HOUSING PIH-69
PURDUE UNIVERSITY. COOPERATIVE EXTENSION SERVICE.
WEST LAFAYETTE, INDIANA
Individual Mating Facilities for Swine
Authors
Wayne Singleton, Purdue University
Gerald R. Bodman, University of Nebraska
Don Levis, University of Nebraska
Reviewers
Joe D. Crenshaw, North Dakota State University
Rick D. Jones, University of Georgia
M. Ray McKinnie, North Carolina A.&T. State University
Tom Rhoades, Kingston, Illinois
A workable production schedule and an efficient mating pro-
gram are important to a successful pork production system. Each
producer has management circumstances to consider when planning a
breeding facility. One important consideration for all producers
is return on investment. The cost associated with an empty far-
rowing crate or finishing space must be recovered by the produc-
tion from those crates or spaces which are occupied. Buildings
must be utilized at or near capacity for maximum return on the
investment. A breeding facility must allow development of a
breeding and management program which consistently results in a
predictable farrowing rate and litter size that ensure an animal
for every available space. This level of performance will yield
maximum return on investment and an even flow of animals
throughout the production system.
When converting from a pen-mating to an individual mating
system, consider the benefits and limitations listed in Table 1
(individual mating also is referred to as hand mating). Indivi-
dual mating is considered an integral part of the breeding facil-
ities described in this fact sheet. The primary focus is the
breeding facility itself. However, a well-trained and motivated
employee is of equal importance. Consider an incentive program
for employees when farrowing rates consistently exceed a given
level during each breeding period.
Guidelines for Planning an
Individual Mating Facility
Newly constructed or remodeled facilities designed for indi-
vidual mating should be planned with the known benefits and limi-
tations in mind. Below are some factors to consider during the
planning process.
General Layout: Plan for animal comfort, worker safety and
labor efficiency. Design the system so one person can safely move
animals and assist with breeding. Use narrow alleyways to prevent
animals from turning around. Design gate latches which are easily
opened and closed. One design is shown in Figure 1. Provide ade-
quate lighting for observation of animals. Use a 2-tube, 40-watt
fluorescent fixture for each 200 square feet of floor space or
one 100-watt incandescent lamp for each 60 square feet. Provide a
convenient, well-lit area for recording mating information. A
chalkboard or clipboard is an excellent way to monitor boar use.
Develop a system which indicates current reproductive status of
females (weaned-not mated, mated once, mated twice, etc.). This
can be accomplished with paint stick marks or unique placement of
individual sow cards. Clothes pins attached to a wire over indi-
vidual crates to secure sow cards work well for some producers.
Production Schedules: Size the unit to accommodate animals
for the desired number of matings per breeding period (see PIH-
113, Calculating Swine Schedules). Also provide space for the
desired number of animals to be housed in the unit during the
pre- and post-breeding periods. Maintain gilts in this area for
2 to 4 weeks prior to breeding and also retain mated animals here
for 25 to 30 days post-breeding for their 21-day heat checks.
Plan additional space for short term housing of non-cyclic
females and early weaned sows. Generally, one should provide
space in the breeding area for females equal to 140% of the
desired number of farrowings for the period. Provide one boar
space for each desired pregnancy per period. For example, if the
production unit is designed for 12 farrowings per week, provide
12 boar spaces in the breeding facility.
Boar Facilities: House boars individually, either in crates
or pens. Individual housing increases longevity because it elim-
inates injuries resulting from fighting and mounting. Individual
housing also allows control of feed intake, and therefore, size
and condition of boars. Individually housed boars are usually
easier and safer to handle. Ejaculation frequency is controlled
because homosexual activity is eliminated. This results in a
more consistent and predictable level of boar fertility. Pens
should be approximately 40 to 50 sq ft and crates 7 ft long and
28 in wide (24 in for younger boars). Eight-foot-long crates may
be more appropriate for breeds or crosses which are larger and
longer when mature. Do not house unfamiliar boars side-by-side
in crates, because injuries may result from fighting. Crates
make efficient use of space but are not recommended unless boars
are used at least on a weekly basis. If not used weekly, boars
must be turned out of their crates for exercise.
Table 1. Benefits and limitations of individual mating in
environmentally controlled facilities.
