Relocating or expanding a dairy facility is a process that requires a tremendous amount of time and planning. Owners or managers of dairies will go through a number of steps including:
•writing a business plan
•selecting location or site
•permitting and legal issues
•hiring and training employees
•developing management protocols for the dairy
•planning for information flow
This article will discuss designing and locating a dairy facility to maximize labor efficiency and cow performance by focusing on milking parlors, cow housing, grouping strategies and site selection.
Many owners and managers who have made the decision to expand prefer to use the design-build concept or a design team. This concept specifies that management employs a design consultant to work with the management specialist in developing a basic dairy design and program plan to meet the client’s needs. The design team consists of a consulting engineer and supporting dairy management specialists. Dairy management specialists could include dairy extension faculty, financial advisers, nutritionists, milking equipment manufacturers and veterinarians. This team approach is an efficient way to integrate desired management into physical facilities.
Options for the milking parlor
Sizing parallel and herringbone milking parlors
Typically, milking parlors are sized so cows can be milked once in eight hours when milking 2X per day; six and a half hours when milking 3X per day; and five hours when milking 4X per day. Using these criteria, the milking parlor will be sized to accommodate cleaning and maintenance of the parlor. The facilities or cow groups are determined based on milking one group in 60 minutes when milking 2X, 40 minutes when milking 3X and 30 minutes when milking 4X. Group size is slightly adjusted to be divisible by the number of stalls on one side of the milking parlor.
Having as many occupied stalls as possible per cycle maximizes parlor efficiency. Typically, it is assumed the milking parlor is turned over 4.5 times per hour during milking. The average number of cows milked per hour can be calculated using the following formulas:
Total number of parlor stalls x 4.5 = cows milked per hour (CPH)
Number of milking cows = CPH x milking shift length (hours)
Sizing rotary parlors
The performance of rotary parlors is influenced by entry time (seconds per stall), number of empty stalls, number of cows which go around a second time, entry and exit stops and the size of the parlor (number of stalls). The entry time will determine the maximum number of cows that can be milked per hour. For example, if the entry time is 10 seconds, the maximum throughput will be 360 cows per hour (3,600 seconds per hour/10 seconds per stall = 360 cows per hour). This is referred to as theoretical throughput.
Theoretical throughput assumes the parlor never stops, cows are milked out in one rotation and a new cow occupies every stall at entry. In reality, there are empty stalls, cows not milked out in one rotation and times when the rotary table is stopped. As the number of empty stalls, cows making a second trip around and number of stops increases, the percent of theoretical throughput is decreased.
The number of stalls or size of the rotary parlor affects the available unit on time. A rotary parlor must be large enough to allow approximately 90 percent of the cows to be milked out in one trip around the parlor.
In reviewing data available today, rotary parlors should be sized at an entry time of 11 to 12 seconds per stall rotation and 80 percent of theoretical throughput. The parlor should be large enough to allow nine minutes of available unit on time.
Selecting parlor type
Currently, herringbone, parallel and rotary parlors are the three predominant types of parlors constructed on large dairies today. Earlier research would indicate that similar-sized parallel parlors outperformed herringbone parlors. The square footage required to house the milking parlor is influenced by parlor type.
The square footage requirement for parallels range from 1,890 to 5,300 square feet, while the square footage requirement for rotary parlors ranges from 3,025 to 9,216 square feet. Producers need to compare the construction cost of the different parlor types they are considering.
Equipment dealers are estimating basic equipment inside the parlor milk line, wash line, basic detacher and stall at $3,000 per stall for herringbone and parallel parlors and $3,400 for a rotary parlor. In parallel and herringbone parlors, the operator pit can be constructed to allow additional stalls to be added as the dairy expands.
Expanding rotary parlors is difficult. The operator pit can be constructed in parallel and herringbone parlors to allow additional stalls to be added as the dairy expands. In parallel and herringbone parlors, an operator can leave the parlor and the other operators can continue to milk cows at a slower pace. In a rotary parlor, if one operator needs to leave the parlor, he or she will have to be replaced by another operator.
One versus two parlors
Some research indicates two smaller parlors are more efficient than one larger parlor. One study compared two double-20 parallels versus one double-40 parallel. The net parlor return over 15 years was $908,939 greater in the two smaller parlors versus one large parlor. The initial cost of constructing two double-20 parallels was $22,227 higher than constructing one double-40 parlor. Constructing two parlors also allows producers to construct the dairy in phases.
