scraping), and the type of bedding. Typical slopes along the length of the alley vary from 0.5 to 2%. We recommend 1 to 1.5% slopes for manually scraped alleys and 2% for flush alleys.

Floors may also be sloped across the alley. With the dry floor concept, the alleys are sloped from the edges into the center about 0.5 to 0.75 inches (1 to 2 cm). The liquid may be collected in a sunken transfer pipe installed below the level of the floor, which is scraped by a paddle connected to V-shaped scraper blades, which move the dried manure along the alley floor.

A concrete floor above a sunken liquid transfer pipe. The floor is gently sloped to the center so liquid is removed from the floor and the scraper moves only dry manure along the length of the alley while the liquid is transported through the pipe (Courtesy of Charles Guard)

The floor has a gentle slope to the center with an 18-inch (46 cm) diameter pipe located below the slot opening	Most of the wet slurry is moved within the pipe by a separate scraper while the scraper above the floor moves a small amount of dry manure

Flush alleys are usually sloped 0.75 of an inch (2 cm) from the feed side to the stall side of the alley so that a greater volume of flush water passes by the freestall curb, facilitating movement of cow manure from this location.