Pork producers in the United States who are looking for lower coststructures for raising pigs have shown a great deal of interest in hoopbarns or hooped shelters as facilities for housing gestating swine. Hoopbarns can be used successfully for gestation and breeding as a workablealternative to gestation crates, but producers need to be aware of theadvantages and disadvantages of this type of housing.

A number of manufacturers are offering these units for sale, and research-based information is available to help producers decide if a hoop barn is agood investment. To help producers and designers resolve some of the issuesinvolved in using a hoop barn, this publication summarizes information aboutdesigning and using hoop barns. It discusses some of the managementtechniques that hoop barns require, and it presents economic factors that canbe used to analyze design layouts and construction alternatives.

Authors:

Jay D. Harmon

Professor, Agricultural and Biosystems Engineering, Iowa State University

Mark S. Honeyman

Professor, Animal Science, Iowa State University

James B. Kliebenstein

Professor, Agricultural Economics, Iowa State University

Tom Richard

Associate Professor, Agricultural and Biosystems Engineering, Penn State University

Joseph M. Zulovich

Extension Assistant Professor, Ag Engineer, Agricultural and Biological Engineering, University of Missouri

Hoop Barns for Gestating Swine

MW PS

Agricultural Engineers Digest A E D 44 09/

09/2004 / Reprint 08/2008Published by: MidWest Plan Service. Revised Edition

Contents

Overview 2Basic Questions 2When to Consider Hoop Barns 2Designing and Erecting Hoop Barns 3Using engineered or non-engineered

hoop barns 3Design and construction details 4Foundations 5Frames 6Covers 6Snow and wind loading 7Environment and Ventilation 7Ventilation openings 7Endwall ventilation 7Effects of temperature on breeding stock 8Cooling 9Hoop Management 9Managing the physical structure 9Managing group-housed

gestating sows 9Managing breeding of group-

housed sows 10Managing the feeding area 10Daily feeding 10Interval feeding 11Feeding Systems 11Feeding stalls 11Self-feeders 12Floor feeding 12Bedding 12Manure Handling 13Removing solid manure 13Storing solid manure 14Applying solid manure 14Example Layouts 14Layout with feeding stalls 14Layout with self-feeders 14Layout with floor feeding 17Cost Analysis 17Research Analysis 18Summary 18References and Resources 20Reviewers 20

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OverviewA hoop barn is a Quonset™-shaped structure with

sidewalls 4 to 6 feet high made of treated wood postsand wood sides or concrete sidewalls. Tubular steelarches fastened to the tops or sides of the posts form ahooped roof, which is covered with a UV-resistant poly-vinyl tarp. When used for swine housing, most hoopbarns have concrete or earthen floors. Buildings withearthen floors have a concrete slab for a feeding andwatering area. In a gestation housing application, thefloor, except for the feeding and watering area, is deepbedded and cleaned one or more times per year.

Figure 1 shows a hoop barn used for gestatingfemales, and Figure 2 shows the common componentsof a hoop barn.

Hoop barns are naturally ventilated and aresited to take advantage of prevailing winds. Inthe Midwest, most buildings are oriented in a north-south direction.

Basic QuestionsMost of the previously available information about

using hoop barns for swine housing came from farmerexperiences and comparisons in magazines and newsarticles. Recent research performed in Canada and atIowa State University has added to what is known aboutusing hoop barns for gestation housing. Producersthinking about building any type of swine housing needto answer questions like the following to determine ifbuilding the structure is a good idea.

• Does the design of the building makepossible and convenient the use of optimalor preferred management practices?

• Is the design conducive to providing for theanimals’ needs during all seasons?

• Is the design structurally sound, and does itmeet common tests of reliability andlongevity?

• Is the design cost effective?• How well does the structure fit in with the

operation’s overall production goals?• Is the site suitable for the structure?• Is equipment to operate the structure

available?• Are environmental permits necessary?

When to Consider Hoop BarnsHoop barns appear to be most beneficial for producers

who satisfy one or more of the following criteria:• Want facilities with versatility to match a

rapidly changing swine industry.• Need a short-term structure that could be

removed after use or that is adaptable forother uses.

• Want to keep fixed costs low.Figure 1. Hoop barn for gestating swine.

Figure 2. Common components of hoop barns.

Treated boards

Hoop frame

Polyvinyl tarp

Treated tongue and groove 2 lumber"

Treated posts

Ratchet tie-downs(See figure 9 for detail)

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• Have limited capital.• Are not interested in accepting the

additional financial risk associated with alarge capital investment.

• Want to improve the housing of thebreeding herd that is currently on outsidelots.

• Need an isolation area for new sows or gilts.• Prefer to handle solid manure and have the

capability to do so.• Have the equipment and land resources to

harvest crop residue for bedding andreapplication.

• Prefer a system of production that is lessautomated and requires different husbandryskills than those needed in confinementbuildings.

• Believe pigs should be reared in anenvironment with bedding.

• Need a structure built quickly.• May want to qualify for certain niche

market requirements and premiums.

Table 1 shows a comparison of various sowgestation facilities. Hoop barns for gestating sowsare a good alternative for people considering movingsows from outside lots or Cargill type floor units toa facility that has a more manageable thermalenvironment, that provides better runoff control,and that allows better feed usage and sowobservation while allowing many of the sows’natural behaviors.

If the producer is seeking a facility that hasalternative uses, the case for investing in hoop barnsbecomes even stronger. Finally, if this producer’sgoals in pork production include the use of aproduction system that requires a lower capitalinvestment and if equipment for harvesting cropresidue and for handling solid manure is alreadyavailable, the logic of investing in a hoop barn ismore compelling.

Designing and Erecting Hoop BarnsProducers who decide to build a hoop barn need

to treat the construction project as they would anyconstruction project involving a new structure.Aspects to consider include what type of structureto build; site selection; and proper access to thebuilding for moving feed, bedding, and pigs.Producers thinking about building a hoop barn alsoshould consider the building’s usefulness within anexisting operation, its proximity to neighbors, theavailability of services and utilities, and thepossibility of using the structure in conjunction withexisting buildings.

Using engineered or non-engineeredhoop barns

Although hoop barns do not have an extensivehistory in the United States, Canadian farms havebeen using hoops for several years. In both the U.S.and Canada, many models have proven to last 10years or more if they are well maintained. Factorsinfluencing the life include the use of strong, tear-resistant tarps, corrosion resistant structural mem-bers, and sidewalls that are well maintained andnot abused.

One factor producers should consider is whetherto purchase an engineered or a non-engineeredstructure. When a hoop barn is engineered, aqualified designer (typically a registered engineer)has analyzed how each component of the structurewill interact with the other components of thestructure. A qualified designer has analyzed howthe loads applied to the roof (or tarp) will affect thedesign of the tubular frame and how the tubularframe will transfer forces vertically and horizontallyto the sidewall frame.

In addition, the designer has considered theforces the animals themselves will exert against thesidewalls and has designed the sidewalls towithstand the outward push of the frame and pigs.In an engineered building, the foundation has been

Table 1. Comparison of gestation areas.