Holding pens are designed based on 15 to 17 square feet per cow with a minimum capacity of one group of cows. If the wash pen is at a 90-degree angle to the cow traffic lane or the group size is greater than 200 cows, the area per cow should be increased to 16 to 17 square feet per cow. When a wash pen is not used, oversizing the holding pen by 25 percent allows a second group to be moved into the holding pen while the crowd gate is pulled forward and the first group is finishing being milked.
Wash pen design
The design and management of the wash pen is very important in U.S. dairies. With regulations on dairy water use and Environmental Protection Agency (EPA) manure regulations being put in place, wash pen use will come under additional scrutiny.
Wash pen use is essential in open-lot dairies. Many new freestall barns are being built without wash pens and depend on proper freestall management to deliver clean cows to the milking parlor.
The necessary area per cow for proper cow cleaning will depend upon several factors:
1. If the wash pen is at a 90-degree angle to the cow traffic lane, additional area is necessary to allow the cows to properly fit into the wash pen.
2. As group size increases, the area per cow increases. With group size up to 200 cows, a wash pen of 15 square feet per cow is adequate. With groups above 200 cows, 16 to 17 square feet per cow will provide adequate space.
Design of the sprinkler system is essential for adequate cow cleaning. With solid (concrete or metal) sidewalls, cows will face toward the parlor. This puts the udder next to the wall. A wash line should be placed 18 to 24 inches from the sidewall and use a pop-up sprinkler design. Such sprinklers are not as efficient as impact sprinklers. However, if all impact sprinklers are used, cows against the wall will not be cleaned well.
After placement of the outside row of sprinklers, the remaining sprinklers should be placed on a 5-foot-by-6-foot grid. For example, a 40-foot wide holding pen with outside rows 2 feet from the sidewalls would have five rows of sprinklers spaced 6 feet apart and 5 feet top to bottom.
Use a three-stage timer to operate the sprinklers. The timings will effect the amount of water used. This wash system is the largest user of water on the farm. Water use will vary from 18 to 30 gallons per cow per wash.
Drip pen design
Drip pen area will range from 15 to 17 square feet per cow. Size the drip pen to hold 100 percent of the corral or group size. This allows adequate time for udders to dry. The minimum size of a drip pen would be two complete turns of the milking parlor. For example, a double-20 parlor should have a minimum size to hold 80 cows (1,200 square feet). This would allow 24 to 30 minutes from the time in the wash pen to parlor entry.
Exit lane width is dependent on the number of stalls on one side of the milking parlor. In parlors with 15 stalls or less per side, a clear width of 3 feet is acceptable. For parlors containing more than 15 stalls per side, a clear exit lane width of 5 to 6 feet is desired.
Operator pits are typically 8 feet wide between curbs. In a wedge configuration, operator pits are typically 6 feet wide at the holding pen and 10 feet wide at the breezeway. The cow platform is 38 to 40 inches above the floor of the operator pit.
Provisions should be made to allow for floor mat thickness, if mats are to be used. The curb of the cow platform typically overhangs the operator pit wall 9 to 12 inches, depending on the size of the parlor. Normally, the operator pit and cow platform should have a 1 percent slope to the rear of the milking parlor. Operator pits typically have 2 inches of side slope from the center of the pit to the pit walls.
Constructing the milking parlor shell
There are several options available when constructing the shell of the milking parlor. If no future expansion is planned, the building can be constructed with no room for expansion. This often is done in situations in which acreage is not sufficient for expansion.
When long-term plans include expansion, the shell can be constructed with room to add a second parlor or add stalls to an existing parallel or herringbone parlor. If a second parlor is added, usually the two parlors will share a common equipment and milk storage facility. If additional stalls will be added to a parlor, space should be left in the front of the parlor to reduce cow entry time and allow installation of new stalls without impeding current milking routines. The final size of the holding pen (number of cows per group) should be sized for the total number of cows that will be milked after the expansion.
The milking facility should be properly ventilated to maintain employee and cow comfort. Office, meeting room, break room and restroom facilities should be incorporated to meet the needs of management.
