Comparison Factors Farmers Should Check
Choosing between a herringbone milking parlor and a parallel parlor is more than a building design decision—it directly shapes daily milking routines, cow flow, labor efficiency, and long-term herd management. Both parlors are widely used on dairy farms, but they position cows differently, change how operators work, and affect throughput in distinct ways.
This guide compares herringbone and parallel milking parlors across key practical factors: layout, space, cow movement, labor ergonomics, cleaning, and capacity. Whether you are planning a new parlor or upgrading an existing setup, the comparison helps match parlor design to the farm’s actual task, herd size, and operator comfort—not just the equipment.
What Is a Herringbone Milking Parlor?
A herringbone milking parlor arranges cows at an angle (usually 30° to 45°) along both sides of a central pit. Each cow stands diagonally, with her rear udder accessible from the pit. The operator works from a lowered walkway, attaching and detaching milking units from the side of the animal. This layout provides good visual inspection of the udder and makes teat spraying and dipping straightforward.
Cows enter and exit individually through sequential gates or swing gates. The typical cycle is: cows wait in a holding area, move into the parlor one by one or in small groups, take their angled position, are milked, and then exit forward or backward depending on the setup. Common herringbone configurations include double‑4, double‑6, double‑8, and larger numbered doubles (each number indicating stalls per side). According to the Dairy Cattle Science handbook (4th Edition, Chapter 14, p. 423), herringbone parlors have been a mainstay on medium‑sized dairies due to their efficient use of pit length and clear visibility of the udder from the working pit.
What Is a Parallel Milking Parlor?
In a parallel milking parlor, cows stand side‑by‑side perpendicular to the operator pit, with their rear ends facing the pit. The milker attaches units from between the cow’s rear legs, working at a lower height compared to herringbone designs. Cows are typically batched—all cows on one side enter simultaneously, are milked, and exit forward as a group, enabling rapid turnover.
This layout maximizes cow density per linear foot of pit and reduces the distance operators must walk. Parallel parlors often suit larger herds where high throughput and quick group entry/exit are priorities. The Dairyland Initiative, an outreach program of the University of Wisconsin–Madison School of Veterinary Medicine, notes that parallel parlors can reduce individual stall time because cows enter and leave as a group, which helps maintain a steady milking rhythm in large dairies.
Herringbone vs Parallel: Layout and Space Comparison
Space efficiency, building width, and operator work zones differ noticeably between these two parlor types. The table below summarizes the key layout parameters to help compare them on your farm’s footprint.
| Comparison Factor | Herringbone Milking Parlor | Parallel Milking Parlor |
|---|---|---|
| Cow positioning | Angled (30°–45°) to pit | Perpendicular (rear to pit) |
| Space per stall | Wider individual stall width needed due to angle | Narrower stall width, more cows per pit length |
| Pit length for same number of stalls | Longer pit required | Shorter pit possible |
| Building width | Often narrower overall building | Wider building needed for cow platform depth |
| Operator work area | Clear side access to udder; pit typically 2.5–3.0 feet deep | Front‑on access between rear legs; pit depth similar |
| Cow entry/exit style | Sequential or small‑group; more individual movement | Whole‑side batch entry and rapid forward exit |
| Best fit (typical) | Medium herds, dairies wanting side‑udder access, retrofit barns | Large herds, high‑throughput operations, new construction |
General recommendations from University of Kentucky Cooperative Extension emphasize that parlor selection must start with stall dimensions that match cow size, not simply a preference for one layout over another. In both designs, stall length, width, and platform slope directly impact cow comfort and milking efficiency.
Cow Flow and Animal Handling Differences
Cow flow—the way animals move into, through, and out of the parlor—is a critical difference between herringbone and parallel designs. In a herringbone parlor, cows are typically loaded one or two at a time and must turn or pivot to fit into the angled stall. This individual handling can be calmer, reducing competition at entry, but it also means the entire group does not move simultaneously, which can lengthen the total parlor cycle if not managed well.
Parallel parlors promote rapid, group‑based movement. All cows on one side enter at once from a backing gate or crowd gate, take their positions in tight side‑by‑side stalls, and exit simultaneously. This reduces idle time and keeps the milking routine consistent. However, because cows face forward and are released as a group, the system depends on cows being trained to enter and stand squarely; otherwise, backing up or shuffling can delay the cycle.
For herds with aggressive or shy cows, the angled spacing of a herringbone can reduce stress by giving each cow a more defined individual zone. In contrast, parallel parlors pack cows closer together, which some dairy researchers note may increase displacement behavior in lower‑ranking animals (Beef and Dairy Cattle Welfare, Chapter 7, p. 182).
