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Chapter 9 Milking center options.


After completing the study of this chapter, you should be able to

* measure the milk quality and udder health of a herd.

* identify the advantages and disadvantages of minimal and full milking procedures.

* describe the physical differences between milking center types.

* understand how the structure of each type of center impacts milking procedures, milk quality, animal health, and overall productivity.

* evaluate an existing dairy to determine which type of milking center is most appropriate given the operation's goals, financial position, existing facilities, and operational style.


back-out flat-barn parlor

cluster spacing

coliform count (CC)

contact time

grouping milking routine

laboratory pasteurized count (LPC)

machine on-time

milking center

milking procedure

milking routine

preliminary incubation count (PI)

prep-lag time

prep time

sequential milking routine

somatic cell count (SCC)

standard plate count (SPC)

subway parlor

territorial milking routine

walk-through flat-barn parlor

Cows must be milked, and there are many milking system options to choose from. The best milking center type differs among producers because of their site and situation. The same is true for the different features that are associated with each milking center option. Each of the available features may contribute to labor efficiency, cow comfort, or worker comfort, but the cost of each must be considered and evaluated based on the needs, paybacks, and financial position of the owner. For many producers considering expansion, cows are milked in the barn where they are stabled, whereas other producers already have an independent milking center where cows are taken to be milked. Expanding a herd is often easier for producers who have an existing milking center that can be more fully utilized, since only housing, feed, and manure capacity issues need to be addressed.

Milking Center Types

Milking centers vary greatly across the country. Herd size and climate have a bearing on a producer's choice. Producers with large herds normally select parallel, herringbone, or rotary parlors. Producers with smaller herds, and those making their first move away from milking and stabling their animals in the same barn, often choose lower-cost options. Switch milking, flat-barn parlors, swing parlors, used equipment, and the use of existing barns to house the milking center are common. These smaller operations often select parallel, herringbone, or auto-tandem (side opening) parlor types. With all herd sizes, the milking center choice should be based on the short- and long-term goals of the operator and the expected cost to harvest milk.

Switch Milking

Switch milking refers to using an existing barn and "switching" pens of animals into the facility to be milked. For instance, a producer with an existing 50-stall barn may build a new freestall barn to house cows in pens of 50 animals that can be taken to the old barn and milked. This option has a low capital cost because existing equipment and facilities are used, but the labor cost associated with milking and moving cows is often high. For smaller operations or producers with limited capital, this should be considered if the barn is located within reasonable walking distance of a proper building site that can support the operation's long-term expansion needs. Walking distances of over 500 feet have been used successfully in the past. Cows adapt well to the walk, but proper lighting, snow removal, and other worker comfort issues must be considered (Figure 9-1).

Flat-Barn Parlors

Flat-barn parlors (Figure 9-2) are normally built in existing buildings and are similar to switch milking in that cows are brought from a freestall barn or pasture to an existing barn to be milked. Rather than using all 50 stalls, some of the stalls would be used to milk cows, and other stalls would be removed to provide space for a holding area. For instance, eight stalls on each side of the barn could be left and four milker units used on each side. These eight units (four per side) would be used to milk half of the cows locked in the 16 stalls. When the first group of cows has been milked, the units are switched to the other eight cows and the just-milked cows removed from the barn, and eight more cows are brought from the holding area to be ready for the next shift of the milk machines. These flat barns are normally more labor efficient than switch milking in existing barns since the milking machine units do not need to be moved. To improve cow entry and exit from the milking-area, manure gutters are often filled or covered by gutter grates. To ensure good cow movement, gutter grates should be strong enough and correctly placed so the cow does not sense movement when weight is placed on them.



In back-out flat-barn parlors cows must back out of the stall after being milked; in walk-through flat-barn parlors, the cows can walk forward after being milked. Existing barns can often be converted to back-out flat-barn parlors for $10,000 to $15,000 if existing stalls can be used, whereas walk-through parlors may cost $40,000 or more if new equipment is purchased. Worker comfort in these parlors is often better than in stanchion barns, in that the cows may stand at a higher elevation and less kneeling is required, but they are not so comfortable as a true pit parlor. Initial cost, worker comfort, worker safety, worker efficiency, ability to implement correct milking procedures, and the expected amount of time the parlor will be used should be considered when selecting among these options. Since worker comfort, safety, and efficiency are less satisfactory in a flat-barn parlor than in a pit parlor, the cost of a pit parlor should be ascertained before building a flat-barn parlor.

Swing Parlors

In a swing parlor, one set of milking machines is installed and used to milk both sides of a pit parlor (Figure 9-3). A double-8 parlor would have eight milking machine units. Eight cows on one side of the pit would be milked first and then the units swung to milk eight cows on the other side. This is the parlor of choice for producers who want to milk cows fast with a low in vestment per animal. Parlors are normally of the herringbone type, with varying cluster spacing depending on the animal angle selected for positioning the cows. These parlors are often built with a simple, inexpensive rump rail to restrain animals. To keep construction costs low, this rump rail often does not have manure splashguards, the platform floor does not have gutter grates, and so on, to reduce manure splattering. Therefore, these parlors are often considered dirtier places to work than conventional parlors. Milk lines are normally mounted above the milker units (referred to as a high-line), which may have an impact on vacuum levels and increase the incidence of mastitis. Since units from one side must be taken to the other side, a slow milking cow on one side may cause the cow on the other side to have her unit attached after her milk let-down response.