Selecting cow housing
The predominant types of cow housing on large dairies in the United States are drylots and freestalls. This decision is based on climate, management style and equity available for constructing dairy facilities. Typically, drylot facilities can be constructed where the moisture deficit (annual evaporation rate minus annual precipitation rate) is greater than 20 inches annually. However, frequency and severity of winter rainfall and blizzards is becoming the key selection criteria. These facilities would provide 500 to 700 square feet per lactating cow, depending on the evaporation rate, with 40 square feet of shade per cow.
Windbreaks are constructed in areas where winter weather is severe. It is important to realize that drylot housing does not allow managers the luxury of managing the risk Mother Nature can present in the form of rain, snow and severe windchill. The advantage of drylot facilities is the lower capital investment per cow as compared to freestall housing.
Freestall housing usually is selected to minimize the effect of weather changes and to improve cleanliness and cow comfort. Providing a clean, dry bed is essential to minimize the incidence of mastitis in the herd. Comfort refers to providing a comfortable bed and the correct freestall dimensions. This makes it easy for the cow to move in and out of the stall and to lie comfortably in the stall. The disadvantage of freestall housing is the cost of constructing freestall housing and the costs associated with maintaining the beds.
Selecting and locating freestall barns
Several options are available when selecting freestall housing for lactating dairy cows. Some of the options include 2-row, 3-row, 4-row or 6-row freestall barns. Access to feed is reduced by 11 inches per cow in 3- and 6-row barns when compared to 2- and 4-row barns. The heat load per stall is greater in 3- and 6- versus 2- and 4-row barns at stocking rates of 100 to 130 percent.
The advantage of 2-row or 4-row freestall barns is access to feed, more square feet per cow and a lower heat load per stall in the barn. The advantage of 6-row barns is cost; however, producers should be concerned about the level of heat stress and the limited feeding area. Providing supplemental cooling in 6-row barns may be more critical due to the reduction in square feet per stall.
Ventilation and orientation of freestall barns
Proper ventilation is essential in a freestall barn. Freestall housing should be constructed to provide good natural ventilation. Sidewalls should be 12 to 14 feet high to increase the volume of air in the housing area. The sidewalls should have the ability to open 75 to 100 percent. Fresh air should be introduced at the cow’s level.
Curtains on the sides of freestall barns allow greater flexibility in adjusting the environment around the cow. Since warm air rises, steeper-sloped roofs provide upward flow of warm air. Roof slopes for freestall housing with gable roofs should be 4/12. Gable roofs with slopes less than 4/12 may have condensation and higher internal temperatures in the summer.
Providing openings on the end walls in addition to alley doors will improve summer ventilation. Gable buildings should have a continuous ridge opening to allow warm air to escape. The ridge opening should be 2 inches for each 10 feet of building width. Naturally-ventilated buildings should have a minimum of 100 feet between structures and preferably 1.5 to 2 times the building width.
Freestall barns are typically oriented east to west to take advantage of sun angles and provide afternoon shade. Barns constructed north to south will have an overhang on the west side producing desirable shade for stalls on the west side of the barn during the afternoon. Freestall barns should be located within recommended walking distances to the milking center but not restrict natural ventilation.
Facilities need to be sited to minimize the distance cows have to walk to and from the milking parlor. A forced walk in drylot housing would be from the gate of the housing area to the gate of the holding pen. Field observations in drylot facilities indicate the maximum forced walking distance should be 1,000 feet for 2X milking, 700 feet for 3X milking and 500 feet for 4X milking in drylot dairies.
Field observation in freestall buildings reveal cows begin to bunch up about halfway through the pen. It is not known if this bunching causes additional stress as compared to cows exiting drylot housing. So at this time, we would figure one-half alley length plus the distance from the top of the pen to the holding pen as forced walk distance in freestall barns.
Cow traffic lanes
The width of cow traffic lanes should be sized according to group size. When group size is less than 200 cows, 14-foot traffic lanes are typically used. Lane width is increased to 16 feet for group sizes from 200 to 300 cows and to 20 feet when group size is greater than 350 cows.
High-producing dairy cows can consume between 30 to 50 gallons of water per day. Water should be provided to cows leaving the milking parlor. In parlors which are double-25s or smaller, one 8-foot trough is usually sufficient. In parlors larger than double-25s, two 8-foot troughs are commonly used. In freestall housing, water should be located at every crossover. There should be one waterer or 2 feet of tank perimeter for every 10 to 20 cows. In drylot housing in the Southwest, the following formula has been used to calculate the tank perimeter needed:
Group size x .15 x 2 = tank perimeter in feet
The water system must be able to provide 75 to 100 gallons per cow per day. Peak flow rate is determined by number of waterers, assuming 100 percent utilization or milk parlor usage during cleaning. A minimum size well is probably 10 gallons per minute per 100 cows, with 20 to 30 gallons per minute per 100 cows being preferred.
