Source: The Dairyland Initiative
The holding area is a critical component of a dairy farm’s layout. Cows typically spend 60 to 90 minutes per milking in these areas where risk for heat stress and injury can easily be exacerbated.
In this section, we will consider:
- Sizing the holding area
- Floor type and slope
- Parlor entry
- Return lanes
- Transfer lane design
Sizing the Holding Area
The holding area should be sized to accommodate the largest group of cows that will be milked, keeping in mind potential future herd expansions. The size of the holding area size is one of the critical constraints for herd expansion.
The target area per cow in the holding area is 20 square feet (1.9 sq m). An increase of 125% in total area is recommended when the following milking group must be brought in while the prior group is still being milked.
Greater space in the holding area has two major benefits:
- More space allows greater airflow and reduces the risk for heat stress during the summer.
- More space allows cows that wish to enter the parlor first and lead the group into the milking stalls to work their way through the group once the crowd gate has been lowered. These leader cows are often not the same cows that lead the group from the pen to the holding area!
Parlor and pen sizes should be balanced so that cows spend no more than 3 hours per day away from the pen milking, or 60 minutes per milking away from feed and resting areas. In our 2012 survey of Wisconsin dairy farms, the average time away from the pen was 90 minutes, suggesting that we are missing the target substantially as an industry.
Be sure to read our Group Size page for more details on sizing pens and parlors.
Flooring Type and Slope
The floor should be sloped upwards toward the parlor to encourage cows to stand facing the entrance, but should not exceed a slope of 2% to avoid undue stress on cows’ rear feet. Too steep of an incline in the return alleys may cause slipping and stopping as well as excessive claw wear.
Concrete floors should have parallel grooves running lengthwise through the holding area, 0.75-inch wide, 0.5-inch deep and spaced 3.25 inches on center to optimize traction (2 cm wide, 1.3 cm deep, and spaced 8.3 cm on center). Since the very last of the cows in the pen will be standing on this surface for a prolonged period of time, many of which will be the most severely lame cows in the pen, rubber flooring is an excellent option for providing more cushion and traction in the holding area. Rubber with greater compressibility is ideal for the holding area. More information about concrete and rubber flooring can be found on our flooring page.
Holding Area Check List
- Provide 20 sq feet (1.9 sq m) per cow for 125% of the largest group size
- Maximum 2% floor slope with parallel grooves or rubber flooring
Parlor Entry
Crowd gates are important for keeping cows close to the parlor entrance, but do nothing to guide cows to enter the parlor smoothly. Misuse of the crowd gate to force cows to enter the parlor is routine and a major welfare concern. Injuries are commonplace and easily preventable. We recommend putting a time limit on the crowd gate button so the milkers may only move the gate for a short fixed time to prevent its misuse. Milking machine manufacturers are now using ear tag RFIDs to drive motors to move the crowd gate based on entry of cows into the parlor area. This has the enormous benefit of taking the crowd gate use out of the hands of the milkers.
Proper guidance at the front of the holding area must be in place to encourage cows to move quickly and in a single file into the parlor. The front of the holding area should narrow to a 3.5-foot (1.1 m) wide entry lane so that only one cow can enter the parlor at a time. The entry lane must be sufficiently long for two cows to stand nose-to-tail, waiting to enter the parlor in single file, follow-the-leader fashion. We suggest an entry lane of 12 feet (3.7 m) long. The holding area must narrow to the entry lane in order to bring the next cow up while avoiding pockets where cows may become trapped or wide funnels in which cows may stand across and block entry. Failure to channel cows toward the parlor entrance will result in frustrated milkers needing to leave the parlor to fetch cows, and subsequently inefficient parlor throughput.
Return Lanes from the Parlor
Single file return lanes from each exit of a double-sided parlor must be 4 feet (1.2 m) wide to accommodate one cow-width. For rotary parlors with a single exit point and a cow exiting every 6.5 seconds, the return lane should accommodate at least two cow-widths, or be at least 8 to 10 feet (2.4 to 3 m) wide. If the lane will be scraped by a skid loader or tractor, be sure to account for the machinery width as well.
Cows should not need to wait in the return lane, but should have free movement back to the pen as soon as possible to reduce the time spent away from the pen and improve the throughput efficiency of the parlor. Where dual transfer lanes are not feasible, the return lane may need to provide 15 square feet (1.4 sq m) per cow for the number of parlor turns estimated to be completed before the finished group can be let back to its pen.
Dual return lanes should be provided to allow cows to bypass the footbath on days when it is not in use, thus preventing cows from filling the bath with manure and potentially spreading infectious causes of lameness through the herd. Read more about designing effective footbaths in the Wisconsin Blueprint.
Return lanes should not be used as palpation rails, and palpation rails should not be located parallel to the return lane. Requiring cows to stop as they exit will slow the throughput of the parlor and prolong the time cows spend away from their pen and feed. Our recommendations for restraining cows for managerial tasks are a separate work area adjacent to a sort gate, or headlocks at the feedbunk for reasons of safety and efficiency. If palpation rails must be used, they should be located adjacent to a transfer lane between the milking center and barn without causing a bottleneck to moving groups of cows.