Herringbone Pit Parlors

Herringbone parlors get their name from the angle at which cows are positioned with respect to the pit wall. Normally a row of cows is positioned at a 45[degrees] angle on each side of the parlor pit. Milker units are applied to the udder from the side of the cow, and this configuration allows an arm-type take-off to be used. With American Holstein cows, herringbone parlors require about 45 inches of parlor pit length per stall. This is less than auto-tandems and more than parallel parlors, and should be taken into account when building a large parlor. Since milking machines are applied from the cow's side, the animal can kick the operator more easily than she can in some other parlor types. Gutters and grates are normally used with herringbone parlors to catch manure and urine and to minimize manure splattering on the operator.


Parallel Pit Parlors

In parallel parlors, cows stand perpendicular to the pit wall, and milking machines are applied between the hind legs of the animal. Parallel stalls require only about 27 inches of pit length per stall and are normally chosen for large parlors to minimize walking distance. Parallel parlors are normally considered safer because stalls are built with a rear rail that prevents cows from kicking the operator. Since the milking machine must be attached between the legs of the animal, the operator must be careful to remove any manure from the milking machine claw to prevent contamination of the milk. No arm take-off has been designed for this parlor type, so a rope or chain take-off must be used. To minimize manure splattering, these parlors often have butt pans mounted on the rear of the stall to catch manure or urine.

In both parallel and herringbone parlors cows are loaded, milked, and released in batches. For instance, with a double-8, eight cows are loaded on a side, prepped, milked, and then released. This batch handling of cows can support a wide range of efficient milking procedures.

Milking Procedures and Routines Used in Parallel and Herringbone Parlors

The following terms refer to common milking parlor procedures.

Prep time--time taken to manually clean and dry the teat surface. Contact time-the actual time spent manipulating or touching teats, which is the source of stimulation for oxytocin release.

Prep-lag time--time between the beginning of teat preparation and the application of the milking machine.

Milking procedures--the individual events (i.e., strip, pre-dip, wipe, attach) required to milk a single cow.

Milking routines--define how an individual milker or a group of milkers carry out a given milking procedure (minimal or full) over multiple cows. In parallel and herringbone parlors, there are three predominant milking routines: group, sequential, and territorial.

Grouping milking routine--in a grouping routine, the operators perform all the individual tasks of the milking procedure on four or five cows. Once they have completed a group of cows, they move to the next group of available cows.

Sequential milking routine--operators split up the individual tasks of the milking procedure among themselves, and work as a team

Territorial milking routine--milkers are assigned units on both sides of the parlor and operate only the units assigned to them; they are not dependent on other milkers to perform specific tasks.

The two predominant milking procedures are minimal (strip or wipe, and attach) and full (pre-dip, strip, wipe, and attach). Milking procedures impact the number of cows per stall per hour in parallel, herringbone, and rotary parlors. In large parallel and herringbone parlors, cows per stall per hour were 5.2 when minimal milking procedures were used and 4.4 when full milking procedures were used. Cows per stall per hour declined from 5.8 to 5.3 when a full routine was used, compared to a minimal routine in rotary parlors (Armstrong, Gamroth, & Smith, 2001). In large parallel and herringbone parlors, milking procedures have a dramatic impact on the number of units one operator can handle. In 1997, Smith, Armstrong, and Gamroth published guidelines for the number of units that one operator could handle using a minimal and a full milking procedure. Using a full milking procedure, a milker could operate 10 units per side, compared to 17 units per side using a minimal milking procedure. These recommendations allowed four to six seconds to strip a cow, and four minutes to attach all the units on one side of the parlor.

In recent years, several milking management specialists have been recommending two to three squirts per teat (8-10 seconds) when stripping cows to increase stimulation and promote better milk letdown. Some of these management specialists believe that increasing the amount of stimulation reduces machine on-times. At present, a strong data set supporting this theory does not exist. An American Association of Bovine Practicioners (AABP) research update report by Johnson, Rapnicki, Stewart, Godden, and Barka (2002) indicated that milk flow rate decreased when cows that had been previously stripped were no longer stripped. If this change is implemented, producers will have to reduce the number of units one operator can manage per side (Table 9-1). The sequencing of the individual events of the milking procedure is critical. Rasmussen, Frimmer, Galton, and Peterson (1992) reported an ideal prep-lag time of 1 minute 18 second. Prep-lag times of 1-1.5 minute are generally accepted as optimal for all stages of lactation. Some of the advantages and disadvantages of minimal and full milking procedures are listed in Tables 9-2 and 9-3.

Three predominant milking routines are used in parallel and herringbone parlors (sequential, grouping, and territorial). These milking routines are presented in Figure 9-4. The use of territorial routines will reduce throughput 20-30 percent when compared to sequential routines (Smith, Armstrong, Gamroth, 1997). Grouping routines seem to be an alternative to sequential routines without sacrificing throughput. Sequential and grouping routines are demonstrated in Figure 9-5. In the planning of a parlor, the desired milking routine should be determined and procedures implemented that will be easy for employees to understand and follow.