How many crossovers do I need?
Recommended distances between crossovers range from 60 to 160 feet. A good rule of thumb is to provide crossovers every 100 feet or every 25 stalls. Crossovers are typically 10 to 12 feet wide. However, if a waterer is located in the crossover, consider increasing the width to 14 feet to allow cows to easily pass behind drinking cows.
Producers often reduce the number of crossovers in freestall barns to reduce construction costs. Reducing the number of crossovers limits the cow’s access to feed and water. It also reduces the total length available to construct the feedline. Very few producers stock freestall barns at one cow per stall. The tendency is to overstock freestall facilities. Therefore, reducing the number of crossovers or the width of crossovers restricts access to feed and water and limits the space for cows at the feedline. The bottom line is that the cows suffer when the number of crossovers is reduced.
Recommended stall dimensions
The dimensions used for constructing freestalls are a compromise between cow comfort and cow cleanliness. The challenge is to construct stalls that make it easy for cows to lie down and get up naturally and comfortably while positioning the cow to urinate and defecate in the alley. Stalls should be wide enough that cows normally do not bump or push on stall partitions in any way when rising or lying, but stalls that are too wide may allow cows to turn around or lie diagonally.
Stalls that are too long may allow lying too far forward unless brisket boards are used. These conditions increase the possibility of manure being deposited on the stall bed, dirtying bedding. In hot climates, consideration to heat build-up in the freestall area may lead to wider (48 inches) and longer (8 feet) freestalls.
With two rows of freestalls placed head-to-head and designed for space sharing, stall partitions usually are mounted on individual posts to allow for unrestricted open space for the forward lunge into the adjacent stall space. It is important that building support posts are located at multiples equivalent to stall width. This will prevent building support posts from obstructing the lunge space. Freestall width should determine building post spacing, not vice versa.
The size and number of cow groups on a dairy are critical planning factors. Factors affecting the number and types of groups are largely associated with maximizing cow comfort, feeding strategies, reproduction and increasing labor efficiency. Lactating cows (100 percent) are allotted to one of four groups; healthy (92 percent), fresh (4 percent), sick (2 percent) or slow milkers and lame (2 percent). Healthy cows should account for 92 percent of the total number of lactating cows and are typically divided into eight groups.
Group size is determined by the size of the parlor and milking frequency. Observations on commercial dairies indicate a group should be milked in 60 minutes when milking 2X per day, 40 minutes when milking 3X per day and 30 minutes when milking 4X per day. This will constrain the amount of time cows are being kept away from feed and water to no more than two hours per day.
Within the eight groups of healthy lactating cows, individual cows are assigned to pens based on nutritional requirements, reproductive status and social factors. First, heifers respond favorably when grouped separately from older cows. Heifers have lower dry matter intakes (DMI) and greater growth requirements as compared to older cattle. In addition, mixing heifers with older cattle increases social pressure, resulting in less than optimal heifer performance.
Heifers should be kept in separate groups and divided based on reproductive status. Heifers could be grouped as open, not breeding, breeding and pregnant. This increases labor efficiency during breeding by concentrating all breeding activities to one pen. The remaining healthy lactating cows are allotted to groups by reproductive status and nutritional needs. Nutritional requirements for these groups vary and, as above, concentrating breeding activities maximizes labor efficiency.
One disadvantage to the above grouping scheme is the need to move cows from pen to pen. Movement of cattle increases labor requirements and disrupts the social order in a pen. Usually, three to four days are required to reestablish social order when cattle move to a new pen. The result is reduced feed intakes and lost milk production.
As a result, some producers have chosen to freshen cows as a group and maintain the group throughout lactation. Rather than moving the cows to correct diet or management area, this strategy brings the diet and management to the cow. The difficulty in this system is calving enough cows to fill a pen in less than 30 days.
In addition to the healthy lactating cows, some lactating cows will have special requirements. Separating fresh, sick, lame or slow-milking cows increases parlor and treatment labor efficiency, as well as reducing stress on the cattle.