Gestation Thermal Comfort Runoff Feed Housing Sow NaturalArea Control Control Management Investment Management Sow Behaviors

Dirt Lots/pasture Very Poor Very Difficult Very Difficult Very Low Very Difficult MaximalCargill Floor Unit Poor Difficult Difficult Medium Difficult ModerateHoop Good Easy Moderately Easy Medium Moderately Easy ModerateConfinement Very Good Easy Easy High Easy Minimal

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specified to withstand the loads transferred fromthe wall. Structures that are engineered have beendesigned to meet snow and wind loads for thegeographic area in which they are to be erected. Animportant point for producers to consider is thatengineered structures are more easily insuredbecause they are assured to meet weather designconditions. Insurance agents should be consultedabout insurability issues before any building ispurchased and constructed.

An engineered structure typically will includethe frame, tarp, sidewall materials, and materialsto anchor the building to the foundation. Warrantiesfor engineered structures range from 10 to 15 yearson materials and workmanship. Engineeredstructures often are more insurable than non-engineered structures, and engineered structuresoften cost less to insure.

Some hoop barns on the market have not beenengineered. Hoop barn dealers often sell a roofingsystem instead of a complete structure. Included inmost packages are the tubular frame, tarp, andmaterial to attach the tarp to the sidewalls. Thebuyer must purchase the wood posts and tongue andgroove boards to construct the sidewalls. Many times,non-engineered structures will have less than a three-year warranty on products and workmanship. Non-engineered structures may have little if any resalevalue after five years.

Producers must ask themselves questions likethe following when considering the purchase of a hoopbarn:

• How long do I want the structure to last?• Do I want to have the opportunity to resell

the structure in the future?• Will the extra cost of buying an engineered

structure outweigh the savings of buyinga less expensive, non-engineered structure?

• How does having an engineered structureaffect my ability to get insurance on thestructure?

Design and construction detailsHoop barns are naturally ventilated and are sited

to take advantage of the summer prevailing winds. Formuch of the Midwest, the building is oriented in a north-south direction to take advantage of the summerprevailing winds from the south. Prevailing summerwinds should blow through the building.

Concrete slabs are used with some feedingsystems. For slabs around waterers, slope the concreteaway from the bedded area so that spilled water willnot enter the bedded area. A slope of 1 to 2% (1/8 to 1/4 inch drop per foot) is sufficient.

The remaining deep-bedded area of the struc-ture can have either an earthen or concrete floor,with many producers preferring concrete for easeof cleanout. A complete concrete floor will makecleaning much easier because it prevents the prob-lem of sows digging into the underlying soil. A con-crete floor also tends to reduce bedding usage insummer because pigs cannot dig to reach cooler soil.In some states, regulations require concrete floorsto prevent nutrients from leaching into the under-lying soil and groundwater.

If the bedding area is to be concreted, the soilshould be compacted to prevent differential settling.A 5-inch slab with woven wire placed in the center(vertically) of the slab should be sufficient for mostapplications. The concrete floor should have astrength of 4,000 psi. Thicken the edges of the slab,particularly at the end where vehicles will drive intothe bedding area for cleaning. Place the concrete flat.

When building multiple hoop barns, provide atleast 10 feet of space between buildings. This willallow space for equipment to travel between buildingsand allow for snow removal and moisture drainage.Grade soil to take rain away from the structure.

Both wood and concrete sidewalls are relativelycommon, with increasing interest in using concrete.For wood sidewalls, the steel frames are fastenedto the tops or sides of the posts that support theoutside wall. Commonly, pressure treated 6 x 6'sare used as posts. Pressure treated tongue andgroove 2 x 6’s are used on the animal side of theposts to form the sidewalls of the animal space.

Either poured or precast concrete walls can beused for hoop barns. Either must be designed tosupport the design loads caused by the hoops.Properly engineered hoop frames connected toprecast concrete walls, similar to those used inbunker silos, can be a good choice in that thestructures can be moved if necessary. Concrete forthe sidewalls is more durable than wood but maybe more expensive, and may be colder for theanimals to lie against. Pouring concrete sidewallswould make the hoop barn a more permanentstructure. If concrete sidewalls are used, they mustbe designed to accommodate the fasteningrequirements of the selected brand of hoop barn.

Typically the sidewalls are 4 to 6 feet high. Six-foot sidewalls are recommended to prevent pigs fromdamaging the tarp when a great deal of bedding hasaccumulated. Figure 3 shows the inside details of atypical hoop barn.

Livestock panels or gates form the north andsouth endwalls at animal level. In the winter, thesegates are covered with sheets of galvanized steel,

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recycled plastic, or plywood to reduce drafts. In allinstances, the north wall can be closed relativelytightly to reduce winter winds using commerciallyavailable tarps or plywood sheeting. Some producersalso partially close the south end in cold weatherusing commercially available tarp kits, especiallyin northern climates of the United States. In thesummer, both the north and south ends are totallyopen, with the steel, plastic, or plywood panelsremoved from the end gating to increase air flow inthe pig zone.

Endwall construction should include posts thatwill be close enough to fasten the end gates adequately,but far enough apart to allow room for feeding andmanure handling equipment. If the posts extend tothe height of the hoops, do not fasten the posts to theend hoop. Hoops can deform during winds and willrub against the posts. Rubbing against the posts maydamage the tarp material. Commercially available endtarps will reduce the potential for damage. Figures 4,5, and 6 show typical endwall configurations forvarious weather conditions.

FoundationsThe foundations of hoop frames must be able to

transfer the loads applied to the frame to the earth.Wind applies horizontal and uplift loads to thesidewall frame, while snow, rain, and the weight ofthe frame apply vertical loads downward to thesidewalls. The foundation anchors the building tothe earth and must resist corrosion from contactwith manure, moisture, and the soil.

The most common method of anchoring the frameto the foundation is to build a post frame wall withthe posts extended below the frost level and then

Figure 4. End open during mild weather.

In the Midwest, both ends would most likely be open in mildweather.

Figure 6. End closed during cold weather.

This is a typical configuration for the north end of a hoopstructure in the Midwest during harsh winter weather.

Figure 5. End partially open during mild winter weather.

During harsh winter weather, this end would be fullyclosed.

Figure 3. Inside view of a typical hoop barn.

Plywood has been added above the structural wall toprevent the pigs from damaging the tarp and to direct coldincoming air upwards.

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construct a 4- to 6-foot high wall along the sides ofthe frame. Some manufacturers also offer steel trussposts to which the arches are attached. In eithercase, the pipe frame is attached to the tops or sidesof the posts. Posts must be set properly. If posts areset improperly, they can move out of plumb and affectthe structural integrity of the building. Posts shouldbe set below the frost line and on top of concretefootings. The soil around the posts must be tampedproperly. Do not set posts in areas that have a highwater table. Precast concrete sidewalls can be placedon a crushed rock layer or on concrete. The weightmust be adequate for the hoop barn to resist winduplift forces. Follow engineered designs from the hoopbarn supplier.

FramesHoop frames are constructed primarily from

2- to 3-inch O.D. (Outside Diameter) round tubularsteel to form a roof truss system. Steel purlinsconnect the trusses to each other to act as a unit,Figure 7. The thickness of the tubing used in framesranges from 16 to 12 gauge. (The lower the gaugenumber, the thicker the tubing.) Frame sizes dependon building width and frame spacing. Somenarrower hoops use tubing only, without forming atruss.

Frames are spaced at various widths from 6 to16 feet, depending on the design. These framessupport the roof and sidewall construction of thebuilding. See Figure 8 for an illustration of how thetarp is fastened to the sidewall and frame.Galvanized steel tubing 1-3/8 inch O.D. is used forpurlins and bracing to span and brace between theframes along the length of the building.