Auto-Tandem Pit Parlors

Auto-tandem parlors are often referred to as side-openers because cows enter the milk stall from the side, off a lane that runs behind each row of stalls. In this parlor type, cows stand in a line, and the length of each stall must be as long as the cow being milked. Cows are loaded individually and are allowed to exit at random times. This is different than the parallel and herringbone parlors, which milk cows in groups. Since cows can exit when they are finished (they do not need to wait until the last cow in the group is finished), the number of cows milked per stall per hour is higher than with parallel or herringbone parlors. But because the stalls are longer, large parlors of this type are not recommended, which limits the maximum herd size to be milked with this type of equipment. Producers considering this option must consider the long-term growth potential of their operation and factor it into their buying decision. Since cows enter and exit at random times, it is difficult to efficiently implement certain recommended milking procedures.

Rotary Pit Parlors

In rotary parlors, cows enter from a fixed point, ride a rotating disk, and exit at a second fixed point (Figure 9-6). This technology is not new but has been regaining popularity lately with large operations. Cows seem to enjoy the ride and often fight to get on the rotating disk. Operators remain at fixed positions and cows pass by as the disk turns. One operator is usually required for each function, and training of milk machine operators is simplified because each employee has only one function to perform. After the milking unit is attached, the cow moves past the operator who attached the claw. If a milking machine liner slips or a milking machine claw falls off, a worker must leave his position and go to the problem machine to adjust or reattach it. The capacity of rotary parlors is limited by the time it takes to load each animal onto the disk. If a 10-second average load time is achieved, a theoretical throughput of 360 cows per hour could be expected. (Since not every stall will get filled as the disk turns, some cows will require a second trip around in order to be completely milked; and since the disk also must be stopped in case of problems, it will never reach this theoretical limit.) Smith et al. (1997) recommend sizing these parlors assuming 11-12 seconds per stall to load cows, with 80 percent of the theoretical throughput expected. Figure 9-7 shows the typical full and minimal milking routines for a 72-stall rotary parlor (using four operators for a minimal routine, and five operators for a full routine). Notice how the available unit on-time changes.




Rotary parlors have a reputation for milking large numbers of cows per hour if a minimal milking procedure is used. Research by Smith et al. (2003) shows that their throughput, on a cows-per-worker-hour basis, is less than other parlor types when a full-prep milking procedure is used, because of the number of workers needed. Rotary parlors usually require a larger building than herringbone or parallel parlors with the same milking capacity, and have higher equipment costs. Furthermore, expansion of the parlor is difficult. It should also be noted that if an operator leaves a pit, a replacement worker is needed or the parlor must be stopped. Since operators continuously perform the same repetitive task, workers are often rotated among functions to avoid operator boredom.

Robotic Milkers

The newest way to milk cows is with a robotic milker (Figure 9-8). Developed in Europe, robotic milkers have been used on several hundred farms for a number of years. They are currently being tested and sold, on a limited basis, in the United States and Canada. They hold a lot of promise for traditional producers who wish to increase herd size and milking frequency without adding hired labor. Price, milk quality issues, and current milk marketing regulations still need to be resolved.



Sizing a Milking System

Designing a dairy requires understanding the capacity of the milking system and the different factors that affect it. Throughput often increases by 8-10 percent when cows are switched from 2X to 3X milking, pre-dip milking hygiene reduces throughput by 15-20 percent, new parlors have 10-12 percent greater throughput than renovated parlors, and the average number of cows milked per operator per hour decreases as the number of operators increases. The expected throughput of parallel and herringbone parlors is normally between four and five turns (times filled per hour), depending on the operation's circumstances. For example, if a herd is milked three times per day using a double-12 parlor with clean cows, and 4.5 turns are expected, then all planning should be based on a 108 cows-per-hour throughput (24 stalls X 4.5 turns = 108 cph).

When selecting a milking system, both the initial and ongoing costs must be considered. You should compare the expected average annual total cost, cost per cow, or cost per hundredweight of milk shipped for each system. Be careful not to overestimate the useful life of milking equipment, which often must be replaced or upgraded in five to seven years because of wear and obsolescence.

Producers who are moving from traditional dairy operations to parlor systems tend to build parlors that are larger than needed. Producers often think that the extra parlor size will allow the herd to be milked quickly so they can move on to the other activities they are accustomed to doing. Owners in this situation should remember that if they do milk the cows, they are actually earning a wage equivalent to what a worker could be hired for. Often, after producers modernize their operations, the first employees they hire milk the cows. This is logical because milking is a repetitive task that employees can be easily trained to do. The producer who builds a parlor complex larger than needed therefore causes several problems: (1) the cost and payments are larger than needed; (2) extra cleaning materials, and so on, are required; and (3) it may be more difficult to find employees willing to work less than an eight-hour milking shift. Parlor size should be balanced with the other components of the dairy. Often a two-person crew is present during each milking even though one person can operate the parlor. This second person can decrease the milking shift length by moving groups of cows, policing freestalls, scraping manure, and giving the milker a break; plus he or she offers an element of security in case of an emergency. Selecting facility features and work schedules that integrate the needs of the total operation can in this way improve its overall efficiency.

Milking Center Components

A modern milking center consists of milking area, animal-holding pen, milking equipment area, milk storage or loading area, and often one or more offices. Each of these components should be located to minimize construction cost and labor utilization costs. Parlor complexes with equipment rooms and offices located on alternate sides of the milking parlor are often built to minimize the noise in offices, but they are more expensive than such facilities built on the end of the parlor building.

