TECHNICAL PAPER # 39
Vernon M. Meyer
Dr. Eugene Snyder
Dr. Vaughn C. Speer
Wilson Boulevard, Suite 500
Arlington, Virginia 22209 USA
Tel: 703/276-1800 * Fax:
Understanding Swine Production
Volunteers in Technical Assistance
This paper is one of a series published by Volunteers in
Assistance to provide an introduction to specific
technologies of interest to people in developing countries.
The papers are intended to be used as guidelines to help
people choose technologies that are suitable to their
They are not intended to provide construction or
details. People are
urged to contact VITA or a similar organization
for further information and technical assistance if they
find that a particular technology seems to meet their needs.
The papers in the series were written, reviewed, and
almost entirely by VITA Volunteer technical experts on a
Some 500 volunteers were involved in the production
of the first 100 titles issued, contributing approximately
5,000 hours of their time.
VITA staff included Betsey Eisendrath
as editor, Suzanne Brooks handling typesetting and layout,
and Margaret Crouch as project manager.
The author of this paper, Vernon M. Meyer, is an Extension
Engineer with the Iowa State University of Science and
co-author, Douglas Henderson, is an Extension
Livestock Production Specialist working with the same
The reviewers of this paper are all VITA Volunteers.
Pinkston has served in the Philippines as a Peace Corp
specializing in animal husbandry and agriculture.
He is currently
employed with the Defense Contract Administration in New
Dr. Eugene Snyder is a veterinarian, and has been involved
swine breeding and production for many years.
Dr. Snyder also
served for two years as a veterinarian for the Peace Corps
Salvador and the Dominican Republic.
Dr. Vaughn C. Speer is the
Chairman of the Swine Nutrition Research Section, Animal
Department at Iowa State University, and has written over
scientific publications on swine nutrition and management.
VITA is a private, nonprofit organization that supports
working on technical problems in developing countries.
information and assistance aimed at helping individuals and
groups to select and implement technologies appropriate to
situations. VITA maintains
an international Inquiry Service, a
specialized documentation center, and a computerized roster
volunteer technical consultants; manages long-term field
and publishes a variety of technical manuals and papers.
UNDERSTANDING SWINE PRODUCTION
Volunteers Vernon Meyer and Douglas Henderson
Swine production provides red meat for the human diet, uses
feed than is required to produce beef or lamb, and is also a
source of bides and cooking fat.
Swine are also scavengers, and
can make productive use of many materials that would
Pigs (young swine of either sex weighing less than 120
were domesticated in China as early as 4900 B.C.
mention them as early as 1500 B.C., and there are references
to the keeping of swine in Great Britain in 800 B.C.
Today, swine are raised throughout the world.
Their numbers are
particularly high in countries that are heavy producers of
barley, and potatoes.
Countries that have surplus dairy by-products
such as buttermilk and whey also produce many hogs
(domesticated swine weighing more than 120 pounds, raised
market). The only
places where swine production is not suitable
are where religious law (as in Islam and Orthodox Judaism,
example) or strong tradition forbid the consumption of pork.
Even in such places, small operations serving special
Climate is not generally a limiting factor except where it
threatens feed supply.
Swine are raised in both warm and temperate
climates, although young pigs must be kept warm, and
from weather extremes.
Swine production around the world is extremely varied.
are hunted. Single
pigs are cared for and fed, to yield food for
festivities or for routine family fare.
Swine can be produced
efficiently in very small numbers for home or family farm
in larger numbers for marketing.
Large-scale production is more
likely to succeed where cooperative marketing is possible.
The technology of swine production is well developed.
management, housing, health, and marketing systems vary
within and between countries.
In parts of the world where labor
is cheap and capital is scarce, labor intensive systems tend
be used, while production methods in industrialized
tend to be nore capital intensive.
Hogs in some areas are raised
primarily on forage, while elsewhere large numbers are
in total confinement without green feed.
There are many types, breeds, and systems of breeding.
hybrids, and crossbreds furnish most of the world's pork
supply in various grades or quality.
Crossbreeding accounts for
about 90 percent of swine production in the United States
ADVANTAGES OF SWINE PRODUCTION
Swine production has many advantages:
o Swine convert
feed to meat more efficiently than cattle or
A beef steer requires about nine pounds of
to produce a
pound of beef, a lamb requires about eight
pounds, while a
hog requires from four to five pounds of
feed per pound
o Swine are
prolific, commonly producing two litters per year
and from six to
twelve pigs per litter.
o Swine excel in yield
of useable carcass compared to other
produce red meat. Dressing yield is
from 65 to
80 percent for
swine, but 50 to 60 percent for cattle, and
45 to 55 percent
for sheep and lambs.
o Hogs can convert
some wastes and by-products into meat.
garden waste and some types of garbage.
such as food and
garden scraps should be cooked before
being fed to
hogs to help prevent the spread of disease.)
o Very little
labor is required.