While frame widths for single span structuresusually range from 18 to 36 feet, many hoop barnsfor gestation swine span 40 feet or more withengineered truss arches to allow more flexibility inlayout. Some manufacturers span from 40 feet towell over 100 feet with engineered truss arches suchas the one shown in Figure 7. Truss arches also areused when high snow or wind loads are a concern, orif a lower roof height is desired. Wider hoop barnsshould have an open ridge located in the middle ofthe arch to facilitate good moisture removal.

Because of the corrosive nature of an animalhousing environment, high quality galvanizing iscrucial. Some manufacturers use hot dippedgalvanizing, which produces excellent results. Othertypes of galvanizing, however, may not be suitable foruse in animal environments. Check the quality andamount of galvanizing in the frame tubing anddetermine what type of warranty is available from

the supplier. Aluminum frames are an option withsome suppliers. Aluminum frames used with theappropriate fasteners should experience less corrosionthan steel in the conditions that exist in typical swinehousing.

CoversTarp coverings for hoop barns come with various

options, but evaluating what type of tarp to getshould be an integral part of the overall design anddecision-making process. Generally, tarps are madeof woven polyethylene fabric that is produced fromlow-density polyethylene extruded over high-densitywoven polyethylene. Due to the woven nature of thetarps, punctures do not tend to run. When puncturesoccur, they may be patched with a kit the companyprovides. The better tarps are those that have beentreated with ultra-violet (UV) stabilizers and a fireresistant substance to provide safety and longevity.Producers should consult their insurance companyon which treatments are required for insurability.

Tarps generally come in different weights,which may include 10.0-, 12.5-, and 14.9-ouncefabric. Many colors are available, including clearand opaque fabric. Fabrics that have a whiteunderside or are white and allow some lightthrough tend to make a building brighter and makethe animals easier to see. Clear fabrics are not agood choice because they allow a high degree ofsolar penetration, which may overheat animals.Pro-rated warranties for tarps are generally 10 to15 years. Rub points, such as purlin connectionsand end wall connections, tend to wear first. It isbest to minimize such rub points.

Figure 7. An engineered truss arch used to support

a wider span and when snow or wind loads are a

concern.

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At night a hoop barn loses heat to the coldsurroundings and the cold, clear, black sky. This coolsthe air in the structure, lowering its moisture-holdingcapacity substantially and causing relative humidityto rise. The result is cold, damp air and, most likely,excessive condensation on the underside of the tarp.

To reduce risks to animal health from poor airquality, hoop barns must be well ventilated, and theventilation must be well managed. A hoop barn mustbe managed just as any cold, naturally ventilatedstructure. Do not close the structure too tightly. Donot attempt to manage the structure as a warm barn;it is primarily a shelter. Properly managed, airtemperature in the hoop barn 4 to 6 feet above thebedding pack is often within 10F of the outside airtemperature.

Because wind is a major force in ventilating anynaturally ventilated structure, orient hoop barns tointercept the prevailing summer wind through theend opening. Do not construct hoop barns wherebuildings, trees, or other large obstructions block theprevailing summer winds. For most structures, theminimum separation distance from obstructions tothe end of the building is 75 feet.

Ventilation openingsNatural ventilation uses openings at different

heights to achieve ventilation in the winter. Buildinga structure with an open ridge will allow the moist airthat builds up to escape through the opening at thetop of the structure. For sow housing, because of therelatively low stocking density, a ridge is unnecessaryunless the structure gets excessively long. In thesebuildings, ventilation air enters through a continuousspace along the sidewall where the tarp is attachedand exits through the ends of the hoop, depending onwind direction. Figure 8 shows a 3- to 6-inch gapbetween the top of the wall and where the tarp overlaysthe wall; this gap serves as a continuous air openingfor ventilation.

Because openings are not adjusted, the hoop actsmostly as a wind and snow shelter and does not maintaina set temperature. Problems with air quality occur mostoften when hoop barns are closed too tightly.

Endwall ventilationHoop barns without ridge vents are difficult to

ventilate naturally if they are too long. Typically, ahoop barn longer than 100 feet, without ridge vents,and filled with animals will present ventilationproblems. Longer hoop barns can be used in high windareas. In all areas, hoop barns rely on endwall openingsto aid airflow through the structure. The ends are openmost of the year. Figure 9 shows an example of how

Snow and wind loadingIn general, the structure must be able to meet

snow and wind load requirements. Structures thatdo not meet snow and wind load requirements riskfailure and may not be insurable.

The snow load design should be similar to whatother agricultural building loads are for the area inwhich the building is being constructed. The effectof snow on the structure can vary. Snow may slideoff the roof, or the snow may accumulate and putadditional weight on the tarp and hoops. Generally,snow loads are not seen as a big concern becausethe curvature of the structure minimizes snowbuildup.

Wind loads also should be calculated as theywould be for other agricultural structures in the area.Additionally, uplift of the frame under wind loadsneeds to be considered in the design of the frameand the foundation anchoring. In some designs,diagonal bracing of the sidewalls from the endwallsand along the roof line should be incorporated.Outside guy wires can be important to keep the framefrom racking or deforming out of plumb. Frames thathave shifted off center are likely to be loadedunevenly and are subject to failure. Some reports ofwind damage have indicated that hoops sometimesdeform without failing.

Environment and VentilationPerhaps the top priorities for hoop barns used as

swine housing are the issue of animal environmentand the related issue of proper ventilation. Realisticexpectations for these structures are that they reduceexposure to wind and snow in winter and sun andrain in summer. Hoop barns are cold barns and shouldbe managed as such. Although the bedded-manurepack generates considerable heat and enhances animalcomfort for pigs in the winter, hoops require specialmanagement for year-round operations.

The primary goal of hoop barns is to protect theanimals from the weather. In the summer, thebuilding should provide shade and allow crossventilation by wind. In the winter, the housing shouldallow for moisture removal and draft control. In thewinter, a cold barn with dry bedding allows the pigsto create a suitable, comfortable microenvironmentin the bedding.

A natural tendency of producers using hoop barnsis to restrict ventilation to keep warmed air inside thestructure. However, when the hoop barn is being usedto house animals, restricting ventilation traps themoisture the animals produce along with the warmair. This creates a situation that can be damaging tothe pigs’ health.

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the gap between the top of the endwall and the frameand tarp acts to aid natural ventilation when the endsare closed.

Where such devices as hovers or wind baffles ongating are used to reduce drafts, the draft preventiondevices must still allow ventilation and moistureremoval to occur.

Effects of temperature on breeding stock

The production efficiency of breeding animals maybe affected by the environment in which they arehoused. Cold temperatures generally do not effect thereproduction efficiency of boars and sows unless boars

suffer scrotal frostbite or the feeding levels of gestatingsows are too low to maintain fetal pig developmentand meet body maintenance requirements. Sows andboars housed in colder conditions will requireadditional feed because they will use more energy tomaintain homeothermic conditions. A commonrecommendation is 0.8 pounds of additional feed forevery 10 degrees colder than 50 degrees, Table 2.

Hoop barns are designed to serve as coldhousing. Heat is not added to the structure, andthe indoor air temperature will generally remain5 to 10 degrees above the outdoor temperature.During winter the north end of the structure willgenerally remain closed. Air comes in through slotson either side of the frame walls, rises to the top ofthe hoop, and moves out the ends. Sows remaincomfortable in cold conditions because they canmodify their environment with the use of beddingand huddling with other animals. A source of highquality dry bedding is essential to the success of thisstructure.