Operator Pits

Operator pits are normally eight feet wide between curbs. Larger parlors sometimes have wedge-shaped operator pits narrowing from about 10 feet wide at the breezeway to six feet at the other end. This arrangement offers two advantages: it gives people standing at the breezeway end a better view of the parlor, and it provides more space for cows to exit at the far end. The cow platform height should be sized for the type of people that will milk in the parlor, with 38-42 inches above the floor of the operator pit being typical. If in doubt, it is better to make the platform too high, because mats, and so forth, can always be used to raise the operator. Movable floors have become quite common in large parlors because of the extra comfort given to the milker (Figure 9-9). In parallel parlors, the operator pit floor should have about two inches of side slope from the center of the pit to the pit wall and 1 percent slope for the length of the parlor.

Subway (or basement) parlors (Figure 9-10), in which the milklines and some milking equipment are placed below the parlor pit or cow platform, increase the initial building cost but decrease parlor noise, decrease equipment cleaning needs, allow more flexibility in the placement of milklines and receiver jars, and allow for easier maintenance of milking equipment in large parlors with long operating schedules.

Parlors with rapid-exit stalls allow all cows in a group to move directly out of the milking stalls through individual gates or a raised barrier in front of the cows. Exit time is decreased and normally can be cost-justified on double-10 or larger parlors.

The amount and type of automation selected depends on the parlor size, labor availability, capital resources available, and individual preference. For most parlors, automatic detachers should be considered because of the labor efficiency gains and the standardization of milk claw removal that they provide. Other mechanization to consider includes crowd gates, electronic animal identification, sort gates, and indexing (which allows the front rail of the milk stall to adjust to animal sizes).


Holding Pens

A holding area is an integral part of all milking center systems (except switch milking). It should be large enough to hold the largest pen of cows to be milked, not only for the current expansion, but any future expansions contemplated. A minimum of 15 square feet of floor space per animal is recommended. To decrease the total milking shift length, most producers have another group of cows brought to the holding area before the first group has been finished. The milk machine operator can then finish one group and immediately start the next group. To accomplish this, the holding area capacity should be 125 percent of the size needed for one group. A series of gates and drover lanes must be designed so that animals from the two groups are not mixed up during milking.

The holding area should be sloped up to the parlor floor to encourage cows to stand facing the parlor; a slope of three to five percent is preferred. Adding a crowd gate to encourage animals to move into the parlor is also recommended. People-passes, which allow people to move through a fence opening, are not recommended in the holding area because cows may stick their heads in them and get jammed by a moving crowd gate. If an opening is desired into the holding area, a gate should cover it. Ventilation is extremely important; proper summer ventilation and use of fans and sprinklers can help minimize the stress on cows waiting to be milked. It has become common to cover holding pen floors with rubber alley mats to increase cow comfort.


Exit Lanes

In parlors with 15 or fewer stalls on a side, a three-foot-wide exit lane leading away from the parlor is sufficient. For large parlors a six-foot lane is suggested. In cold climates this lane may freeze, causing cows to slip and fall when exiting the parlor. Producers have addressed this problem by installing

* heated exit lane floors;

* wide exit lanes (Figure 9-11) with skid steer access to remove frozen materials;

* gated exit lane fences that can be opened to remove frozen materials; or

* a warm holding area, which prevents freezing.

The number and location of exit lanes varies by parlor type and the animal handling system being considered. Parlors in which cows are milked on two sides of an access lane (for example, the pit of a pit parlor) often have an exit lane from each side. This allows cows to exit the parlor without crossing over the access lane. If electronic sort gates are being considered, a parlor that allows cows to cross over the parlor pit before exiting, or allows cows from the two exit lanes to merge later, will support the need for one sort gate to select animals and one holding area for selected animals.


Foot Baths

Hoof care is a critical part of herd management. Foot baths in exit lanes have been used very effectively to reduce the incidence of foot-related problems. Placing two foot baths, one with clear water and a second with medicated solution, at least ten feet apart allows the first foot bath to clean the foot. The space between, which allows cows to defecate before reaching the second bath, makes the second foot bath more effective. The foot bath should be long enough to ensure that every foot of every cow is covered every time it is being used. Foot baths should be a minimum of eight feet long and support a minimum liquid depth of four inches throughout the length of the bath. Remember to have a water source easily accessible, and design foot baths that are easily cleaned (Figure 9-12).


To effectively monitor a modern dairy operation, good records are a must. A clean, comfortable working environment improves worker efficiency. A location near related activities minimizes the time needed for employees to access information and allows the manager to monitor the operation. Modern dairy equipment and the computers used by them should be housed in warm, clean areas. Rugs and foot-washing equipment should be strategically placed at entrances to reduce the amount of filth deposited in office and equipment areas. If resources are limited, office space may be minimized during early stages of an expansion, but long-term plans should allow for additions later.