Labor Efficiency and Operator Comfort
Operator comfort and task repetition influence labor efficiency and worker retention. In a herringbone parlor, the milker works from the side of the udder, allowing a natural arm movement for attaching teat cups and applying post‑dip. Many operators find this side‑access position easier on the back and shoulders over long milking shifts. Visual inspection of the udder and teats is direct, and hock‑to‑udder orientation with minimal bending is often cited as an ergonomic advantage.
In a parallel parlor, the milker must work between the cow’s rear legs, attaching units from behind. This front‑on approach can require more stooping or a deep lunge if the platform height and pit depth are not perfectly matched to the operator’s stature. However, because cows are closer together, the walking distance per milking is reduced, which can lower fatigue in large parlors. Many modern parallel installations include adjustable floor platforms or rapid‑exit front gates to further streamline work routines.
The Dairy Production Medicine handbook (Chapter 11, p. 310) notes that parlor pit floor height relative to the cow platform is one of the most overlooked ergonomic factors, regardless of parlor type. A poorly configured pit can cause repetitive strain injuries in both herringbone and parallel operations.
Cleaning and Maintenance Considerations
Both parlor designs require daily cleaning and periodic deep sanitation, but the waste management approach differs. Herringbone parlors typically slope the cow platform slightly toward the pit, allowing urine and manure to flow into a flush or scraping system in the pit. The diagonal stall arrangement can leave small corners where bedding or manure accumulates, requiring manual attention between milking shifts.
Parallel parlors often feature a flat or gently sloped platform, with alley scrapers or flush systems running under the cow stalls. Because cows stand perpendicular, waste drops straight down into a catchment gutter behind the cow curb. This can simplify automatic cleaning, but the narrower passages between rows may be harder to access with larger cleaning tools. Regardless of design, thorough daily washing of the parlor pit, stall surfaces, and milk hose attachments remains essential—consistent with guidelines from the USDA Dairy Animal Care Quality Assurance program.
A simple cleaning checklist to compare:
- Herringbone: Watch for buildup in corners behind each stall; flush feed alleys after each group; ensure udder spray lines do not become clogged with bedding.
- Parallel: Inspect the rear curb drain for blockages; check that rapid‑exit areas stay free of slurry buildup; verify alley scrapers are adjusted to the narrower platform width.
Capacity and Throughput
Throughput—cows milked per hour—is a major driver when choosing between herringbone and parallel parlors. Herringbone parlors tend to have a slightly slower individual stall time because cows enter sequentially, but they can achieve steady throughput when stall numbers match the herd size and milkers work efficiently. A double‑8 herringbone, for example, might handle 60–80 cows per hour under good management, while a double‑12 parallel could comfortably reach 100–120 cows per hour due to group entry and exit.
Parallel parlors are frequently chosen for herds exceeding 500 lactating cows because the layout supports quick, batch milking with fewer operator steps. However, the total parlor time depends on milk-out duration, not just entry speed. If cows produce high yields and require long attachment times, the advantage of rapid entry is partially offset. Herringbone designs can be a better fit when milking speed variability is high across cows, as the individual stall allows slower milkers to finish without blocking the whole side.
University of Wisconsin Extension suggests that for herds under 300 cows, a double‑6 or double‑8 herringbone often provides sufficient capacity without the higher infrastructure cost of a parallel installation. For very large dairies, parallel or rotary parlors become more common.
Which Parlor Fits Your Dairy Task?
There is no single “best” parlor—only the one that aligns with your herd, labor, and management goals. Use this decision checklist to narrow your choice:
- Herd size and growth plan: If you milk fewer than 300 cows and don’t expect to double soon, a herringbone often fits. For expanding dairies over 500 cows, parallel may future‑proof your investment.
- Operator preference and availability: If your team favors side‑udder access and clear visual inspection, herringbone can boost morale. If minimizing walking distance is priority, parallel may help.
- Existing barn footprint: Retrofitting a narrow barn usually suits herringbone; new construction on a wider site can accommodate a parallel’s platform depth.
- Cow handling style: Farms with calm cows that train easily to batch entry often succeed with parallel. Herds with nervous individuals may benefit from the angled individual zone of a herringbone.
- Cleaning resources: If automatic alley scrapers and flush systems are already in use, parallel can integrate well. Herringbone corners may need more manual labor if automation is limited.
- Milking routine variability: When cows have very different milking times (e.g., multi‑breed herds), herringbone gives individual release without delaying the whole group.