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Benefits Limitations
_____________________________________________________________________
Known breeding dates enhance scheduling Requires dependable, well-
scheduling of facilities and labor. trained, and motivated labor.
A more detailed record system can be Specialized facilities are
utilized and reproductive success or required and may be costly
failure can be detected at an earlier to build and operate.
A specialized building which generally Specialized buildings are
accompanies an individual mating system not easily converted to other
can be designed to correct for a depres- uses.
-sion in reproductive rate associated
with extremes in weather conditions.
Boars can be penned and managed as
individuals, which extends their
useful lifetime.
The number of matings per boar can
be controlled.
Females can be double mated at the
correct time in relation to the onset
of estrus.
Selective matings are possible.
Land required for breeding lots can be
used for other purposes.
Farrowing rate based upon first estrus
services is generally increased as
compared to pen mating.
The spread in days within which a given
breeding group is mated is more easily
controlled.
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Sow Facilities: Research data are inconclusive as to the
best system for housing post-weaned sows. Crates provide a means
of controlling feed intake and reducing stress by preventing
fighting when sows are regrouped after weaning. However, each
sow must be moved from her crate once or twice daily for heat
detection. If sows are grouped in pens during the post-weaning
period provide 19 sq ft/sow and 16 sq ft/gilt. The number per pen
should be kept low at about 5 or 6/pen. When penned sows come
into heat, they have an opportunity to exhibit estrous behavior
(standing and mounting). Sows observed to be in standing estrus
can then be moved to the boar area for breeding. The remaining
sows can be moved to the boars for a more intense heat detection
program. Fighting among post-weaned sows kept in pens can be
reduced by delaying movement of sows from the farrowing house
until after nightfall and by placing a mature boar in their pen
for two days. Return the boar to his housing area prior to com-
mencement of heat detection and breeding.
Some breeding facilities are designed to accommodate
replacement gilts from the time of selection at 5 1/2 to 6 months
of age while others are designed to house them only for 1 to 3
weeks prior to mating. (See PIH-8, Managing Sows and Gilts for
Efficient Reproduction, and PIH-89, Managing the Gilt Pool).
Maintain a gilt pool large enough to guarantee the desired number
of bred gilts for each week. By adding gilts and selling those
in the pool that have not cycled after 25 to 30 days, a constant
number of females can be maintained without allowing non-cyclic
gilts to remain for long periods of time. There is little reduc-
tion in market price for such gilts if they are sold in the 250
to 275 lb weight range.
Temperature Requirement: Careful design of the ventilation
system is essential to meet the needs of animals throughout the
year, especially during extreme weather conditions. High tem-
peratures (above 80o to 85o F) may cause lowered semen quality in
boars, reduced farrowing rates and litter size, and increased
embryonic death loss in females. Heat stress also can cause
anestrus in females and decreased libido in boars. Therefore, in
most geographical regions, some method of cooling should be pro-
vided during the hot months of the year. Cooling can be accom-
plished with sprinklers coupled with air movement, ventilation
fans, evaporative coolers, earth tempered air or geothermal sys-
tems (see PIH-87, Cooling Swine).
Less is known about the influence of low temperatures, but
breeding units should be maintained at a minimum of 55o F to
reduce maintenance requirements of the animals and to eliminate
water freezing problems. During winter months, animal density in
the building may not be sufficient to generate adequate heat
while allowing sufficient ventilation to control moisture levels.
Therefore, some buildings may require supplemental heat for
animal comfort and replacement of heat removed by ventilation.
Whether or not swine require a given amount of light for
optimum reproduction is unknown. However, providing adequate
light at all times to enable observation of animals in an undis-
turbed state enhances animal management.
Breeding Area: For successful mating, provide boars and sows
with a slip-free surface which can be easily cleaned and kept
dry. In most building layouts the breeding area itself is con-
sidered a neutral zone and animals occupy this space only during
heat checking and mating. The flooring can be slotted, woven
wire, plastic-covered wire, solid concrete with a brushed or
grooved finish or a surface covered with rubber mats. If woven
wire is chosen, consider the larger diameter (5/16 in or 1/0
gauge) wire rolled flat on one side to improve traction.