Use of Existing Buildings to House Milking Centers

Producers considering the use of an old building to house a new milking center (Figure 9-13) should be very careful. Both options--placing the milking center in a new building or using an existing one--should be thoroughly evaluated and cost-compared. The usefulness, labor efficiency, and resale value of each option should be considered. Use of an old dairy barn to house a milking center can be an advantage if the barn is in good repair and is located on a site that supports the long-term needs of the dairy. Traditional producers can often install a pit parlor milking center in an old dairy barn for $50,000-$90,000, whereas the same parlor may cost three to four times that if placed in a new building at a new site. Use of an existing structure often is less expensive because the shell, electrical system, water system, and roads are already in place, but remodeling is often very costly and is notorious for cost overruns because of unforeseen difficulties. If an old barn is used, how will it be ventilated (Figure 9-14), and at what cost? When considering constructing a new building to house a milking center, a new site away from existing structures is almost always a good decision.

Milking Procedure Implications

There are many different ways to milk cows. Experts agree that the key element is to be consistent in whatever procedure you select. Circumstances vary by farm, allowing some herds to use procedures that would not work in other herds. Sometimes circumstances change, requiring procedural changes. Understand the basics of milk let-down, mastitis transmission, and so on, and their implication on milking procedures for each system being considered. Investigate the effects on labor usage and comfort with the different milking center options considered. Look at the work-routing implications of different milking systems, as in the following examples, before making your decision.

* Cows are milked in batches with parallel and herringbone parlors, allowing great flexibility in procedures.

* Milkers stand and perform functions (apply pre-dip, wipe udder, attach milker claw, etc.) as cows move by on rotary parlors; this means that adding an additional function often means adding another worker.

* Walk-through flat parlors with one stall per milker unit, and auto-tandem parlors, process cows individually. These parlors require milkers to move about the parlor chasing the next cow that is ready. As a result, full-prep procedures are difficult, and worker efficiency decreases.



Efficiency Implications

When the different milking center designs are being considered, the issues of air-flow, cow-flow, and people-flow are critical. Proper ventilation of both parlor and holding area is important to reduce stress on cows and workers. Remember to think through both warm- and cold-weather implications. Concentrate on cow-flow issues relating to getting cows into and away from the parlor multiple times per day, plus any sorting and handling needed. Human access lanes, people-passes in gates and fences, and quick-opening gate latches all improve labor efficiency and reduce worker frustration.

Milking System Performance

A recent survey of Wisconsin producers who increased herd size by at least 40 percent from 1994 to 1998 showed performance values for different systems selected (Wagner, Palmer, Bewley, and Jackson-Smith, 2001). Table 9-4 shows that the smaller, less-expensive milking facilities selected by producers with smaller herds do not achieve the labor efficiency that pit parlors in new barns achieve. The average herd size for these groups ranged from 65-411 cows, with 7-20 miker units costing $4,191-15,832 per milking unit, and they can handle 21-43 cows per milker hour, where milkers include both people actually milking and those moving cows.

When only the producers who selected pit parlors are analyzed (Table 9-5), parallel parlors appear to be the most common pit parlor type with Wisconsin herd owners that expanded. Producers selecting herring bone parlors reported paying less per stall for their milking center, which indicates that a large percentage of these are using old equipment or placing the parlors in existing buildings. Performance and satisfaction for parallel and herringbone parlors are very similar.

Note: the superscripts shown in Tables 9-4 and 9-5 indicate whether the means shown within the table are significantly different (P G 0.05) (Wagner et al., 2001). If two mean values are significantly different, they will have a different superscript, and the largest value will have the superscript a. (An ab superscript is not significantly different from an a or b value, but is significantly different from a c value, etc.). For example, the average number of milking units for pit parlors in new buildings was 20, which was significantly larger than the average number of units (14) for pit parlors in old barns. Larger values are often good, but for some, like linear SCS (Somatic Cell Score), the smaller number is better. Parlor Performance

Parlor Performance

It is suggested that producers understand the principles of monitoring parlor performance and use them when selecting the size and type of parlor to build. Planning for labor needs and using these plans in the development of your feasibility studies is a very important part of the process. When a facility (or facility change) is being planned, it is important to understand the roles of both the manager and the employees in the production of high-quality milk, and to select design features that support the accomplishment of this task in an efficient manner.

Measuring Parlor Performance

Everything revolves around the parlor. Because parlors are fixed assets, increasing their use increases profits. Milking cows 21-22 hours a day, depending on the time required for properly washing the system, makes the best use of this asset. Milking parlor performance has been evaluated by time and motion studies (Armstrong & Quick, 1986) to measure steady-state throughput (cph). Steady-state throughput does not include time for cleaning the milking system, maintenance of equipment, effects of group changing, and milking hospital strings. These efficiency measurement studies also allow us to look at the effects of different management variables on milking parlor performance. Some typical efficiency measurements are cows per hour (cph), the total number of cows milked in one hour; cows per labor hour (cplh), cph divided by the total number of milkers; milk per hour (mph), the total amount of milk harvested in one hour; milk per labor hour (mplh), mph divided by total number of milkers; and turns per hour (tph), the number of times cows enter and exit a parlor in one hour (also called parlor throughput).

Understanding these milking parlor efficiency measures can be very beneficial in making the correct parlor buying decision. When parlor performance is evaluated, parlor throughput can be further broken down into several individual time measurements, such as the following.