It is possible to get by with a small
investment for buildings
o Returns come
quickly. A gilt (young female swine)
bred at eight
months, and the pigs are ready for slaughter
six months after
o Hogs are an
excellent source of home-processed meats.
is due to their
ease of dressing and to the superior curing
qualities of pork.
DISADVANTAGES OF SWINE PRODUCTION
There are also drawbacks:
o A hog's diet
must rely more heavily on concentrates, which
than on roughage, which is cheaper.
requires fairly careful management to achieve
o Swine are very
susceptible to numerous diseases and parasites.
o Swine cannot
utilize pasture as effectively as can cattle
CHANGES IN SWINE PRODUCTION
Type of Hog
During the late nineteenth and early twentieth centuries,
farms in western Europe and North America preferred a hog
produced large amounts of lard, since this was the common
the time. Now,
however, people in many countries use other fats
for cooking, and so a meatier, more heavily muscled carcass,
leaner, bacon-type carcass is preferred.
The demand for cooking
fat in any country is a major factor in determining what
hog to raise.
Swine production methods today vary widely.
speaking, there are two approaches:
the pasture system, in which
the animals are allowed to range over suitable pasture and
confinement system, in which the animals are kept in pens or
Fifty years ago in the United States, confinement systems
Pasture feeding was necessary to provide the
nutrients that cereal grains did not supply.
mineral supplements can provide swine with optimal nutrition
when they do not have access to forage.
This has made possible
the development of confinement systems.
In developed countries,
many swine producers have confinement buildings with
ventilation and other environmental controls.
replaced hand feeding.
Scientifically balanced diets are
provided for each stage in the life cycle.
Slotted floors have
come into common use.
Liquid waste disposal has improved, and
wastes are collected and applied to the land as fertilizer
The result of these changes has been a dramatic speeding up
production. In the
nineteenth century, it took eight to twelve
months to produce a market hog; today, a hog can be ready
market in less than six months.
And it is now possible to
produce several crops of hogs per year; as many as four to
crops are common on many farms.
Hogs are raised in the field on pasture with portable
This system is used if land is not needed for other crop
pasture may be rotated each year to break
disease and parasite cycles and to reseed the pasture.
usually a warm-climate operation.
In the northern cornbelt of
the United States it is used for only one farrowing a
year. If a
second farrowing is produced, the pigs are finished in an
enclosed lot at the farmstead.
Resources, Materials, Equipment Needed
A fenced lot with portable feeders, portable waterers, and
shelter with some bedding are the only resources
A-frame or similar portable shelter is usually used for each
The labor required averages between 24 and 40 hours per sow
No fans or heaters are used with this system, so the only
needed is that used to transport feed and water to the
Cost per sow for one-litter pasture systems (1983 U.S.
averages about $450 for buildings and equipment, and another
for breeding stock and operating costs.
For a two-litter pasture
system, costs would be about double.
Pasture systems require simpler skills and management than
confinement systems do.
Costs for pasture system shelter and
equipment are lower than those for the permanent facilities
involved in a confinement system.
Energy costs are also lower,
and the swine are less subject to crowding and social
A pasture operation is also more flexible than a confinement
operation, expecially a confinement operation with elaborate
facilities. As the
price of corn rises in relation to the
market price of hogs, there comes a point at which it is
profitable to sell the corn than to use it as feed for the
Simple production methods, in which the high-cost items are
and labor, allow the producer to respond as he sees fit in
kind of situation, because his capital is not tied up in
Fewer pigs per litter can be saved in the pasture system.
Weather problems are greater, since the hogs do not live in
It is harder to catch the pigs for
treatment, ear notching, and clipping of eye teeth.
Fencing, feeders, and shelters must be kept in good repair.
Gilts may be farrowed once a year--in warm weather, often on
investment in buildings and equipment can be very
small, but it is charged to only one group of sows and
Or one group of sows may be farrowed twice a year, usually
April and October in the Northern Hemisphere.
If one of the
farrowings is in cold weather, more investment in buildings
equipment is required; costs are charged to twice as many
Confinement seems to have the most benefit for small pigs,
require a particularly stable and controlled environment to
well. Hogs are
raised in buildings designed to provide the best
possible environment, to save labor, and to promote ease of
If pigs are farrowed, nursed, weaned, and started in one pen
until they reach about 60 pounds and 12 weeks of age, they
moved to a finishing unit for the next 12 weeks.