These factors are guidance, not hard rules. Visiting working farms with both designs and talking to operators about their daily experience provides the most realistic perspective.
Common Mistakes When Choosing a Parlor Type
Avoid these frequent missteps that can turn a parlor investment into a daily frustration:
- Focusing only on purchase price: Labor, cleaning time, and cow flow bottlenecks have long‑term costs that outweigh initial savings.
- Ignoring current cow size: Stall dimensions must fit your largest cows—not industry averages—to prevent udder injuries and refusal to enter.
- Underestimating peak milk time: A parlor that works at average throughput may fail during the busiest milking shift, causing heat stress and holding area crowding.
- Mismatching group size to parlor side length: If your pen size is 40 cows but your parallel side holds 24, you’ll need to split groups and lose efficiency.
- Neglecting pit floor ergonomics: The best parlor layout fails if the operator work level causes back strain. Pit depth and platform height must be paired to the milking team’s stature.
- Forgetting expansion needs: Planning for future growth without overbuilding the initial parlor requires a practical balance—an under‑sized parlor becomes a major constraint.
- Assuming automatic cleaning solves everything: No flush system replaces a manager inspecting tailhead cleanliness and parlor hygiene between shifts.
Input from independent dairy engineers and extension educators, such as those at Penn State Extension Dairy Team, repeatedly shows that parlor design failures often trace back to overlooking these on‑farm details during the planning phase.
Frequently Asked Questions
Initial construction costs vary more by stall number and materials than by type alone, but herringbone parlors often require a longer pit and may fit into existing narrower buildings, which can reduce site‑prep costs. Parallel parlors typically need a wider building span, which might increase structural cost; however, the shorter pit length can offset some expense.
A full conversion is rarely practical because the pit location, stall curbs, and entry/exit gates are built around the angled layout. Retrofitting to parallel usually means major demolition. Some farms add rapid‑exit features to a herringbone to improve throughput, which is a simpler update.
A double‑8 herringbone (16 stalls) is a common choice for herds milking 100–200 cows in a 2‑hour session, assuming three milkings per day. It can handle more if cows have consistent fast milk‑out times, but group sizes should match the 8‑per‑side batch to avoid idle stalls.
Both designs can be safe when properly installed. Parallel parlors keep cows close together, which can reduce the risk of a milker being kicked from the side, but the front‑on attachment from the rear can put the operator closer to a possible kick. Proper restraint bars, cow‑training protocols, and non‑slip floors are essential regardless of design.
In cold climates, a herringbone pit may be easier to insulate and keep warm because the building footprint is narrower. In hot weather, the wider platform of a parallel parlor allows more ventilation across cows. Both designs can work in any climate with the right curtain and fan placement.
Failing to inspect and replace rubberwear—liners, hoses, gaskets—on schedule is the top cause of premature parlour system failures. Beyond that, letting manure pack around gate hinges and crowd gate tracks leads to cow flow delays that cost more time than most cleaning shortcuts save.
It is critical. In parallel parlors, cows must learn to stand square and exit forward without hesitating. In herringbone designs, training focuses on getting the animal to turn and position correctly in the stall. A rushed introduction without a quiet acclimation period often results in broken equipment, injured cows, and frustrated workers.
Yes, but stall dimensions must accommodate the largest breed. Holsteins need deeper and wider stalls than Jerseys. Herringbone stalls can be slightly more forgiving for size variation because the angled entry provides a little extra lateral space, but adjustable neck rails and rump rails are beneficial in both types.
References
- Penn State Extension guide to Standard Operating Procedure for the Milking Facility
- Penn State Extension guide to Safety Risks in the Milking Parlor Non Biological Exposures
- Penn State Extension guide to Seconds Do Matter in Your Milking Routine
- Penn State Extension guide to Transitioning to a New Robotic Milker
Related Guides in This Category
- Milking Parlour: Practical Farm Use, Selection and Daily Management Basics
- Rotary Milking Parlor vs Parallel Parlor: Which System Fits Large Herds?
- Parallel vs Herringbone vs Rotary vs Tandem: Which Works Better for Your Farm?
- Types of Milking Parlour: Practical Options for Livestock Farms
- What Is Milking Parlor and When Does It Make Sense on a Farm?
- Milking Parlour Design Placement for Better Livestock Access and Daily Workflow
- Small Milking Parlour Design Placement for Better Livestock Access and Daily Workflow
- What Is a Milking Parlour and When Does It Make Sense on a Farm?