Chapter 8 Site selection.
After completing the study of this chapter, you should be able to
* list and describe key issues affecting dairy site selection.
* identify the advantages and disadvantages of retrofitting an existing dairy.
* identify the advantages and disadvantages of building a new dairy.
* evaluate existing or potential dairy sites using the site-selection criteria.
gravity-flow manure handling system
nonpoint pollution source
point pollution source
Site selection is one of the most important aspects of the dairy planning process. A good site will increase cow comfort and labor efficiency, and support the long-term growth of the operation. Each site has its own size and orientation requirements and limitations. You should research the different options available, their limitations, and their implications for the long-term growth of your business.
The principles of site selection are similar for producers planning a new dairy and those transitioning from an existing dairy. Producers transitioning from an existing dairy must decide whether to build a new facility at a different site or to add facilities to an existing site. This choice is critical and should be made before any additional resources are deployed at the old site.
Proper site selection should conform to the current and long-term goals of the operator, and consider land required for facilities, crop production, and manure disposal. No matter what size of operation a producer is considering, facility site selection should support potential future growth. For example, if a producer currently milks 60 cows in a tie-stall barn with a pipeline milker and wishes to milk 120 cows housed in freestalls with a parlor capable of milking 60 cows per hour, the selected site and building arrangement should support the number of cows that the parlor can accommodate. In this case, site selection and building placement should not consider just the 120-cow herd size, but the potential herd of 390 if milking 3X (60 cph X 6.5 hour shift) or 630 if 2X (60 cph X 10.5 hour shift). This thought process is difficult for many producers considering their first expansion, but experience has shown that once a dairyman switches to freestall-parlor type systems, successive expansions come quickly. Even if the producer has no long-term plans to expand further, the next owner may, and it would be foolish to exclude the possibility.
Herd-Size Implications of Expansion Alternatives
It is often difficult for producers to choose the correct herd size for the initial and subsequent phases of an expansion. Starting with a smaller initial herd size can be an advantage in that (1) fewer additional employees must be hired, allowing the owner more time to adjust to an expanded management role; (2) less initial investment is required; and (3) less land and equipment are needed for feed procurement and manure management. The most difficult problem associated with small expansions is the cost to milk each cow. Normally the cost of housing and of the milk cow herself do not vary by the size of operation, but since parlor costs come in fixed increments, the associated cost per cow to harvest milk can vary substantially based on the amount of time the parlor is used. A recent summary of the cost of new milking parlors in Wisconsin (Frank, 2002) shows an average cost of about $18,000 per milk stall. (This value includes the cost of new equipment, and the building to house the parlor, equipment, offices, and holding area.) Producers tend to build double-8 or larger parlors that offer better use of milking labor than smaller parlors, and must decide if the herd size being considered can support the cost of such a new parlor (double-8, 16 stalls at $18,000 per stall, or about $288,000). Since most producers who build new milking parlors milk three times per day, each milk stall has the capacity to milk about 30 cows (6.5 hour shift X 4.6 turns per hour). Table 8-1 shows that the cost to harvest milk decreases by almost $2 per cwt ($1.67 versus $3.63) when a parlor is used at its full potential. Producers considering moving to a parlor system should remember that their competition, who fully utilize their parlors, have about $600 investment per cow ($18,000 per 30). To put this in perspective, if a producer wants to milk 120 cows and have an equivalent investment per cow, then a low-cost parlor option totaling about $72,000 should be considered (120 cows X $600).
Site Selection Factors
Proper location selection can maximize cow comfort, save on construction costs, and reserve space for future growth. Do not select a site because the land in question has no other good uses. A team approach to site selection, which allows many ideas and points of view to be incorporated, often results in the best final decision. Remember to consider safety and security when selecting a site; calves housed in unlit areas near infrequently used roads may disappear at night.
Local weather patterns (temperature and humidity ranges, rainfall amounts and timings, and winter storm frequency and severity) will govern the type of facility that should be constructed on a site.
