Invest: to put (money) into business, stocks, bonds, etc.,
for the purpose of obtaining a profit; to spend or pay money with
the expectation of some satisfaction (Guralnik, 1982).
A person who invests in stocks and bonds expects a return on the
investment. The investment may be a sure thing, or a pretty good-sized
risk. It may be relatively inexpensive to invest, or it may require
a good chunk of change. Each person must decide on an optimum
combination of risk, cost, and possible return on investment.
They must also factor in whether an investment is short-term
or long-term. Longer-term investments can afford to ride out
the ups and downs of the market, as long as the returns continue
to grow over time.
So how does this apply to swine genetics? If you've ever implemented
a crossbreeding system, chosen to buy animals from a particular
breed or line, made decisions about which seedstock supplier to
buy pigs from, or had a hand in deciding which animals to keep
in the herd, you've invested in genetics. How good an investment
it was depends on how well you know your own herd, your understanding
of the genetic principles at work, and the skill with which you
use the information available to you. Savvy investors know that
a good understanding of principles is key, as is knowledge of
the cost of the potential investment, the risk it involves, and
the potential returns. This presentation will focus on those
areas, and lay out some possible investments in genetics.
Review of Genetic Principles
P = G + E. This equation is the starting point in understanding
the role of genetics in pork production. In words, the performance
(Phenotype) of an animal-whether it be number of
pigs born alive, growth rate, or muscle pH-is due to a combination
of its Genes and its Environment.
The application of genetic principles is predicated on the assumption
that we can measure performance with some accuracy and precision,
and that we have some knowledge of how genetics and environment
influence that performance.
Effective selection-the choice of which animals
will become parents-will result in genetic change over time.
Traditional selection programs (Cleveland et al., 1998) are analogous
to longer-term investments. The incremental changes tend to be
small, but gradually accumulate. To practice selection, we must
be able to measure performance objectively. We must also be able
to tease apart the genetic and environmental effects that make
up performance, because only the genes are passed on to the next
generation. Because genes are passed on from generation to generation,
however, the effects of selection are permanent. Genetic change
also accumulates over time as long as the same selection criteria
are used. To maximize the rate of genetic change, performance
must be measured objectively, accurately and precisely. A trait
which is influenced to a greater degree by genetics (more highly
heritable; Table 1) will change more rapidly than one which is
not. Choosing a minimum number of the best candidates for selection,
and replacing older animals as rapidly as possible with better
offspring, will also maximize genetic change. Selecting both
male and female parents also speeds up progress, as will focusing
on a single trait. Trying to improve several traits at the same
time will slow down progress, especially if any of the traits
are antagonistic to each other (unfavorably correlated; Table
1). For example, a carcass trait like backfat depth is strongly
influenced by genetics, which is good; but selection for extreme
leanness is likely to hurt reproductive performance and meat quality
traits, which is bad. Thus, the choice of traits on which to
practice selection is very important. New knowledge and technologies
in molecular genetics will allow us to speed up the rate of genetic
change by manipulating genes directly (Rothschild and Ruvinsky,
1998), but the principles of selection remain the same.
Because genetic change is permanent and cumulative, the question
is often asked, "During tight times, why not just let the
herd coast?" Remember that while we tend to talk about genetic
improvement, which implies a change in the desirable direction,
change can also occur in the opposite direction. Ignoring genetics
is not really an option unless you are willing to take the risk
of adverse genetic change. More on this topic later in
Does selection really work? Sellier and Rothschild (1991) reviewed progress in several populations around the world, and determined that annual rates of change included -0.1 to
-0.5 mm of backfat; 0.2 to 0.5 cm2 increased loin area;
and an improvement of 0.3 to 0.6 % carcass lean content. Progress
in reproductive traits can be expected to be slower, but steady.
To remain in business, seedstock suppliers MUST be making genetic
progress in traits that are important to their commercial customers
(Mabry et al., 1988). Furthermore, successful suppliers must
also be thinking two to five years ahead of current conditions,
because it takes at least that long for changes in the seedstock
herds to trickle down to the commercial level (Schinckel et al.,
Choice of a mating system, in particular a crossbreeding
system, often represents an investment in genetics with a shorter-term,
more dramatic return than selection. Crossbreeding allows a producer
to take advantage of the fact that the combination of genes inherited
from the parents can result in an extra boost in performance (heterosis).