Four litters a
year can be raised this way in two pens in this type of
Some producers farrow three times per year--in temperate
skipping a midwinter litter to leave more time for slower
pigs to reach 220 pounds and to avoid severe weather for
and very hot weather at the end of finishing.
An alternative is to put half of the sows into the stalls
with the largest pigs are weaned and moved
to a nursery pen when stalls are needed for farrowing.
second group of sows and litters stays in the stalls until
weaning. About two
litters are grouped into each nursery pen,
often after sorting by weight and vigor.
For large herds and six or more farrowings per year, it is
to divide production into four stages, with a different enclosure
for each stage:
stalls where farrowing takes place and pigs are
field until weaning; nursery or starting pens; growing pens,
pigs to weights between 75 to 125 pounds; and finishing
pigs up to market weight.
Resources, Materials, Equipment Needed
Buildings for Farrowing.
Farrowing in an enclosed building
allows the manager to control the environment.
Baby pigs must be
kept warm, dry, and free from cold drafts.
A newborn pig needs
an environment of about 90 [degrees] F, then is content with
about a 2 [degrees]
drop per day to 70 [degrees] F.
The sow is more comfortable at about 60 [degrees] F.
To give mother and baby each its own preferred temperature,
necessary to provide supplemental heat in the creep area,
is a pen constructed to exclude larger animals while
young animals to enter and obtain feed.
Farrowing stalls. Farrowing stalls provide the best
small pigs from injury (particularly for the first week or
and require less bedding, floor space, and labor than pens
It is more difficult to catch pigs in a stall.
The stall area may
be used to grow weaned pigs.
Many producers provide water and feed in each stall, while
release the sows twice daily.
Feeding in stalls is especially
recommended for larger herds.
Farrowing stalls are commonly
built from one-inch lumber, 3/4-inch exterior plywood, or
Solid barriers between the farrowing stall
pens can reduce drafts.
Oak or other hardwood is preferred, to
prevent animal damage.
Nursery pens are used from the time the pigs are
weaned at three to six weeks of age.
The pigs are fed in these
pens until they reach a weight of about 40 pounds.
need to be kept at temperatures of from 75 to 85 [degrees] F
weaned, depending on age at weaning.
Wire-mesh floors on raised
decks seem to provide the best environment.
Growing Pens. The
growing stage is the period between the nursery
stage and a weight of about 100 pounds.
Feed conversion is
highest at 60 [degrees] F, but this optimum environment for
may require a large investment in buildings and equipment.
Growing pens may be:
pens in a separate building, pens in a
combination growing-finishing building, subdivided finishing
pens, or full-sized finishing pens.
Finishing is the stage from pig weights of about
100 pounds to market size.
Pigs are finished on pasture,
shelter, and dry lot, open-front buildings, or incomplete
finishing pigs can stand low temperatures,
fastest growth with least feed occurs at temperatures of
55 [degrees] F and at relative humidities of 50-80 percent.
For confinement systems, required labor ranges from 11 to 21
hours per sow and litter.
Confinement systems may require supplemental heat and energy
operate ventilating fans.
Adequate insulation can minimize fuel
costs, and some natural ventilation can replace fans.
The higher cost of the confinement system makes it important
the facility be fully used.
A multiple farrowing schedule should
be used to keep the buildings operating at design capacity,
shutdowns only for major cleaning and sanitation.
Cost per farrowing space for a high investment confinement
(1983 U.S. costs) is $895 for buildings and equipment, and
for breeding stock and operating costs.
Where labor costs are high and capital is not too expensive,
confinement system is advantageous because it substitutes
for labor. It makes
possible automatic feeding and a controlled
environment. It uses
less land than a pasture system does,
reduces the distance that feed and water need to be
allows manure to be more efficiently collected for use as
fertilizer, and makes it easier to sort and pen groups for
Compared to pasture production, confinement production
greater management skill and a higher investment with less
in confinement are also more vulnerable to
All automatic equipment, such as fans, heaters, and feeding
equipment, need routine maintenance.
Two or more groups of sows are each farrowed twice a year.
In temperate climates confinement buildings are essential
Because the facilities are charged to many pigs,
the cost per pig may be the lowest of all possible
III. DESIGNING THE
SYSTEM RIGHT FOR YOU
Capital, labor, land, feed, producer skills and preferences,
climate are all factors influencing the choice of a system.