Transfer Lanes
Inadequate transfer lane width and accessibility can be a source of frustration on any size farm, particularly on very large dairies where the parlor must run nearly 24 hours per day. Anyone that has worked or watched the movement of cow groups through a large dairy facility knows how this dance between moving groups to and from the parlor can easily be disrupted and contribute to the inefficiency of the milking center. By the time the first group of cows has been fully brought up to the parlor, a few turns of the parlor have already been completed and cows must wait in the exit lanes, prolonging the time cows must spend away from their pen and potentially backing up the release of cows from the parlor. It is no wonder cows are often mixed up between groups, resulting in yet one more chore on the dairy – finding “missing” cows for reproductive work, drying off and other managerial tasks.
Building holding areas large enough to hold the largest group of cows is certainly the starting point to solving this problem, but it is not the entire solution. Dual transfer lanes are particularly useful on large dairies (>1500 cows) that must move groups over long distances and/or have very large groups of cows. With appropriate gate placement, dual transfer lanes will allow one group of cows to move to the holding area while the previous group of cows can freely return from the parlor to their pen.
For herds >1500 cows, the width of each lane of a dual-transfer lane should be a minimum of 15 feet (4.6 m) to allow free, fast, and safe movement of cows as the group is exiting the pen and moving to the parlor.
Dual transfer lane in a cross-ventilated barn allows for simultaneous movement of groups of cows to and from the milking center.
Holding Area Ventilation and Cooling
Milking center holding areas have been identified as one of the highest risk locations for heat stress on modern dairy farms (Collier, 2006, JDS). Modern holding areas are typically ventilated using natural ventilation to move fresh air into the holding area with recirculating fans to create air velocity on the backs of wetted cows. These systems can work well provided that the holding area is well exposed to prevailing winds and that there is an adequate number of recirculating fans.
However, many holding areas are not sufficiently exposed to winds, and although recirculating fans create air velocity on the cows, the air can become increasingly hot and humid as it gets recycled within the space.
Thus, milking center holding areas require special attention for cooling strategies. Cows should cool while thermal panting and standing since they increase their body surface area available for cooling. However, if cows are collected together in a tight space with poor air flow, cooling is compromised. Providing the necessary space and adequately sizing the parlor for efficient cow throughput will help decrease heat stress within the holding area.
To exhaust the warm air from the space, natural and mechanical ventilation options can be considered, but they must be supplemented with the addition of fans over the cows and a soaker system for use in hot climates.
Holding Area Soakers
Soakers should be provided to wet the cow before entering the parlor and be activated at temperatures above 70°F (21°C). Nozzle spacing can be made equal to the spray diameter and placed in a grid pattern to cover the holding area using nozzles with at least 25 gallons (95 liters) per hour rated to deliver 1 gallon per 150 square feet (1 liter per 3.7 square meters) of holding area space within a 1-minute period. Cycles can be 1 minute every 5 minutes or 2 minutes every 10 minutes. If larger nozzles are used, spray patterns should overlap by 10 to 25 percent. Pressure in the distribution line should be 15 to 20 psi (103 to 138 kPa or 1.03 to 1.38 bar), and the water supply should provide 1 gallon (3.8 liters) per 10 cows per cycle. All equipment should be about 9 feet (2.7 m) above the floor.
Soakers in the parlor exit lanes and the parlor itself have been used on some farms, but cannot be relied upon to replace the recommendation for soaking before milking at this time.
Sprinkler nozzle requirements based on holding pen capacity
| Holding Pen Capacity (number of cows) | Typical Holding Pen Size (feet by feet) | Water Required (gallons)* | Minimum Flow Rate (gal per min)** | Number of 360-Degree Nozzles Required*** |
|---|---|---|---|---|
| 40 | 24 by 32 | 20 | 10 | 14 |
| 60 | 24 by 42 | 25 | 12 | 20 |
| 80 | 24 by 50 | 30 | 15 | 27 |
| 100 | 32 by 48 | 40 | 20 | 34 |
| 120 | 32 by 56 | 45 | 23 | 40 |
| 160 | 32 by 75 | 60 | 30 | 54 |
| 200 | 32 by 96 | 80 | 40 | 68 |
| 300 | 32 by 144 | 120 | 60 | 102 |
| 400 | 32 by 192 | 150 | 75 | 136 |
| 500 | 32 by 240 | 200 | 100 | 170 |
| Holding Pen Capacity (number of cows) | Typical Holding Pen Size (meters by meters) | Water Required (liters)* | Minimum Flow Rate (liters per minute)** | Number of 360-Degree Nozzles Required*** |
|---|---|---|---|---|
| 40 | 7.3 by 9.8 | 75.7 | 37.8 | 14 |
| 60 | 7.3 by 12.8 | 94.6 | 45.2 | 20 |
| 80 | 7.3 by 15.2 | 113.6 | 56.8 | 27 |
| 100 | 9.8 by 14.6 | 151.4 | 75.7 | 34 |
| 120 | 9.8 by 17 | 170.3 | 87.1 | 40 |
| 160 | 9.8 by 22.9 | 227.1 | 113.6 | 54 |
| 200 | 9.8 by 29.3 | 302.8 | 151.4 | 68 |
| 300 | 9.8 by 43.9 | 454.2 | 227.1 | 102 |
| 400 | 9.8 by 58.5 | 567.8 | 283.9 | 136 |
| 500 | 9.8 by 73.2 | 757.1 | 378.5 | 170 |
*Assumes application of 0.025 gal of water per cycle per square foot of pen area (0.095 liters of water per cycle per 0.09 square meters of pen area)
**Flow rate based on a 2-minute on cycle with 10 minutes off
***Assumes nozzles have an 8-foot (2.4 m) spray diameter and 0.5 gpm capacity
‘Reducing Heat Stress in the Holding Pens.’ JP Harner III, JF Smith, MJ Brouk, and JP Murphy, Kansas State University.