Hot weather is much more harmful for breedingefficiency. Boars that are exposed to an elevatedeffective temperature will experience poor semenquality for a 6- to 8-week period that begins 2 to 3 weeksafter exposure. Sows are more heat tolerant exceptduring the first 2 to 3 weeks of gestation and duringthe last 2 weeks before farrowing. Litter size and weightmay be severely affected during these periods.

During summer months both ends of the hoopshould be left open to allow air flow through thestructure. Boars and sows should be maintainedwith effective temperatures below a daily averageof 80 F and below 86 F as a maximum. To achievethis, less bedding is used, and interval sprayersystems may be necessary.

Table 2. Additional feed requirements for gestation sows fed

corn-soy diets in cold weather.

Additional feed usage of 0.8 pounds per 10 degrees fortemperatures colder than 50 degrees.Results typical for midwest winters and feed intake.

Additional Feed Required

Month (lbs per day) (lbs per month)

November — —

December 0.50 to 1.00 15 to 30

January 0.75 to 1.50 20 to 45

February 0.50 to 1.00 15 to 30

March 0.00 to 0.50 0 to 15

April — —

Additional Feed: 50 to 120 pounds per sow per year

Figure 9. Hoop frame connected to endwall.

A gap at the top serves as a continuous air opening forventilation.

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Figure 8. Tarp properly fastened to frame and sidewall.

Note the space between the wall and the tarp; this spaceacts as a continuous air inlet for ventilation.

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CoolingIn confinement facilities with liquid manure

systems, cooling can be accomplished using athermostat and cycle timer with a sprinkler systemto wet the pigs and then allow them to dry. Allowingthe water to evaporate between cycles draws heatfrom the pigs’ bodies as the water evaporates offtheir skin. This evaporation helps to cool the pigs.Any excess water ends up in the manure collectionsystem.

With hoop barns, a similar system can work,but there are a few obstacles. Hoop barns are notalways equipped with electricity so the use of athermostat and cycle timer may not be practical.Excess water will go into the bedding rather thaninto a manure collection system thereby creating awet place for the pigs to lie, even when temperaturescool off in the evening.

Work in Australia with bedded finishingsystems has shown that it is best to wet most of thepigs at the same time. This spreads the water acrossa large area, including the bedded area, and helpsto avoid excessive water on the bedding. Sprinklerscan be attached to the roof trusses to cover a portionof the barn. This same system can be used for sows.With this type of arrangement, leave some areas ofthe hoop barn, including the feeding area, un-wettedto give animals a choice of environments. Pigs mayhave a tendency to lie on bare concrete to remaincool, but wetting the concrete feeding area willencourage the pigs to lie in the feeding area more,making it difficult for the animals to have access tofeed. In operations using feeding stalls, the wettingdevice may be located over the stalls. Allow 10 to 12square feet per pig when determining the area tobe sprinkled.

Wetting of the pigs should be done using a cycletimer to allow evaporation of water from the pig’ssurface to provide the cooling effect. Sprinklersshould put out large droplets instead of a mist. Largedroplets are designed to cool the pigs; misters aredesigned to cool the air immediately above the pig.Also, misters depend in part on airflow and losesome effectiveness when the relative humidity inthe pig zone where the misters are spraying is at orabove 75%.

Timers should be set to operate anytime thetemperature exceeds 80-84F, and they should turnsprinklers on for 1 or 2 minutes out of a 10- to 20-minute period. Specific settings will vary withclimate, pig size, humidity, temperature, wind, andwater pressure, but the critical issue is wetting thepigs and then allowing them to dry and cool as thewater evaporates. Producers will have to experiment

with several settings to find the right one for aspecific location. The goal is to wet all the sows in 1to 2 minutes and then allow them to dry. Just asthey become dry, the water should turn on again.

If electricity is not available, sprinklers will haveto be managed manually, or there may be optionsusing solar or battery-operated controllers. In eithercase, the producer must observe the pigs frequently,adjust the system accordingly, and avoid allowingpuddles to form in the bedding. Careful managementis necessary to prevent problems with wet beddingand inadequate drying time, but pigs digging holesin the bedding pack has not been a problem whenwetting devices are managed properly.

Hoop ManagementEquipment selection, material handling, and

animal handling techniques are important factors thataffect both the longevity of the structure and sowcomfort. Hoop barns have four main managementissues:

• Managing the physical structure.• Managing group-housed gestating sows.• Managing breeding of group-housed sows.• Managing the feeding area.

Managing the physical structure

Structure management issues include:• Managing the structure as a cold barn.• Providing frost-free or no-freeze waterers.• Handling rainfall runoff in an

environmentally satisfactory way.• Providing lights if heat checking is

performed after dark.• Providing one watering space for every 30

to 40 sows.• Providing an extra nipple waterers in the

summer if necessary.• Developing a maintenance schedule that

includes checking the entire structure every12 months, and checking the tarp for tearsand tautness every 6 months.

• Prevention of the floor/ground freezing inthe hoop between groups.

Managing group-housed gestating sows

To minimize stress and maximize performance,group-housed sows need to be handled differentlythan sows housed individually. Bred sows shouldbe housed separately from bred gilts. Bred sows orgilts should not be mixed into a group before 28 daysof gestation, preferably not before 42 days ofgestation. Studies have shown that litter size andfarrowing rate are lower when sows are mixed

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during the first week after mating compared to 28days after mating. When sows must be introducedto a large group, add at least 10% of the total groupsize to minimize fighting. Housing groups of sowswith a mature boar during the first week can helpminimize sow fighting as the boar is recognized asthe dominant animal. The best method to managesows is to maintain a group that does not increaseor decrease in numbers. If sows or gilts need to beadded to a group, a method of sorting and remixinggestating sows must be employed.

Sows in groups should be as uniform in size aspossible. Uniformly sized sows are especiallyimportant when sows are group fed daily becausethere is less chance of a dominant sow getting toomuch feed. Sows must be fed in a way that minimizescompetition for feed and manages individual sow feedintake. Interval feeding, trickle feeding, or providinglocking feeding stalls can eliminate the possibility ofthe dominant sow getting too much feed. Intervalfeeding should be used with caution because it canlead to lower reproductive efficiency.

Introducing replacement gilts to a group is achallenge. First parity gilts are best kept separatethrough their first gestation, if possible. They canthen be commingled after weaning of their first litter.This allows the pregnant gilts to be developedseparately from older sows. Weaning is a good timeto introduce new sows to the group. Keeping a staticgroup as much as possible is the preferredmanagement tactic. Static means managing thegroup as a batch. That is, the group is bred, farrowed,and weaned at the same time. Dynamic groups,groups of sows where sows are added and removedfrequently, must continually reestablish their socialorder, leading to more fighting and possible injury.

Managing breeding of group-housed sowsHoop barns can be used as breeding facilities.

Boar pens, breeding areas, and weaned sow pens allcan be included in the gestation hoop barn (Figure19) or in a separate breeding hoop (Figure 20).Producers may want to build a small heated room touse as an AI lab, although such a room is not required.When designing the layout for breeding facilities,separate the boar pens from the weaned sow pens toprevent the sows from becoming refractory to theboars. If the sows are artificially inseminated infeeding stalls, it may be helpful to pen a boar in thealley immediately in front of the sows duringinsemination to improve estrus (heat) detection andto speed the insemination process. Design alleys andboar penning to facilitate boar movement for heatdetection and rechecking of bred sows.