To determine the area required, the operator should sketch an overview of the proposed dairy, showing the location of all barns, the milking facility, feed storage, and manure storage. Existing buildings, roads, streams, property lines, utility lines, drainage ways, wells, neighbors, and any other sensitive areas should also be shown. Barn dimensions can be calculated based on the type of freestall barn and the number of stalls desired. Adequate space should be provided so that no structure interferes with the airflow of other structures. Large freestall barns normally must be separated by about 100 feet.
Manure storage should be calculated considering expected herd size, milk production level, and any additional manure system requirements. Water from flush systems and sand from sand-based freestalls can increase the storage requirements and, obviously, the manure pit size. Milk production levels have increased dramatically in the past few years, causing many manure-storage sizing recommendations to underestimate actual requirements. If the storage is to be emptied once per year, a minimum of 12,000 gallons per cow per year should be expected. After the sketch with dimensions is created, stake out the area to ensure that the site is appropriate.
No matter what size of dairy is being planned, try to reserve space for additional barns, feed storage, and so on, in case the need for them ever arises.
Barn orientation must be considered if freestalls are to be placed on outside walls (six-row or four-row tail-to-tail designs). Cows often refuse to use freestalls if the hot summer sun intrudes into the building (Figure 8-1). Roof extensions can be added to help protect cows on the outside rows of stalls. The length of this eave extension should be about one third the height of the sidewall (i.e., a four-foot eave on a 12-foot sidewall). Wind, snow, and ice conditions on unshaded feed fences should be avoided during winter. Facing open-sided barns to the east or south to avoid the cold northern and western winter winds is recommended. Naturally ventilated facilities should be built far enough away from other buildings (Figure 8-2) and trees (Figure 8-3) to prevent them from obstructing air movement. Modern freestall barns are often separated by about 100 feet to avoid this problem. Placing a manure pit close to a freestall barn is not recommended, as manure smells may enter the barn.
[FIGURE 8-1 OMITTED]
[FIGURE 8-2 OMITTED]
[FIGURE 8-3 OMITTED]
Prevailing Wind Speed and Direction
Seasonal prevailing wind speeds and directions are important from a cow-cooling standpoint in warm weather and cow-sheltering standpoint in cold weather. Check local wind maps to determine the most prevalent direction of summer breezes. Place barns so that the largest area of the structure faces the prevailing summer wind to enhance the cooling effect. Choosing the best building orientation on a site sometimes can involve a trade-off between wind direction (to maximize cooling) and sun angle (to protect cows from the sun on an outside row of stalls). Remember that the breezes crossing the barn to cool the animals will also carry odors and flies away from the farm site. Be careful not to place a dairy such that these nuisances are aimed at your or a neighbor's home.
If possible, freestall barns should be built with a high site elevation to maximize the cooling effect of natural breezes blowing across the barn (Figure 8-4). "On a knoll, not in a hole," as the adage says. A site that provides a sufficient drop in elevation to support a gravity-flow manure handling system can result in decreased manure handling and lower equipment maintenance costs. Areas within a 100-year (or less) flood plain should be avoided.
Site Slope and Water Drainage
A site that is too flat or too hilly can add appreciably to the overall cost of a dairy. A slope of two- to six-percent will provide drainage without erosion. Good subsoil drainage will help prevent frost heave of foundations. The manure management system selected will influence the slope needed and the size of the manure storage facility needed. Flush systems and outside lots both require two- to three-percent slopes, which may influence the amount of soil that must be moved. A site on a high elevation is ideal if it does not require extensive rearrangement to provide sufficient space for current and future growth. A topographic survey, which shows the elevation, and the advice of local excavators can help you estimate the costs to prepare the site.