Circulation Fans
Currently, we rely upon the use of circulation fans to recycle air at high speeds over the cows in the holding area. Cooling air speed recommendations most commonly used suggest 1,000 cubic feet per minute (CFM) (1,699 m3/h) per cow through recirculation fans activated at 65 °F (18 °C). This equates to 10 cows per 36-inch (91 cm) fan and 20 cows per 48-inch (122 cm) fan.
Traditional fan installation for holding area cooling
Traditional fan recommendations based on holding pen capacity from ‘Reducing Heat Stress in the Holding Pens.’ JP Harner III, JF Smith, MJ Brouk, and JP Murphy, Kansas State University.
| Holding Pen Capacity (cows) | Typical Holding Pen Size
(feet by feet) |
Total Fan Capacity Required (cfm) | Number of
30- to 36-inch Fans |
Number of
48-inch Fans |
|---|---|---|---|---|
| 40 | 24 by 32 | 40,000 | 4 | Not Recommended |
| 60 | 24 by 42 | 60,000 | 6 | Not Recommended |
| 80 | 24 by 50 | 80,000 | 8 | Not Recommended |
| 100 | 32 by 48 | 100,000 | 10 | Not Recommended |
| 120 | 32 by 56 | 120,000 | 12 | Not Recommended |
| 160 | 32 by 75 | 160,000 | 16 | 8 |
| 200 | 32 by 96 | 200,000 | 20 | 10 |
| 300 | 32 by 144 | 300,000 | 30 | 15 |
| 400 | 32 by 192 | 400,000 | 40 | 20 |
| 500 | 32 by 240 | 500,000 | 50 | 25 |
| Holding Pen Capacity (number of cows) |
Typical Holding Pen Size (meters by meters) |
Total Fan Capacity Required (m3/h) | Number of 0.76 to 0.9 meter Fans | Number of 1.2 meter Fans |
|---|---|---|---|---|
| 40 | 7.3 by 9.8 | 18,878 | 4 | Not Recommended |
| 60 | 7.3 by 12.8 | 28,317 | 6 | Not Recommended |
| 80 | 7.3 by 15.2 | 37,756 | 8 | Not Recommended |
| 100 | 9.8 by 14.6 | 47,195 | 10 | Not Recommended |
| 120 | 9.8 by 17 | 56,634 | 12 | Not Recommended |
| 160 | 9.8 by 22.9 | 75,512 | 16 | 8 |
| 200 | 9.8 by 29.3 | 94,389 | 20 | 10 |
| 300 | 9.8 by 43.9 | 141,584 | 30 | 15 |
| 400 | 9.8 by 58.5 | 188,779 | 40 | 20 |
| 500 | 9.8 by 73.2 | 235,974 | 50 | 25 |
Larger diameter fans can be more energy efficient than several smaller fans. However, operational cost and efficiency varies across brands (8.3 to 18.6 CFM (14.1 to 31.6 m3/h) per watt). Poor maintenance can reduce fan efficiency by 30 to 50%. Each cooling season, the fan blades and grills should be cleaned, oil applied (if required), and any damages repaired. The fan alignment and orientation should be checked, belts tightened, and thermostat cleaned and calibrated as well.
The throw distance to air speeds less than 400 ft/min (2 m/s) is typically less than 15 to 20 feet (4.6 to 6.1 m) for most fans, so correct positioning is essential to effectively cool all of the cows waiting in the holding area.
Air movement vs. distance from the fan in a holding area with recirculation fans installed along a sidewall
Air movement vs. distance from the fan in a holding area with recirculation fans installed over the length of the holding area
Horizontally-positioned, 50- and 72-inch (127 and 183 cm) cyclone fans have recently been marketed, which improve throw distance and produce extremely large volumes of air movement.