Although the hoop barn is not heated, thebreeding area can be dry and draft free during thewinter. Summer cooling is critical for boars andsows. Provide maximum airflow during hot periods,and sprinkle cool sows and boars. See page 8 foradditional details. Boars are particularly subject toheat stress, and boar fertility and libido can bediminished if boars are not kept cool.

The example layout in Figure 20 uses three hoopbarns. The two large barns are for sows, and themiddle, smaller barn is for boars. Boars are movedto the sow barn for heat detection. Sows to beinseminated can be sorted out and walked to the boarbarn for breeding in a breeding alley adjacent to theboar pens. Alternatively, the sows can be inseminatedin the pens or alley in the sow barn. This alternativemethod reduces sow movement, which can be difficultduring estrus when the sows lock up.

Managing the feeding areaThe feeding area is the most expensive compo-

nent of the hoop barn. Many times during planningthe layout, producers decide how to make the bestuse of the feeding area. While it is important to makethe feeding area economical, the most importantissue of the feeding area is how to make this best fitthe producer’s sow management goals.

Some of the questions a producer needs to askwhen deciding on the layout of the feed system are

• How much do I want to control feed intake?• How often do I want to feed sows?• How often do I need to observe the sows?• How much can I afford to spend on the

feeding area and on a feeding system?• How much labor do I want to use for

feeding sows?

Deciding the feeding frequency is a good start toanswering these questions. The two options in feedingfrequency are to feed sows daily or at intervals.

Daily feeding

Daily feeding is the most common feeding planand allows for the most flexibility when makingchoices about the feeding system. Daily feedingencourages daily sow observation. Feeding stalls,self-feeders, or floor feeding can be used for dailyfeeding. If self-feeders are used, provide one feederspace for every five to ten sows in a group. If feedingstalls are used, provide one stall per sow in a group.If floor feeding is used, provide enough space to allowall the sows in a group to eat at the same time.

Daily feeding requires more labor and planningif used with a shared feeding area. In a shared

11

feeding area arrangement, sows fed ad lib may notbe able to consume all the feed they need beforebeing moved back into their pen to allow the nextsow group to be rotated into the feed area. Sowgroups that have to wait while others are fed maybecome very loud and agitated.

Interval feeding

An interval feeding program allows sows to eatad lib for a certain duration of time every two orthree days. A fenced feeding pen with self-feedersis required. Because sows haven’t eaten for at leasta couple of days, at least one feeding space is neededfor each sow fed, although extra spaces may bebeneficial.

In interval feeding, sows are turned into a selffeeding area where they eat until they are full, at whichtime they are removed. This method uses feedingequipment for several groups, thereby spreading thecost over more animals. Enough feed should beavailable so all sows eat their fill, with the dominantsows eating first and the others eating later.

The negatives of interval feeding are that themanager has little control over the individual sow’sfeed intake. Sow aggression may occur around thefeeders. Avoid using interval feeding with bred giltsbecause they may not consume enough feed toprovide the necessary energy needed to maintainpregnancy and their own growth between breedingand farrowing. Also avoid interval feeding duringearly stages of gestation because this is a time thatsows need extra energy for maintenance, growth orrecondition, and pregnancy. Sows or gilts will havelower reproductive efficiency if their energy levelsare not maintained.

Feeding SystemsSelecting a feeding system is a major decision

with group-housed sows. Three major choices areavailable:

• Feeding stalls.• Self-feeders.• Floor feeding.

Regardless of which systems us used, the feedingarea in a hoop barn usually is a concrete pad elevated12 to 18 inches above the bedded area to keep thebedding off the feeding platform, Figure 10. The padshould slope away from the bedded area. Many timesthe waterer is located on the concrete pad. Theconcrete pad should slope away from the waterer anddrain away from the bedded area. The concrete padshould extend at least 10 feet around feeders andwaterers. If the feeding area is located on only one

side of the structure, it is preferable to locate thefeeding area on the west side of the structure. Becauseof afternoon sun and wind patterns, the west side isoften hotter than the east side. During summer, thecooler east side of the hoop is where the sows willspend most of their time.

Feeding stallsFeeding stalls are an excellent choice when

housing sows in hoops, Figure 11. Individual, lockablefeeding stalls take up considerable space (about 12square feet per stall). New stalls cost $50 to $100each and can require more labor than other feedingsystems. Sows should enter the stalls from the back.

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Figure 10. Concrete step to separate the elevated

feeding area from the bedded area.

Figure 11. Feeding stalls with rear locking gates.

12

Self-feedersTo feed group-housed sows, self-feeders are a

lower cost option than feeding stalls. Because self-feeders are an ad lib feeding system, they work wellwith interval feeding management. Self-feeders canbe easily incorporated into a shared feeding area.The main disadvantage of self-feeders is that theydo not allow individual sow management.

Self-feeders take up less overall space thanfeeding stalls, but at least an additional 10 feet ofspace are needed around the feeder to allow sows toeat comfortably and to allow sow movement. Thedisadvantage of self-feeders is that feeding sows ingroups can encourage aggression as well as createa disparity of feed intake.

Floor feedingFloor feeding is accomplished by dropping feed

on a concrete floor and allowing the sows to eat in afree-for-all manner. The disadvantage is that thedominant sows will tend to eat more than the timidsows. This can result in uneven conditioning. Theadvantage is that it is inexpensive because it requiresminimal equipment.

Feeding on the concrete pad is low labor (espe-cially with automated feed drops), can be relativelyinexpensive, and uses a moderate amount of space.The manager has no control over individual sow feedintake. Sow fighting and aggression are encouragedbecause the larger, aggressive sows get more feed.Using feed drops can be expensive, while feeding withbuckets is inexpensive but more labor intensive.Feeding is on a daily basis. Individual sow manage-ment is difficult, but feeding according to smallergroups of similarly sized sows can help make thissystem successful.

BeddingBedding is one of the keys to successful produc-

tion in hoop barns, especially in the winter. The pro-ducer must determine how many bales of crop residueare required to provide bedding and then harvest ina timely manner to provide quality bedding. Withearthen floors, enough bedding must be provided tokeep the soil under the bedding pack relatively dry.Sows will establish certain dunging areas through-out the structure. Many times, winter groups willsleep in the far back and along wooden sidewalls anddung in the space between the bedding area and theconcrete slab used for feeding and watering. Addi-tional bedding will be required to prevent the dung-ing area from becoming sloppy.

Several materials have been used successfullyfor bedding although most experiences have been

Stalls also should have front gates that can allowthe sow to exit the stall and be moved to the farrowinghouse or breeding pen. The key advantage of feedingstalls is that they allow individual management(feeding, vaccination, AI, etc.) of group-housed sows.Provide at least one feeding stall per sow in a group.Each stall should have a lockable rear gate. Vulvabiting can be a problem when not enough stalls areavailable or locking exit gates are not provided.

Individual feeding uses feeding stalls in whichanimals may be confined during feeding. This allows eachanimal to get an individualized rate of feed to maintainuniform animal conditioning. The disadvantage is thecost and space used, and the increased labor to close andopen the crates at the appropriate time. Automating feeddelivery and gate opening can reduce labor costs but willadd to facility costs. Because sows enter various feedingstalls at feeding time, an automated feed delivery systemwill give each sow the same amount of feed. Extra feedmust be added by hand for thin or young sows.