Physical Arrangements and Management
Consider environmental conditions, production schedule,
management ability and personal preference when selecting a
building and floor plan. Floor plans described below incorporate
many of the suggested guidelines. Consult with Extension person-
nel and PIH-28 Sow Gestation and Boar Housing, for additional
arrangements. General breeding facility design criteria are out-
lined in Table 2.
Table 2. Basic design criteria for the breeding facility.
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o Pen space
Boars-50 sq ft
Sows-19 sq ft
Gilts-16 sq ft
o Crate size
Boars-young 24 in W x 46 in H x 7 ft L
-mature 28 in W x 48 in H x 8 ft L
Sows-24 in W x 42 in H x 7 ft L
Gilts-22 in W x 42 in H x 7 ft L
o Floor surface for breeding area
Slip resistant, cleanable
o Pen partitions
Breeding area and boars-4 ft H
Sows-36 in H
Use vertical rods with 4 in spacing
Clearance under gates and partitions-4 in
o Minimum floor slope-0.5% (1/16 in/ft)
o Minimum temperature for individually housed animals--55o F
o Alley width
Single animals-24 in to 28 in
Groups-36 in to 48 in
o Ventilation-minimum rates as listed in PIH-60 or MWPS-8
o Do not recess feed trough more than 2 in below floor level
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Design 1
The design shown in Figure 2 houses replacement gilts,
postweaned sows and boars. It was designed for animal comfort and
labor efficiency. Features of this arrangement are summarized in
Table 3.
Sows are generally weaned on Thursday and moved to the
breeding room. They are grouped in pens of four according to
size, condition and aggressiveness. Crates serve as free stalls
or rear gates can be closed if desired. Replacement gilts are
moved into the room 1 to 2 weeks prior to breeding. Estrus detec-
tion commences on the following Monday morning, with a majority
of the matings occurring on Tuesday and Wednesday.
Females in heat (being mounted by pen mates) are moved one
at a time to the breeding aisle and mated to the appropriate
boar. Remaining females are moved into the breeding aisle where
fence-line boar contact is provided. Those which react to the
back pressure test are mated and moved back into their pen. If
desired, the boar can be moved to the breeding aisle for the
final heat check. Swinging gates which divide the breeding area
allow for several matings to be in progress at the same time.
The number of sows which can be bred in an hour depends upon
the number of females in the group, how many are in estrus at a
given breeding time and the number of breeding pens. If four
breeding pens are provided, one person can heat check a group and
breed up to 15 or 20 females per hour.
Alternative Layouts for Design 1. A variety of ventilation,
manure removal and flooring systems can be incorporated into this
design according to individual situations. Crates could be sub-
stituted for pens for boar housing and the additional space used
for sow or gilt pens. In the post-weaning area, short (24 in)
stalls could be used instead of the full length (7 ft) .
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Table 3. Description of breeding facility Design 1.
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o Boar pens
5 ft W x 8 ft L x 4 ft H
Vertical pipe or bar pen partitions
7 ft concrete slats with 1 in spacing or 1/0 guage or 5/16 in
diameter woven wire
Recessed feed trough in back pen partition
Nipple waterer
o Breeding aisle
8 ft W (one swinging partition gate for every 2 or 3 boar pens)
Brushed finish, center crowned concrete or 1/0 guage woven wire floor
o Sow pens
13.5 ft x 8 ft pens with 4 crates, 2 ft W or 10 ft x 8 ft pens without
crates
Continuous concrete water/feed trough
Advantages: Disadvantages:
Convenient animal movement. Breeding activity in one pen can
Estrus can be observed without limit movement of boars.
removing sows from crates.
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Design 2
The design shown in Fig. 3 houses only boars and breeding
pens. All open and gestating females are located elsewhere. The
design details are listed in Table 4.
Generally, sows are weaned on Thursday and moved to facili-
ties adjacent to the breeding barn. Replacement gilts could be
housed in facilities adjacent to the weaned sows. Estrus detec-
tion commences on the following Monday morning by moving females
to a small pen adjacent to the breeding barn. Most of the matings
occur on Tuesday and Wednesday. Females are heat checked in one
of the four breeding pens. A female in heat will stand next to
the boar in the heat check boar stall. The heat check boar faces
the wall; therefore, the female usually remains in the breeding
pen while the center alley gate is open for the breeding boar to
enter. Boar movement is circular, i.e. boars enter the breeding
pens from the center alleyway and return to their stalls through
a narrow (28 in) alleyway by the wall. After the females have
been heat checked and (or) bred they are moved to a pen outside
the breeding barn. When four breeding pens are used at least 16
to 20 females can be bred per hour.