[FIGURE 8-4 OMITTED]
Dairies must control both nonpoint pollution sources (such as cropland) and point pollution sources (such as direct discharge of milkhouse waste to a stream). Pollutants include manure, milkhouse waste, silage leachate, sewage, fuel spills, and so on. The local topography and distance from surface water (such as rivers, streams, lakes, and wetlands) should be considered. Building and site selection should support the diversion of clean stormwater away from-and manure-contaminated water into--a proper containment structure. Groundwater samples should be taken to verify that no current problems exist. Check local setback requirements, and place buildings at a sufficient distance from wells and sewage systems to avoid any contamination of groundwater.
Proper site selection involves knowing what lies under the surface. A professional soil scientist can help you do the geological homework necessary to evaluate the appropriateness of the site. Soil borings should be taken to determine soil type; presence, type, and depth of rock formations; and depth of water table. Bedrock formations close to the surface can restrict installation of underground utilities and basement parlors, and may preclude use of earthen storages for water or waste.
Consider carefully the soil types of a potential site. Cropland should have good soil depth and nutrient holding capacity. Building sites require firm, stable subsoil with a low shrink-swell potential. Avoid sandy or porous soil types for building sites, since they have the potential for groundwater contamination. Lagoons and holding ponds require clay subsoil with low permeability.
Each potential site should be checked to ensure that the water supply can support the long-term needs of the dairy herd being considered. Both quality and quantity of water are important. It is common for a dairy to use 100 to 150 gallons of fresh water per cow per day. Water should be tested to ensure that the quality is adequate for dairy cattle consumption. Well-driller logs for the local area and short-term pump tests may be used to approximate the expected availability of water on a site, but you may want to install a pump, and pump at the expected demand rate for several days to ascertain that sufficient water reserves exist.
Determine how far the site is from access to electric and telephone utilities. Three-phase power, recommended for large dairies, can be expensive to bring to a new site.
A well-developed roadway is important to support the truck traffic associated with a large dairy. Time should be spent investigating local highway load restrictions. A state-maintained, hard-surfaced highway (with bridges permitting large trucks) should be easily accessible. Prompt snow removal is important. Avoid sites requiring excessive road construction and maintenance from the dairy to public roads.
Cropland Needs and Soil Nutrient Balance
A nutrient budget should be created to determine that sufficient land is available to maintain a nutrient balance (N-P-K) for the herd size being considered. Sufficient land should be under your control so that manure disposal will not cause nutrient buildup. In the Midwest, most feed delivered to the farm and manure returned to cropland have high moisture content, making them costly to haul. Current nitrogen-based standards often require close to two acres per cow for manure management. With phosphorous-based standards, which are likely to be implemented soon, this requirement could double in many areas. If land for manure application will not be owned, then it is advisable to establish long-term lease arrangements so that you have control over where, when, and how manure is applied.
Access to Cropland
Consider the distance and road access for hauling of feed and manure. If possible, select a site in the center of the cropland supporting the dairy.
Environmental regulatory agencies often require minimum distances between dairy facilities and neighboring homes. Check existing zoning restrictions for any potential site. Notifying neighbors early in the planning process (and keeping them informed of your plans) will often help smooth the permit process and avoid hostile public meetings. Correct facility design, site selection, and proper management can help avoid nuisance problems--odor and flies, and road contamination issues-that annoy neighbors. During calm, humid periods, topography can funnel odors down drainage ways to distant locations, especially to residences located in valleys. Consult topographical maps to avoid this situation. Try to avoid sites near current or potential housing developments. Consider a buffer zone or a tree windbreak to shield the operation. A separation of a mile or more is recommended between large livestock operations and neighbors.
Environmental Regulations and Permitting
Each producer should have the objective to build an environmentally friendly facility. It is important to identify early in the process all permits needed and the regulating agencies (such as health departments, milk inspectors, designated manure-regulating agencies, local governments, etc.) who grant them. Start early and try to develop a strong, friendly working relationship with all of the regulatory agencies that have jurisdiction over the site.