One variation of the feeding stall is the electronicfeeder. Electronic feeders are an automated way tofeed and manage sows individually, Figure 12. A singleelectronic feeder can feed a single group of 50 to 60sows. The electronic feeders use a relatively smallamount of space. Typically, electronic feeders arelocated in a single pen and are not used in a sharedfeeding area. Electronic feeders allow increasedmanagement because they keep track of sows that donot eat. However, an electronic feeder requires a majorcapital investment and ongoing maintenance andmanagement. Electrical power surges and lightningcan cause problems with the computer that managesthe feeding system.

Figure 12. An electronic feeder.

13

with baled corn stalks. Table 3 lists other productsthat could be used, along with the approximateamount of bedding needed.

If a 1,200 pound bale of cornstalks costs $10 to$20 for baling, transportation, and storage, the costof bedding per sow space with three gestation turnsper year would be between $17 and $50. Besidescorn stalks, some producers have used soybeanstubble bales successfully. However, soybean balestend to be dustier than corn stalks. Other producersuse barley straw, wheat straw, oat straw, prairiehay, and wood shavings. Bedding used shouldbe free of molds to prevent problems during sowgestation. Wood products should be used withcaution. Shavings and sawdust need to go througha heat cycle to avoid the transmission of aviantuberculosis to the sows.

While the selection of bedding is based mostlyon what is readily available, many other concernsshould enter into the decision. These concerns varyfrom region to region and include the following:

Soil conservation: In regions where residuecover is required on highly erodible lands, theharvesting of corn or bean stalks may not be a goodoption. The producer must consider how muchresidue can be removed per acre while stillcomplying with existing conservation plans.

Custom baling: Custom baling of stalks maycost between $10 and $15 per ton. Additional costsare incurred in transporting bales. On-farmbaling, while requiring less out-of-pocket expense,is not a low-cost option. Additionally, stalk balingresults in more wear on round balers than doesnormal hay baling.

Bedding availability: During years in whicha wet fall or early snow prevents stalks from beingbaled in a timely manner, they may become lessavailable and more costly. A situation of this typecould require a shift in priorities from doing all ofthe grain harvesting first to a system of harvestingand baling stalks. A variety of bedding sources canminimize the risk on not having enough beddingdue to inclement weather in the fall.

Bedding storage: Bedding baled in the fall andused before the spring generally does not deteriorateif stored outside. However, if stored into the springand summer, bedding must be protected to preventreduction in quality. Bales that will be used duringspring and summer should be stored under coveron a well drained area. Bales stored outdoors willlose bedding quality, thereby increasing costs.Depending on bedding quality, most producers tendto use between 2,000 and 3,000 pounds of corn stalkbedding per sow space in the hoop barn. This means

Table 3. Estimated amount of bedding needed for gestation

sows in a hoop barn.

Values based on estimated differences of absorbency.

Average

Bedding Usage

Material (lbs per sow turn)

Corn stalks 670 to 1,000

Corn cobs 800 to 1,200

Barley straw (long) 800 to 1,200

Oat straw (long) 600 to 900

Wheat straw (long) 750 to 1,130

Sawdust (hardwood) 1,120 to 1,680

Sawdust (pine) 670 to 1,000

Wood shavings (hardwood) 1,120 to 1,680

Wood shavings (pine) 840 to 1,250

that for each 100 head of gestation capacity in hoops,approximately 200 bales of corn stalks would berequired each year.

Manure HandlingBefore considering a hoop barn, one must

carefully plan on how to handle the bedded pack.The proper equipment to remove the manureresulting from the bedded pack must be available.If direct application to a field is not possible, thenspace to stockpile the manure must be available.

Knowing the nutrient content of manure isessential for those who have a manure managementplan. Because of the drier bedding from hoop barns,the manure will have a higher-carbon/lower-nitrogen status than manure from facilities withsemisolid or liquid manure systems. Manure with ahigh-carbon/low-nitrogen status may lead tonitrogen immobilization and crop stress if appliedduring or immediately prior to the growing season.

Removing solid manure

The manure/bedding mixture removed from thehoop barn is either directly spread on fields or storedfor later use. Typically, there are few custom haulersavailable that will handle solid manure. If this is thecase, a manure spreader, loader, and tractor mustbe available for on-farm usage. Corn stalks are oftenused in the Midwest for bedding. Corn stalk beddingis not easily handled due to the potential forwrapping on manure spreader beaters. An ordinaryskid-steer loader will probably not be sufficient totear apart the pack for loading.

Most producers agree on 7 to 9 hours of totallabor to clean a moderate sized hoop barn and spread

14

the material on nearby crop land. The best equipmentto remove the bedding pack is a mechanical, front-wheel assist tractor with a grapple fork attachmenton the front end loader. One producer reports usinga chisel plow to disrupt the bedding pack beforecleaning.

Storing solid manure

If manure is applied directly to the fields,storage requirements are minimal, but if solidmanure is not applied directly to a field aftercleaning then designing a space to safely stockpilethe manure is necessary. Knowing the amount ofmanure to be stockpiled is necessary to properlydesign the storage area.

As it comes directly out of the hoop barn, thehigh degree of variability in the bedded pack makesit difficult to predict manure nutrient contributionsto crop fertilization needs. Composting is likely tooccur if the manure is stored for any length of timeand will provide volume reduction of one-third toone-half and nutrient stabilization prior to fieldapplication. Such composting will occur withminimal management if the material is piled inwindrows about 6 feet high and 12 feet wide.

Bedding from gestating sows in hoops tends tobe much drier than that from finishing pigs, andmoisture is likely to limit the extent of compostingunless additional manure or water is added to thepiles. Mixing the material to achieve a higher degreeof uniformity would improve this situation, andmixing currently occurs to some degree if the beddedpack is piled for storage or composting prior to fieldapplication. Additional mixing, as would occurduring turned windrow composting, may offer abenefit with this material. Contact your localCooperative Extension service for recommendationson composting manure.

There is some concern about nitrogen leachingfrom storage, especially during high rainfall. In somestates, the environmental control agencies areconcerned about runoff and will inspect areas ofstockpiled manure. Storing manure on a concrete padcan be an effective management tool that will providea solid base to make manure removal easier and canbe designed to safely control runoff from the area.Contact state environmental control agencies todetermine proper procedures for stockpiling manure.

Applying solid manure

In some places in the Midwest, much of theagricultural land base is highly erodible. As part oftheir conservation plan, many producers havesigned an agreement with the federal government

to maintain 30% residue coverage after planting.Using large amounts of residue in hoop barns hasraised the following concerns:

• The properties of the manure vary greatlythroughout the structure. Some areas willhave a high concentration of manure whileothers will be mostly bedding; therefore,the fertilizer value of the manure andresidue mixture can not be estimatedaccurately and credited for nutrientcontent.

• If they are not chopped first, corn stalksspread on fields may interfere withminimum tillage operations.

• If the farming operation plans on using no-till, will the producer be able to land-applythe residue in a thin enough and uniformenough pattern with existing manurespreaders to minimize planting problems?

• Substantial organic matter will be returned tothe cropland, but will a high carbon-to-nitrogen (C:N) ratio prevent the nitrogen frombeing fully available for crop use the first yearfollowing land application?

Example LayoutsHoops used for gestation and breeding generally

are designed to provide at least 24 square feet ofbedded area per sow. Pen layout usually depends onthe feeding system and group size. The number ofsows per pen or group is a factor of farrowing room/house capacity and conception rate. Pens should beat least 15 feet wide to minimize control by aggressivesows and allow timid sows to pass freely.