Four Common Choices
Four common production systems are compared here.
systems produce pigs and carry them to market weight (around
In this program, gilts are farrowed once, then
marketed. All pigs
are raised and sold as market hogs, except for a new group
gilts, which is saved back to continue the production
system makes good use of fenced cropland that is farmed in
rotation, and building and equipment investments are
However, it is risky, especially with regard to animal
performance and product price.
Predators and weather pose a
constant threat to young animals; and because each year's
sold in one short period, there is always the danger of a
Therefore, a one-litter has an element of
risk, but needs supporting enterprises to provide income
This system is suitable when you need a livestock enterprise
add business volume or utilize salvage resources.
operates on a six-month cycle, with saws farrowing in late
and late summer.
These farrowings can be scheduled to use labor
that is available during periods of little crop production
to success are herdsmanship skill and
cropland suitable for hog pasture.
Low-Intensity Confinement System
This system is most often used when the production of hogs
secondary to the production of other crops.
The hog production
operation is maintained with seasonal labor and resources
buildings, fences, materials-handling equipment, etc.) that
not needed for the primary activity.
Buildings are simple in
design, with a minimum of environmental control and
are usually scheduled to avoid the peak
labor periods for crop production.
A popular four-times-a-year
farrowing sequence in the Northern Hemisphere is December
February, June and August.
Although the sow herd may glean grain
fields and graze available pasture, this confinement system
not keep good land out of crop production.
High-Intensity Confinement System
This system uses specialized buildings and equipment,
self-cleaning (slatted or flushed) floors, liquid manure
handling, automatic ventilation, and automatic feed
Because this is a confinement system, it frees the land for
production of other crops.
However if the large investment that
the confinement facilities involve is to pay off, the
must be put to full use.
There must be at least six farrowings a
year, at regular intervals, and hog production must take
precedence over other crops in the allocation of available
resources. This kind
of high intensity farrow-to-finish
production is very demanding, and may be more manageable if
unit is large enough to justify employing two or more
FEED FOR SWINE
The basic energy sources for swine are cereal grains:
(maize), milo (sorghum), barley, wheat, and their
Cereal grains are high in carbohydrates, as well as
easily digested. But
they usually contain less protein, minerals,
and vitamins than swine require; therefore, they must be
with other feeds to increase consumption of these nutrients
to recommended levels.
Although somewhat bulkier than the
cereal grains, grain by-products have much the same
as the grains from which they originate.
Corn contains less protein but more energy than the other
composition of corn, like that of all other
cereals, is influenced by variety, growth conditions, method
harvesting, and storage.
Because of its abundance and readily
available energy, corn is used as the base cereal when the
nutritional value of other cereal grain is given.
Milo, or grain
sorghum, is very similar in quality to corn and can
replace corn in swine rations.
Its energy value is about 95
percent of the value of corn (except for some bird-resistant
varieties, which may offer only be 80-90 percent of the
value of corn).
Table 1 shows the relative feeding values of a
number of feeds.
Table 2 lists feed requirements in terms of corn equivalent
each of the four production systems described above.
Production systems vary in quantity and quality of labor
Pasture systems and low-investment confinement systems
tend to require hard physical labor and to expose the
mud, manure, and inclement weather.
High-investment systems that
use slatted floors and handle manure as a liquid virtually
manual labor, but the work is confining, and odors may be
systems provide margin for error: the
and green vegetation that they offer permit the operator to
late or inexact and still avoid problems of nutrition,
cannibalism, and disease.
As intensity of production increases,
so does the required level of technical skill.
Operators of high
investment, high-intensity systems need to be skilled in
production scheduling, use of medications, and building and
Table 3 shows amounts of labor required.
SIZE OF OPERATION
When the swine operator is intended to produce a significant
income, the minimum sizes shown in Table 4 are suggested.
TABLE 1. Relative Feeding
Maximum recommended percent
of complete rations(3)
energy value vs.
Ingredient (air dry)
Animal fat (stabilized)
Barley (48 lb/bu)
1,275 85- 95
Beet pulp, dried
1,020 70- 80
Bulky, high fiber,
Corn (high lysine)
1,227 90- 95
Milo (grain sorghum)
Oats (36 lb/bu)
1,200 80- 90
Oats (high protein)
Low energy, partial
Potatoes (220 D.M.)
Should be cooked,
Low energy, low
1,450 90- 95
1,500 90- 95
Wheat, high protein
(1) Based on an air dry basis unless otherwise noted.
(2) Feedstuffs must be converted to an air dry equivalent of
dry matter to
determine energy and substitution rates.
data on all
ingredients not available.
(3) When fed at no more than maximum recommended percentage
(4) Higher levels may be fed although performance may
(5) Some "bird resistant milos" are 80-90s vs.