Fresh cows will account for 4 percent of the healthy herd size, assuming the number of calvings annually is 115 percent of lactating cows. The fresh cows should be housed in a loose housing pen for 10 days.
Provisions must be made to segregate nonsalable milk. Careful attention to intake, milk production, health and cow comfort is necessary for cattle in this pen to prosper. The sick pen should handle 2 percent of the healthy lactating cows. Removal of the sick cattle from the healthy pens is necessary for efficient treatment, to prevent antibiotic contamination of milk, and increase cow comfort.
It is recommended the fresh and sick pens be loose housing with sand bedding in order to maximize cow comfort. Lame and slow-milking cows often are housed in the same pen and located close to the milking parlor. Removing slow moving or slow-milking cows from the other pens will increase parlor efficiency 8 to 10 percent. Lame and slow-milking cows will be about 2 percent of the healthy lactating cows and can be housed in freestalls.
On large dairies, nonlactating cattle should be divided into five groups defined as maternity, overconditioned dry cows, underconditioned dry cows, close-up dry cows and close-up heifers. Nutritional needs of these groups vary greatly and grouping of these heifers and cows according to nutritional requirements is critical to minimize metabolic problems associated with calving.
Ideally, cows calve in individual maternity pens. Close attention to close-up pens allows cows that are just beginning the calving process to be moved to the calving pens. Cows normally stay in the maternity pen less than 24 hours. The number of maternity pens needed is approximately equal to .33 percent of the total milking cows.
These plans do not include a quarantine area. True quarantine pens should be located away from this facility. If a true quarantine period were desired, springing heifers would need to be received at another facility at least one month prior to moving to this facility. In general, this is not the typical practice. Thus, the overflow pen will generally be utilized as the receiving pen for replacement heifers.
Site evaluation and selection
Preliminary site evaluation includes state or federal guidelines. Generally, land for crop production and manure application is rented or owned by a partner. Immediate and future environmental consideration would suggest 1 to 2 cows per acre of land would be required for manure application. This is based on phosphorus being the limiting nutrient, which likely becomes the standard in most areas. Currently, many use 5 to 10 cows per acre, but potential exists for excessive nutrients (primarily phosphorus and potassium) being applied to the land unless a crop consultant is used to monitor nutrient accommodation.
Other factors such as waterways, separation distances, neighbors, etc. may limit the area where manure can be applied. The facilities, buildings, feed center and waste management system will require approximately 1 acre per 75 to 100 cows. Initial site evaluation must consider the availability of three-phase electricity, water accessibility and sewer (manure storage and handling). If any one of these four items appears cost-prohibitive or not feasible to obtain, another site should be considered.
Martin notes other factors to consider include:
•Access by milk and feed trucks
•Separation distance from other buildings for good natural ventilation
•Prevailing wind direction (for its effects on ventilation and potential odor problems)
•Distance from neighbors and town surrounding land use
•Distance from all surface water (rivers, streams, lakes and wetlands)
•Soil type (effects waste management)
•Depth to water table and bedrock
•Drainage and slope
•Availability and quality of water supply
•Availability of cropland for utilization of manure nutrients
The layout of the complete dairy operation will be determined based on plans for:
•Freestall barns (numbers of groups, stall layout, etc.)
•Treatment and maternity facilities
•Dry cow, close-up dry cow and fresh cow facilities
•Calf and heifer housing (if needed)
•Manure and milking center wastewater handling and storage
•Collection and storage of runoff from outside lots
•Storage facilities for corn silage, haylage, dry hay, commodity feeds, etc.
Complete plans for waste handling, storage and land application must be developed by a consulting engineering and dairy design team. All regulatory agencies must approve the plans before any construction begins (health department, milk inspector, designated manure regulatory agency, local government, etc.). PD
References omitted due to space but are available upon request.
—From Kansas State University Extension website
J.F. Smith, M.J. Brouk and M.J. Meyer, Department of Animal Sciences and Industry, Kansas State University; J.P. Harner, Department of Biological and Agricultural Engineering, Kansas State University; D.V. Armstrong, Department of Animal Sciences, University of Arizona; M.J. Gamroth, Department of Animal Sciences, Oregon State University; Gene Boomer, Greg Bethard and Dana Putnam, Monsanto Dairy Business