Layout with feeding stallsThe gestation layout in Figure 13 is designed for

two groups of 44 sows. Feeding stalls are placed on araised concrete pad at the south end of the hoop. Thefeeding area is designed so that only one group ofsows is allowed to eat at a time. This design minimizesthe equipment cost by allowing feeding stalls to beshared. Shared feeding stall usage on a daily feedingsystem may require some added labor.

Feeding stalls in Figures 14 and 15 are locatedon a concrete pad on which feed is dropped forfeeding. Feeding stalls are located on the west sideof the structure.

Layout with self-feedersFigures 16, 17, and 18 show facilities designed

for interval feeding with self-feeders. Figure 16shows two groups that share an inside feeding areaat the south end of the building. Figure 17 shows

15

Figure 15. Group-housed sows with individual

feeding stalls.

Figure 13. Feeding stalls on the south end of a structure.

Figure 14. Feeding stalls on the west side of a structure.

Group of 20 sowsGroup of 20 sows

10' t

o 12

'

84'30

'42'

14' t

o 16

'

Alley

7' Feeding stalls

Waterer

Group of 44 sows

Waterer

Gates

22 Stalls per side 56'

40'14

'6'

6'

20'

8'

7' Feeding stalls

7' Feeding stalls

Waterer

Panel

104'

Group of 44 sows

four groups of 25 that share a feeding area in thecenter of the building. This design minimizes thearea devoted to feeding, but animals will be exposedto different conditions depending on where in thefacility they are housed. Added labor may berequired since more than one group may need to befed in a day. Feeding one group at a time will createa noisy environment due to the other groups beingagitated as they wait.

The layout in Figure 18 was designed fortwo groups of 36 sows with an outside feeding area.This allows more of a uniform environment.Waterers are typically located on the walls, but oneshared waterer can be located between the pens nearthe swing gates.

16

Figure 18. Outside interval feeding.

60 to 72' '

20'

40'

16' Minimum to 20',typical

Waterer

Waterer

Group of 36 sows

Outside pad

Group of 36 sows

N

Figure 16. Interval feeding for two groups

Group of 36 sows

Self feeder

20'

100'

40'

20'35'

Waterer

Swing gateGroup of 36 sows

N

Figure 17. Interval feeding for four groups.

Group of 25 sows

Self feederConcrete raised 16" Gate

90'20'35'

Waterer

Group of 25 sows Group of 25 sows

Group of 25 sows

40'

20'

N

17

No Feeding Stalls Elevated Feeding Stalls

Facility Investment (3 gestations) (2 gestations) (3 gestations) (2 gestations) Your Estimate

Building Cost $10,000 $10,000 $18,000 $18,000 Feeders-Waterers $1,500 $1,500 $1,500 $1,500Total $11,500 $11,500 $19,500 $19,500

Capacity (sows) 60 60 60 60Investment per Sow Capacity $192 $192 $325 325Gestated Litters per Sow Space per Year 3 2 3 2Investment per Gestated Litter $64 $96 $108 $163

Cost per Gestated Litter

Facility Cost (16.5%) $10.54 $15.81 $17.88 $26.81Bedding Cost $8.38 $8.38 $8.38 $8.38Feed ($0.06 per pound) $33.00 $33.00 $31.50 $31.50Cleaning $0.53 $0.53 $0.53 $0.53Total per Gestation * $52.45 $57.72 $58.29 $67.22

* Note: Does not include all costs.

Table 4. Swine gestation cost comparison. (Partial costs)

Layout with floor feedingThis system is simple and probably one of the

most inexpensive designs. However, individualconditioning of sows is sacrificed, and the groups ofsows will be exposed to different environments.Feeding stalls are located along one wall with dropfeeders, similar to Figure 14.

Cost AnalysisTable 4 shows a cost analysis comparing hoop

barns with differing levels of use. Costs varydepending on location and availability of materials,so you are encouraged to fill in the Your Estimatecolumn with values that reflect your operation. Thetable presents information for a hoop barn that isconsidered a basic unit without feeding stalls, andfor another that has feeding stalls. They are alsoevaluated for two versus three groups per year.Initial investment cost is $11,500 for the basic unitper year and $19,500 for the unit with feeding stalls.

Fixed costs are as follows: Depreciation = 10%,interest = 5%, insurance and taxes = 1.5 %, which leadsto a fixed cost of 16.5%. The annual interest rate is10% or 5% on average for the life of the investment.Depreciation at 10% is based on the premise that thehoop barn will last 10 years. Given that using hoopsfor animal housing is a relatively new practice,information on life expectancy is not complete.However, it appears that they will last at least 10 years.

Bedding requirements for 3 gestation turns peryear using corn stalks is about 1 ton per sow spaceper year. For Table 4, the bedding is valued at $15per 1,200 pound corn stalk bale. Assuming 670

pounds of corn stalks are used per sow turn, thecost per sow per turn is $8.38.

On average, buildings are cleaned after every 2gestation turns. An operation using 3 gestationturns per year would clean the buildings an averageof 1.5 times per year. Each cleaning will take about7 to 9 hours or about one day. With a cleaning timeof 8 hours and a labor cost of $8.00 per hour, thecleaning cost for 3 gestation turns would be $96 peryear. The cleaning cost would be $32 per group or$0.53 per sow per gestation period.

Using 5 pounds of feed per day for 110 days, feedconsumption would be 550 pounds per sow pergestation period. Using a feed cost of $0.06 perpound, total feed cost would be $33 per sow pergestation period. Feeding stalls can allow moreprecise feeding thereby reducing feed cost by about4.5%. Feed cost per sow per gestation period wouldbe $31.50 using feeding stalls.

Initial facility cost is higher for the system thathas feeding stalls and an elevated platform. Notethat cost per gestation (including those costs in Table4) is affected by the level of use of the facility. Asystem with feeding stalls with three gestationgroups per year costs less than the basic system usedfor two gestation groups per year. It is important torealize that the costs in Table 4 do not include allcosts. For example, labor for sow feeding and care,veterinary medicine, utilities, and repairs, are notincluded. Systems with feeding stalls and otherenhancements increase the ease of working with thesows, providing shots, using artificial insemination,and tracking sick sows. Information of this type

18

along with the amount of labor or differences in laborbetween the two systems is not known. These trade-offs cannot be easily evaluated at this time and willbe related to management styles.

Research AnalysisFigure 19 illustrates the layout for the breeding

and gestation hoop barn at the Iowa State UniversityArmstrong Farm, Lewis, Iowa. This system, while ithas worked well, is relatively expensive due to a largeamount of concrete, low animal density, and highequipment cost. However, it fills a niche because it isdesigned for a small herd and includes boar andbreeding pens. Constructing a crated gestation barnfor this size herd would be economically impractical.The environment within the hoop is generally notconsistent from end-to-end, so animals in differentpens will experience different environments. Inaddition to the research done in this barn, Iowa StateUniversity also has conducted longer-term researchwith gestating sows in hoop barns in southwest Iowa.Conclusions in this document are drawn from bothresearch activities.

The research at Iowa State comparing theperformance of group-housed gestating sows inbedded hoop barns (similar to that shown in Figure14 with groups of 35 sows) to that of gestating sowsin individual gestation crates has led to the followingconclusions:

• Well managed groups of gestating sows inbedded hoop barns with individual feedingstalls can achieve performance comparableto that of individually crated sows.