* Time from exit of the previous group until the first cow is touched (only if forestripping before pre-dipping)

* Time from exit of the previous group until the first cow is pre-dipped

* Time from pre-dipping to drying (check minimal "kill time")

* Time from exit of the previous group until the first unit is attached

* Time from exit of the previous group until all units are attached

* Time from exit of the previous group until all units are detached

* Time from when all units are detached until exit again

Measuring Effectiveness of Routines and Procedures

Regardless of the milking procedure and routine chosen, employees will be more receptive to and effective at performing procedures if they have a role in developing them. Employers can learn from employees, and incorporating workers in decisions that affect their work improves morale and the working environment in general. Employee input is crucial! The easier a job is to understand, the easier it is to manage. Keeping the routine as simple as possible and ensuring that employees perform equal amounts of work will minimize employee turnover and improve labor efficiency. The challenge for many dairies is to motivate milkers to properly clean teats prior to attaching units. Conducting milker meetings to clearly explain the procedures expected in the parlor, and why each step is important, has proven successful for numerous dairies. Milking procedures should be written (in the language of choice) and given to all milkers prior to performing the procedure. It is also beneficial to have procedures posted on the wall in the parlor for everyone to see.

There are numerous measures of milk quality that management must clearly understand. Facilities should be designed, goals established, and procedures implemented that facilitate acceptable levels for each of these mea sures. Table 9-6 explains typical milk quality, udder health, and general clean-in-place (CIP) sanitation measurements (standard plate count, laboratory pasteurized count, coliform count, preliminary incubation count, somatic cell count, clinical mastitis, teat and teat-end condition, added water, antimicrobial drug residues, and sediment) and the influence on these measures of both management and employees (adapted from VanBaale, Fredell, Bosch, Reid, & Sigurdson, 2001).

If milk quality and udder health goals are being met, then the milking procedure and equipment being used is most likely acceptable. Additionally, teat and teat-end condition scoring should be done on a regular basis to evaluate the health of the udder.


Selecting the correct milking center is not easy. It can be a very time consuming and confusing because of the many options available. Many different features exist that can improve operation efficiency, but features must be selected based on their relative value and the total resources available. When considering milking center designs, air-flow, cow-flow, and people-flow issues are critical. Proper ventilation of both the parlor and holding area is important to reduce stress on cows and workers. Remember to think through both warm- and cold-weather implications.

Concentrate on cow-flow issues relating to getting cows into and away from the parlor multiple times per day, plus any sorting and handling procedures needed. Provide human-access lanes, people-passes in gates and fences, and quick-opening gate latches to improve labor efficiency and reduce worker frustration. Remember that each feature should be evaluated not only on its own merit but also on how it complements other decisions with respect to both the initial capital cost and long-term labor implications. Since the system selected must be used for a long time, a thorough evaluation of available options and strategies is required.

Tour existing farms and talk to producers and the milkers who use the equipment every day. Go to farms during milking, and watch cows and milkers to determine the comfort of each. Watch milking procedures and ask about somatic cell count and mastitis. If possible, actually milk in different types of milking centers. Keep an open mind and take notes about the advantages and disadvantages of each system. Think about the implications associated with each system, and try to envision things that could happen to require you to change your expected milking procedure. For example, what are your options and costs if you select a milking center design thinking that no udder preparation will be needed, and then you encounter a severe mastitis problem that requires going to a full-prep procedure? Select a system that offers the flexibility needed, falls within your budget, and complements your current and long-term goals.


1. List the advantages and disadvantages of minimal milking procedures. List the advantages and disadvantages of full milking procedures.

2. What is one cause of mastitis? How can milking procedures be changed to reduce incidence of mastitis?

3. Using the facility descriptions in this chapter, create diagrams for switch, flat-barn, swing, parallel, herringbone, auto-tandem, and rotary parlors. Be sure that each diagram identifies cattle entry and exit points, placement of milking equipment, rump rails, and other pertinent features.

4. For each of the parlor types in question 3, explain how the structure of the parlor affects milking routines and animal health.

5. Imagine a dairy operation with a double-12 parallel pit parlor that is being switched from minimal to full milking procedures. On average, what is the dairy's new throughput? How much did the throughput decrease?

6. What are the five ways to measure parlor performance?

7. What are five key design features of an animal holding pen?


Armstrong, D. V, & Quick, A. J. (1986). Time and motion to measure milk parlor performance. Journal of Dairy Science, 69 (4), 1169-1177.

Armstrong, D. V, Gamroth, M. J., & Smith, J. E (2001). Milking parlor performance. In Proceedings of the 5th Western Dairy Management Conference, Las

Vegas, NV (pp. 7-12). Manhattan: Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Johnson, A. P, Rapnicki, P, Stewart, S. C., Godden, S. M., & Barka, N. (2002). A field trial to evaluate the effects of fore-stripping on milk-flow rates. Abstract in Proceeding of the American Association of Bovine Practicioners 35th Annual Convention, Madison, WI. Rome, GA: American Association of Bovine Practitioners.

Rasmussen, M. D., Frimmer, E. S., Galton, D. M., & Peterson, L. G. (1992). Influence of premilking teat preparation and attachment delay on milk yield and milking performance. Journal of Dairy Science, 75, 2131.