Expansion on an Existing Site
For existing producers who want to modernize their operation, the most difficult decision may be whether to use an existing site or go to a new location. Lenders often encourage building on a new site, because the resulting facility may be more easily marketed. Producers often favor expanding on an existing site to save money and to allow a slower, phased growth pattern. Both objectives have merit; the decision between them should be based on the financial resources available and the ability of the present site to support the long-term growth needs of the operation. If financial resources are limited, building near and utilizing existing facilities makes good sense. If this alternative is considered, make sure that the existing site and the existing facilities are thoroughly evaluated. Do not overestimate the value of existing silos, manure pits, sheds, and so on. Consider the overall effect on the site of a plan with and without each existing structure. Building on a site that has limited growth potential should be avoided if possible.
Building a New Dairy
Site selection is in some ways simpler for a new dairy, because the producer need not consider its effects on an existing operation. It is often more costly, however, because additional improvements (such as roads, wells, and utilities) must be brought to the site. Working within the aforementioned constraints and evaluating the cost-benefit relationship of different options should help in selecting the best site.
If an existing producer decides to build a new facility some distance from the current facility, the use of the old facility should be considered in site selection. If animals will be housed at the old site, feed storage, feed de livery, and animal movement implications should be considered. The size, age, and condition of existing storage should be considered when determining where additional storage should be built. Housing far-off dry cows at a second site requires weekly movement of animals. If close-up animals will also be housed on a second site, daily movement of animals is often needed. The labor requirement associated with moving animals and feed, plus the ability to properly care for maternity animals, should be factored into the site-selection decision.
Selecting the correct site for a dairy is the most fundamental--and often the most difficult-decision facing the dairy owner or manager. Producers have differing goals and circumstances, which add to the complexity of the decision. The ramifications can have a huge effect on cow comfort, labor efficiency, and the ability to support long-term growth. Organizing a team of experts who can help identify potential sites, site trade-offs, and growth strategies will often help improve the quality of the decision.
1. Describe a primary advantage and a primary disadvantage of phased expansion.
2. Identify five aspects of a site that must be evaluated when it is under consideration for dairy construction or expansion.
3. What is the purpose of a nutrient budget?
4. Identify the three ways in which a site's topography can affect its value.
5. Give two examples of an environmental regulatory agency.
6. Determine the site requirements of a 500-cow facility. What structures must be built, and how big should they be? What structural provisions must be made for feed storage, manure handling, hauling, and so forth? What site features would be ideal for this facility? Be sure to consider site size, water availability, utilities, access roads, and neighbors in your analysis. From your analysis, create a diagram of the site and a list of the facility's structural needs.
7. Imagine that the facility you described in your answer to the previous problem will be expanded to a 1,000-cow dairy operation over the next five years. Does the site you designed support this expansion? Modify your analysis, diagram, and facility list as necessary for the expanded size.
Frank, G. G. (2002). Milk harvesting costs. Low cost parlor options (pp. 1-3) [CD-ROM]. Madison: University of Wisconsin--Extension.
Martin, J. C., III. (1998, January 28-30). Siting large dairy facilities. In Fourth International Dairy Housing Conference, (pp. 29-36) St. Louis. St. Joseph, MI: American Society of Agricultural Engineers.
TABLE 8-1 Equipment and labor cost to harvest milk for parlors at differing levels of use. Full Use Half Use Quarter Use Cows milked per milk stall 30 15 7.5 Parlor investment per stall per cow $600 $1,200 $2,400 Repayment cost ($/cow/yr) * $116 $232 $463 Parlor labor cost ($/cow/yr) * $218 $233 $264 Total cost ($/cow/yr) $334 $465 $727 Cost per cwt to harvest milk $1.67 $2.33 $3.63 * Based on 9% interest and 7-year repayment, 20,000 lb annual milk production, and $10/hr labor.
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|Author:||Palmer, Roger W.|
|Date:||Jan 1, 2005|
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