Alternative Layouts for Design 2. This style of breeding
facility can be used by any size swine operation. The number of
boar spaces (crates) is matched to the size of the breeding
group. Flexibility of the design allows for construction of a
breeding-gestation facility in phases. The first phase is to con-
struct a boar/breeding barn and keep all females in outdoor lots.
The second phase is to attach a sow house to the boar barn which
houses bred females indoors during the first 28 days of gesta-
tion. The last phase of construction would be to add enough space
to house all females indoors as shown in Figure 4.
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Table 4. Description of breeding facility Design 2.
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o Boar Crates
28 in W x 8 ft L x 4 ft H
1 1/4 in vertical pipe partitions
Concrete slats, 1 in slot
recessed feed trough in concrete
o Breeding Pen
8 ft W x 9 ft or 9 ft x 10 ft L x 4 ft H
1/0 in guage woven wire floor
2 in vertical pipe partitions with 4 in spacing next to boar stalls
Advantages: Disadvantages:
Breeding activity does not All females must be moved
limit boar movement. through breeding facility for
heat detection
Narrow alleys and general design Usable only for weekly breeding
provide for safe boar handling. unless boar crates are replaced
Mature boars are used for heat with pens or boars are exercised
detection and younger boars can be in breeding pens.
used for actual matings.
Rapid immobilization exhibited
by estrous .
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Design 3
This arrangement (Figure 5) provides space for boars and
females to be located in close proximity from weaning up to 4
weeks post-breeding. Features of this design are described in
Table 5. In typical applications of this design, one boar pen
and 5 sow crates are provided for each female to be bred each
week. Each set of 5 crates houses a newly weaned sow and females
which have been mated 1 to 4 weeks earlier. Thus, with a weekly
breeding schedule one newly weaned sow is added and one sow which
is 4 weeks post-breeding is moved out. Since sows are generally
held here for 3 or 4 weeks post-breeding, more total building
space is required, but the need for an equal amount of space in a
gestation facility is eliminated. Additional space is required
for sows which return to heat and those which are late in return-
ing to estrus after weaning.
When possible, newly weaned sows are placed in a stall
corresponding to the boar to which she will be mated. Sows are
backed out of their stalls for heat detection and mating. Boar
movement between pens is facilitated by providing gates which
open from either end.
Gilts are generally housed within the building in pens.
When detected in heat, they are brought to a boar pen for mating.
Summary
A properly planned and managed breeding facility can greatly
influence the reproductive efficiency of the breeding herd.
Breeding facilities need not be highly sophisticated to be effec-
tive but they must be designed so animals are comfortable and
work routines are easily, quickly and safely accomplished.
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Table 5. Description of breeding facility Design 3.
______________________________________________________________________
o Boar breeding pens
8 ft W x 9 ft L x 4 ft H
Vertical pipe or bar partitions (4 in spacing)
5/16 in diameter or 1/0 guage woven wire floor
Stainless steel feeder in corner of pen partition
Nipple waterer
o Sow stalls
24 in W x 7 ft L
Concrete slats
Easy open and close rear gates
Continuous concrete water/feed trough
Advantages: Disadvantages:
Simple construction. Boar pen serves as breeding pen,
Since females are retained in therefore floor must be designed
facility for 4 weeks, repeat breeders for good footing during mating.
are easily detected and rebred. Boar movement from one pen to
Very little animal movement is required. another is difficult.
Sows within a breeding
group are interspersed
throughout the facility.
Good identification is
essential.
Females must be backed
into breeding pen.
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Figure 1. Gate and latch. Opens both ways and latch stays with gate.
Figure 2. Breeding facility which houses boars, postweaned sows
and replacement gilts.
Figure 3. Individual mating facility with potential expansion
(see top for boar stalls, bottom for boar pens).
Figure 4. Individual mating facility with weaned sow and ges-
tation housing attached (Levis, Univ. of Nebraska).
Figure 5. Individual mating facility which houses boars and
females from weaning through 28-day post-mating.
NEW 6/92 (7M)
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