2. Feed Requirements and Feed
for Various Pork Production systems(*)
Feed per Unit of Production
System Bushels of Corn
Pounds of Pur-
Pounds Feed per
Feed cwt. Produced
Per Sow Unit
Per Wt. Gain
(*) Relative feeding values of some other feedstuffs are
the following table.
Estimated Labor Requirements in Swine
Hours of Labor
per sow unit
One-litter pasture system
Two-litter pasture system
Low-investment confinement system
High-investment confinement system
Suggested Size of Swine Production
One-litter pasture system
Two-litter pasture system
Choosing a market is one of the important decisions a hog
producer must make before sale of slaughter hogs.
selected may affect income and profitability.
Prices vary among markets.
Marketing costs, such as selling
charges, transportation, also vary.
Shrinkage, or the difference
between the original weight of livestock and that after it
been prepared for market, will also affect the price.
hog producers need to be aware of alternative markets and to
choose the one which yields the greatest net return.
In the United States, about 70 percent of the nation's hogs
sold by producers themselves.
That is, the producer negotiates
directly with a buyer, and the price is established in the
main advantages of direct marketing from
producer to packer are that hogs are farm fresh, handling
shrinkage are kept to a minimum, and transportation costs
Some producers, about 29 percent in the United States,
sell through public markets.
Producers who choose this method
may feel they themselves do not have sufficient skills to
negotiate with buyers, or they may want to support public
for the good of the industry.
Some producers choose to market as a group, called a
basic purpose of these marketing organizations
is to negotiate either higher base prices or higher quality
premiums than are generally paid for hogs.
organization usually agrees to supply the slaughter plant
specific number of hogs either daily or weekly.
techniques for evaluating hog quality have been developed by
One group bases hog premiums on a sample
cut-out of a producer's hogs rather than individually
each hog or group of hogs as they are marketed.
The major advantage of cooperative marketing organizations
that they can reduce buyer procurement costs while bettering
bargaining position of producers, thereby improving net
for both seller and buyer.
Cooperatives have often been able to
tailor their marketing program to the needs of the
at the same time to supply buyers with the type of hog
USE OF LOCAL RESOURCES
What building materials are available locally will influence
choice of construction.
The type of feed and bedding available
will determine some of the equipment and facility to include
Maintaining animal health is one of the biggest problems of
producers in the United States.
A good program of sanitation and
preventative medicine is advisable.
With high-intensity confinement systems, cash flow can also
financial planning is a must when considering
this type of facility.
SPACE REQUIREMENTS AND SPECIFICATIONS
Appendix TABLE 1.
Pasture Space depends on Rainfall and Soil
sows per acre
7 sows with
litters per acre
50 to 100
growing-finishing pigs per acre
Appendix Table 2. Shade Space
2/sow and litter
2/pig to 100 pounds
2/pig over 100 pounds
Appendix Table 3. Waterer Space
Minimum of two
waterers per pen
pounds): 10 pigs per waterer
pounds): 15 pigs per waterer
4. Floor and Lot Slopes
1/4" - 1/2" per foot without bedding
1/4" per foot with bedding
foot without bedding
1/4" per foot with bedding
1/2" per foot
Paved feeding floors:
1/4" per foot
1/2" per foot
foot crown or side slope
foot to drains
Appendix Table 5.
Per-pig Space Recommendations for Enclosed
Weight Pound Area foot 2
Farrowing stalls a
12-30 2-2 1/2
Nursery pens b
Growing pens b
Finishing pens b
a Avoid concrete slats, slats over 2" wide, and partly
b For slotted, flushed, or scraped floor.
Appendix Table 6. Shed with Lot
More lot area is
often provided to facilitate manure drying.
ft /hd ft
Sow in breeding
7. Animal Sizes, Pen Capacity, and
Solid Totally or Partly
a Or flushed open gutter.
Open gutter not recommended in breeding
because of slick floors.
Appendix Table 8. Feeder Space
sow, 2'/group-fed sow.
Pig (12-30 pounds):
2 pigs per feeder space
Pig (30-50 pounds):
3 pigs per feeder space
Pig (50-75 pounds):
4 pigs per feeder space
Pig (75-220 pounds):
4-5 pigs per feeder space
Appendix Table 9. Water
Sow and litter
Appendix Table 10. Ventilation,
Sow and litter
(*) 300 cfm for gestating sows in a breeding facility.
Appendix Table 11. Slot Widths
floors. Wire mesh, metal, or plastic
preferred in farrowing and prenursery.
Sow and litter
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Pork Industry Handbook.
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Herd Health (19
Housing (21 fact
Pork and Pork
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