Smith, J. E, Armstrong, D. V, & Gamroth, M. J. (1997). Labor management considerations in selecting milking parlor type and size. In Proceedings of the Western Dairy Management Conference, Las Vegas, NV (pp. 43-49). Manhattan: Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Smith, J. E, Harner, J. P, Armstrong, D. V, Fuhrman, T, Gamroth, M., Brouk, M. J., et al. (2003). Selecting and managing your milking facility. In Proceedings of the 6th Western Dairy Management Conference, March 12-14, Reno, NV Manhattan: Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Stewart, S., Godden, S., Rapnicki, P, Reid, D., Johnson, A., & Eicker, S. (2002). Effects of automatic cluster remover settings on average milking duration, milk flow, and milk yield. Journal of Dairy Science, 85, 818-823.

VanBaale, M. J., Fredell, D., Bosch, J., Reid, D., & Sigurdson, C. G. (2001). Milking-parlor management, quality milk production, from harvest to home. St. Paul, MN: Ecolab.

VanBaale, M. J., & Smith, J. E (2004). Parlor management for large herds. Charlotte, NC: National Mastitis Council. [Paper available upon request:].

VanBaale, M. J., Smith, J. E, Armstrong, D. V, & Harner, J. P, III (2004). Making decisions regarding the balance between milk quality, udder health, and parlor throughput. [Technical paper]. Manhattan: Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Wagner, A., Palmer, R. W, Bewley, J., & Jackson-Smith, D. B. (2001). Producer satisfaction, efficiency and investment cost factors of different milking systems. Journal of Dairy Science, 84, 1890-1898.
TABLE 9-1 Time (in seconds) required for individual events
of the milking procedure.


Event     Minimal *   Full    Full with 10-Sec
                               Contact Times

Strip        4-6       4-6           10
Pre-dip                6-8          6-8
Wipe         6-8       6-8          6-8
Attach       8-10      8-10         8-10
Total       12-18     24-32        30-36

* Strip or wipe, and attach

TABLE 9-2 Advantages and disadvantages of a minimal milking routine.

Advantages                                     Disadvantages

Successful when cows enter the       Compromises teat skin sanitation
milking parlor clean and dry

Time required to milk the herd may   Machine on-time may be prolonged
be decreased (total milking time)

Steady-state throughput increased    May require milkers to decide when
                                     extra cleaning of dirty teats is
                                     required; can cause lower milk
                                     quality and higher mastitis when
                                     compared to "full hygiene"

TABLE 9-3 Advantages and disadvantages of a full milking routine.

Advantages                  Disadvantages

Maximizes teat sanitation   Uses four separate procedures (or can
and milk letdown            combine into two or three procedures)

Minimizes machine on-time   Results in lower cow throughput or
                            higher labor cost

Maximum milk quality        Requires more milker training to
                            maximize results

TABLE 9-4 Milking performance of different system types.

                                Stall Barn      Flat Parlor
                               with Pipeline    in Old Barn

Herds, no.                                65              52
1998 mean herd size                      117             157
1998 RHA milk, lbs                20,684 (c)     21,397 (bc)
Linear somatic cell score           3.02 (a)       2.97 (ab)
Number of milking units                7 (d)           9 (c)
Number of milkers                    2.4 (a)        2.2 (ab)
Cows per hour                         47 (c)         55 (bc)
Cows per milker hour                  21 (d)          27 (c)
Time spent milking *                3.03 (c)       3.92 (ab)
Physical comfort of milker *        2.45 (c)        3.83 (b)
Milk quality *                      3.28 (b)        3.75 (a)
Safety of operator *                3.31 (c)        3.40 (c)
Cost per milking unit             $4,191 (b)      $4,954 (b)

                               Pit Parlor in   Pit Parlor in
                                 Old Barn      New Building

Herds, no.                                73             107
1998 mean herd size                      212             411
1998 RHA milk, lbs               22,207 (ab)      23,073 (a)
Linear somatic cell score          2.86 (ab)        2.78 (b)
Number of milking units               14 (b)          20 (a)
Number of milkers                    2.0 (b)        2.1 (ab)
Cows per hour                         61 (b)          83 (a)
Cows per milker hour                  34 (b)          43 (a)
Time spent milking *                3.78 (b)        4.12 (a)
Physical comfort of milker *       4.10 (ab)        4.32 (a)
Milk quality *                      3.66 (a)        3.70 (a)
Safety of operator *                4.01 (b)        4.38 (a)
Cost per milking unit             $6,500 (b)     $15,832 (a)

* Average satisfaction reported on a scale of 1 (very dissatisfied)
to 5 (very satisfied)

TABLE 9-5 Milking performance of different pit parlors.

                               Auto-Tandem   Herringbone      Parallel

Herds, no.                               7            67           104
1998 median herd size                  190           275           245
1998 RHA milk, lbs                  22,146        22,715        22,721
Linear somatic cell score             2.76          2.81          2.82
Number of milking units             10 (b)        17 (a)        18 (a)
Number of milkers                      2.1           2.0           2.2
Cows per hour                           60            71            75
Cows per milker hour                    30            38            40
Turns per hour                    6.20 (a)      4.13 (b)      4.44 (b)
Time spent milking *                  4.00          3.89          4.02
Physical comfort of milker *          4.71          4.05          4.30
Milk quality *                        3.71          3.74          3.62
Safety of operator *                  4.14          3.85          3.88
Cost per milking unit          $17,268 (a)   $8,944 (b)    $13,201 (a)

* Average satisfaction reported on a scale of 1 (very dissatisfied) to
5 (very satisfied)

TABLE 9-6 Milk quality, udder health, and sanitation measures.