• Feeding stalls are an excellent way tomanage sows individually within the groupand to minimize fighting over feed. Thestalls also provide a safe place for sows thatare the target of aggression during non-feeding times or for sows that want to lie onconcrete during hot conditions.

• Housing a boar adjacent to the sow pens hasmade detection of recycling sows easy inhoop barns.

• Soundness problems were fewer for sowshoused in bedded hoop barns than for sowshoused on concrete slats.

• The hoop barn requires cleanout about twotimes a year.

• The watering area needs to be constructedto drain to the outside of the hoop barn.

• Sprinklers over the concrete feeding areaeven with feeding stalls are very effectivein cooling gestating sows in bedded hoopbarns.

SummaryFor diversified, moderate-sized swine producers,

hoop barns offer some additional considerations. Thestructures are versatile and could be used foralternative purposes, for example, hay, machinery,or grain storage. The hoop barns can be constructedwith on-farm labor. The versatility, productionflexibility, and low capital costs may result inreduced financial risk. The quality of the workenvironment is generally good, with no liquidmanure and a large volume of naturally-ventilated

Figure 19. University research and demonstration layout for a small herd with space for boars,

breeding, and bedding.

7' Feeding stalls

Weighscale

Waterer Feed alley

Boarpen

Boarpen

Boarpen

Boarpen

Beddingstorage

Concrete raised 16"above bedded area

Weaned sow group14 head

Gilt pool8 head

Gestating sows14 head

14' 4"25' 4"3'

25' 4"

8'

68'

19'

12'

8'10'

4'

40'

Optional pens

Waterer

N

19

air inside the building. Manure can be stockpiledfor spreading at appropriate times.

However, the added bedding increases the volumeof solid manure and requires a different type of manuremanagement than liquid manure. Some bedding mayneed to be protected from adverse weather for use latein the year. Low cost, high quality bedding must be ahigh priority for the system. Also, it is unclear whetherpathogens will build up in the soil floor over longperiods of use.

Following is a summary of questions to beexamined when considering hoop barns.

• How often does the tarp need to bereplaced?

• What types of bedding can be used?• Will storage be needed for bedding?• Will there be disease and parasite buildup

in soil under the deep bedded area?• Will heat from the decomposing manure

pack cause problems in hot humid weather?• Will manure and residue harvesting

equipment need to be purchased as anadded expense?

The full impact of new swine housing alternativessuch as hoop barns needs to be evaluated for short-and long-term effects. Producers considering a hoopbarn need to evaluate initial costs and operating costsfor each alternative. They also need to gather as muchinformation as possible about animal performancein different types of housing.

Among the major issues that a producer mustconsider are the following:

• Hoop barns have lower fixed costs and higheroperating costs (for example: bedding, labor,feed usage) than totally enclosed housing.

• Hoop barns are versatile and can be used forother applications, such as machinery storage, ifnot used to house pigs.

• If the tarp covering needs to be replacedbefore 10 years, tarp replacement costs mustbe added to cost calculations.

• Because hoop barns have a lower initial cost,producers can test their capability in swineproduction without a large investment.

• Producers who want to erect more than onehoop barn for a swine operation may find that

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Figure 20. Hoop system using two barns for sows and one barn for boars.

20

...And Justice for All.MidWest Plan Service publications are available to allpotential clientele without regard to race, color, sex, ornational origin. Anyone who feels discriminated againstshould send a complaint within 180 days to the secre-tary of Agriculture, Washington, DC 20250. We are anequal opportunity employer.

Copyright © 2004, MidWest Plan Service,Iowa State University,Ames, Iowa 50011-3080 (515-294-4337)

Printed onRecycled Paper

the volume of crop residue for soilconservation will become a limiting factor.

• Producers wishing to improve their situationof earthen lots or Cargill style lots withshelters have a low investment opportunity.

• Feeding configuration has importantimplications on cost and sow conditioning.

• Group management can affect sowproductivity.

The financial information presented in Table 4of this publication suggests that for a particularapplication, a hoop barn can be a competitivealternative building for pork production. However,producers should analyze their costs and comparealternatives. Given similar costs, other factors maytip the building decision to a hoop barn or a totallyenclosed building.

Personal preference and perceived benefits of onestyle over another may sway a producer to choosethe housing type that is more appropriate for aspecific situation. For example, a producer who wantsto expand quickly may find a hoop barn to be thebest alternative, while another producer mightconclude that the longer history and known attributesof totally enclosed housing are more appealing.

References and ResourcesAdditional information about the topics discussed inthis publication is available in the following sources:

AED-30. Preservative Treated Wood for Farm andHome, 1989. MidWest Plan Service.

MWPS-33. Natural Ventilating Systems for LivestockHousing, first edition, 1989. MidWest Plan Service.

MWPS-35. Farm and Home Concrete Handbook, 1989.MidWest Plan Service.

Connor, M.L., D.L. Fulawka and L. Onischuk. 1997.Alternative low-cost group housing for pregnant sows.Livestock Environment V, Proceedings of the FifthInternational Symposium. ASAE. St. Joseph, MI.

Connor, M. L. Group housing of sows: is it an option?,1996. Manitoba Swine Seminar, University ofManitoba, Winnipeg. 10:111-115.

Connor, M. L., L. Onisichuk, Q. Zhang, R. J. Parker,and J. I. Elliot. Alternative housing with Canadian

Biotech shelters and a review of some Europeanconcepts, 1994. Can. Soc. Ag. Eng. Paper 94-232,Saskatoon, Saskatchewan.

Edwards, W. and D. Smith. 2004 Iowa Farm CustomRate Survey. 2004. Iowa State University, Ames, IA.

Halverson, M.K. and M.S. Honeyman. 1997. Humane,sustainable feeder pig production: Transferringtechnology developed in Sweden to Midwestern hogfarms. Livestock Environment V, Proceedings ofthe Fifth International Symposium. ASAE.St. Joseph, MI.

Harmon, J. and H. Xin. Thermal Performance of a HoopStructure for Finishing Swine, ASL-R1392. 1996Swine Research Report, Iowa State University,Ames, IA.

Honeyman, M. Iowa State University sow loose-housinggestation model. 1995 Swine Research Report, IowaState University Pub. AS-633, Ames, IA.

Honeyman, M., J. Harmon, D. Lay, T. Richard.Gestating Sows in Deep-bedded Hoop Structures,ASL-R1496. 1997 Swine Research Report, IowaState University, Ames, IA.

ReviewersMichael Brugger, Facilities Administration,

The Ohio State UniversityTed Funk, Assistant Professor and Extension

Ag Engineer, University of IllinoisJim Lindley, Associate Professor of Ag Engineering,

North Dakota State University (retired)James Murphy, Professor and Extension Ag Engineer,

Kansas State UniversitySteve Pohl, Extension Ag Engineer, South Dakota

State UniversityRandall Reeder, Associate Professor and Extension

Ag Engineer, The Ohio State UniversityTim Safranski, State Swine Breeding Specialist,

University of MissouriThomas Scherer, Extension Ag Engineer, North

Dakota State UniversityThomas Socha, Livestock Swine Specialist, North

Dakota State UniversityLaVerne Stetson, Agricultural Engineer USDA-ARS,

University of Nebraska (retired)Brian Strobel, Extension Associate Livestock Systems,

The Ohio State University