Standard plate           The SPC is the total quantity of viable
count (SPC)              bacteria in a millimeter (ml) of milk. The
                         SPC is a reflection of the sanitation used in
                         milking cows, the effectiveness of system
                         cleaning, and the proper cooling of milk.
Employee influence       The manner in which cows are prepared for
Management influence     The quality of water and the ability of the
                         water heater to produce water of the
                         appropriate temperature.

Laboratory pasteurized   The LPC is a measure of bacteria that survive
count (LPC)              pasteurization. This group of bacteria has an
                         influence on the flavor and shelf life of
                         dairy products. The general sanitation of the
                         CIP system and the condition of the
                         rubberware can contribute to a high LPC.
Employee influence       The manner in which cows are prepared for
                         milking, as well as attention to the
                         condition of rubber goods and the wash-up.
Management influence     The bacterial quality of the wash water and
                         the choice of detergents and sanitizers.

Coliform count (CC)      The CC measure reflects the extent of fecal
                         bacteria exposure of milk. Coliform bacteria
                         can enter milk as a result of milking dirty,
                         wet cows or may result from coliform growth
                         within the milking system.
Employee influence       Employee hygienic practices have substantial
                         control over the CC. The milking of clean and
                         dry udders will limit exposure.
Management influence     CC problems may be associated with a poor CIP

Preliminary incubation   The PI count is a measure of bacteria that
count (PI)               will grow well at refrigerator temperatures.
                         The PI is controlled by strict cow sanitation
                         and excellent system cleaning.
Employee influence       Udder preparation and sanitation have a
Management influence     positive effect on the PI. The efficacy of
                         the CIP washing system.

Somatic cell             The SCC on bulk tank milk and individual cow
count (SCC)              milk is a direct measure of the severity of
                         mastitis (udder infection). The incidence and
                         prevalence of the disease in the dairy is
                         subject to a variety of factors. In general,
                         the SCC reflects a subclinical or nonvisible
                         form of the disease.
Employee influence       The manner in which the cows are milked can
                         have a significant influence on the rate of
                         new infections.
Management influence     The condition of the cow bedding environment
                         and the commingling of chronically infected
                         cows with noninfected cows.

Clinical mastitis        A proportion of mastitis infections become
                         severe enough to become clinical. The
                         clinical signs include changes in milk
                         appearance and may include signs of disease
                         in the animal as well. Milk from cows with
                         clinical mastitis cannot legally be included
                         in the commercial supply. It is the milker's
                         responsibility to assure that the disease is
                         detected early and the milk is diverted for
                         discard or noncommercial use.
Employee influence       The employee has an influence on the manner
                         in which cows with clinical mastitis are
                         managed. Effective mitigation of the disease
                         depends on prompt detection and management. A
                         delay of 8-12 hours can result in the
                         incorporation of poor quality milk into the
                         commercial milk and may result in greater
                         disease costs.
Management influence     Type of teat dip used, the condition of the
                         cow bedding environment, and the commingling
                         of chronically infected cows with noninfected

Teat and teat-end        The condition of teats is a direct reflection
condition                of the cow's environment, the use of teat
                         dips, equipment settings, functionality, and
                         upkeep. In addition, milking procedures and
                         how well they are being followed impact teat
                         and teat-end condition.
Employee influence       Adequately covering all of the teats,
                         performing basic equipment checks and
                         maintenance, and following a well-designed
                         milking SOP (standard operating procedure) to
                         the letter.
Management influence     Type of teat dip used, the condition of the
                         cow bedding environment, implementing a well
                         designed milk procedure, and maintaining
                         properly functioning equipment in the milking

Added water              Milk is routinely tested for added water,
                         using the freezing-point test. Dishonest
                         producers sometimes add water to milk in
                         order to increase the volume. Water may be
                         added accidentally to milk by failure to
                         drain the milking system fully before the
                         milking begins.
Employee influence       During wash-up and sanitation of the milking
                         system, the employee can ensure that all
                         excess water is drained from the system. In
                         the case of farms that have a several-hour
                         period between milkings, standing water in
                         the system may also be associated with
                         elevated bacterial counts.

Antimicrobial drug       Most antimicrobial drug residues are not
residues                 tolerated in milk; a few have legal
                         tolerances, although the levels are extremely
                         low. The type of drug and the manner of its
                         application can greatly influence the
                         potential for milk residues. Regulatory
                         scrutiny has made dairy producers
                         increasingly accountable for eliminating drug
                         residue in milk.
Employee influence       Dairy farm management that instructs the
                         employee to medicate cows for specific
                         problems also must expect that the employee
                         will be able to withhold bad milk from the
                         commercial supply. This employee must know
                         which cows are medicated and how long the
                         milk is to be withheld. Some dairy farm
                         employees are instructed in the use and
                         interpretation of milk residue tests.

Sediment                 The sediment in milk is a measure of the
                         general filthiness of cows. This fine debris
                         moves through the farm milk filter and is
                         detected by the milk processor. High
                         sediments may be associated with higher
                         bacteria counts. However, some bedding
                         materials, like river sand, may contain very
                         fine particles that are measured in the
                         sediment evaluation.
Employee influence       The general methods for cow and udder
                         preparation will affect the amount of
                         sediment in the milk.
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Author:Palmer, Roger W.
Publication:Dairy Modernization
Date:Jan 1, 2005
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