The fewer genes the parents have in common, the bigger the boost.
Even better, traits which do not respond very well to selection
because they are lowly heritable often exhibit the most heterosis.
And to top it off, lines or breeds can be chosen to complement
each other; strengths in one can balance weaknesses in the other.
For all these reasons, crossbreeding is almost universal at the
commercial level (Ahlschwede et al., 1987).
Again, however, paying attention to your genetic investment will
pay dividends. Just like selection, crossbreeding is a two-way
street. Heterosis is a great concept: it can give a herd a jump-start.
But lack of a good plan for a crossbreeding system, or not really
paying attention to its proper implementation, can create a jumbled
mess. Shortcuts just don't work very well. As a result, many
commercial herds today use a terminal crossbreeding system in
which all pigs are sold for slaughter. Such systems maximize
short-term benefits, but replacement gilts and boars must be brought
in, which can mean a further investment in appropriate biosecurity
|Table 1. Heritabilities and genetic correlations of important traits in swinea|
|Number born alive|
|Adj. 21-d weight|
|Days to 250 lb|
|Average daily gain|
|Loin muscle area|
|% carcass lean|
|a Heritabilities are on the diagonal, genetic correlations are above the diagonal. Values come from NSIF (1997) and NPPC (1995).|
|b B-mode (real-time) ultrasound.|
For a commercial producer to fully realize the potential from
investing in genetics, both selection and crossbreeding must be
considered (McLaren and Schinckel, 1987). To accomplish that
goal, decisions about the kind of mating system, the breeds, lines
or combinations, and (or) seedstock supplier must be made. Finally,
the actual boars and (or) gilts should be chosen based on performance
testing. EPDs are the most accurate estimate of breeding value
(the value of an animal as a parent) we have right now. They
do vary in how well they will predict progeny performance, depending
on the types and amounts of information available, so the amount
of risk in selecting animals will vary as well. Selection risk
can be decreased by paying attention to EPD accuracies (See, 1994b).
Don't ignore a boar with an excellent EPD but fairly low accuracy.
Just don't bet your farm on him by breeding him to all your sows.
It is also important that the genetic program of the seedstock
supplier be compatible with what you want to achieve, and that
genetic progress is being made at the seedstock level. As See
(1996) explains in some detail, a sound genetic improvement program
includes 1) accurate, complete performance records; 2) assessment
of genetic merit; 3) indexes for multiple trait selection; and
4) selection of the highest ranking replacements based on the
indexes. Indexes are important because several traits are usually
important to a producer, and indexes optimize progress in all
traits that are included (Wood and See, 1997). One of the best
ways to evaluate the success of a genetic improvement program
is to study the genetic trends to make sure the desired traits
are going in the correct direction.
Finally, to make sure the genetic program is working for a particular
farm, it is important that management and environment match the
genotype. Careful records of results should be kept, even if
the producer is buying a genetic package from a seedstock supplier.
More and more producers are going that route. They have found
that in return for a higher cost up front, the buyer gets the
advantages of selection and crossbreeding without the headaches
of managing the genetics. In fact, in many ways, the area of
genetics has followed the same evolution as nutrition: everyone
used to mix their own feed, but now many producers prefer to pay
feed companies to perform that task and keep track of new technologies
and improvements. Just as it pays to collect feed samples, however,
it pays to keep records on the genetics.
Economic Value of Traits
Part of a good investment strategy is to prioritize goals, short
and long term. In terms of investing in genetics, consideration
of the economic value of traits is a huge factor in deciding which
ones to emphasize, and how to improve them. Each producer must
make the final decision on which traits to emphasize, based on
individual circumstances like current performance of the herd
or market premiums and discounts. In today's industry, producers
must stay in touch with what is occurring all up and down the
pork chain, and sort out what that means for them. Baas (1998)
lays it out very nicely. Producers need someone to buy the pigs,
while reducing the cost of production to maximize profit. Packers
want to keep the customers (consumers) happy, keep the kill line
full, maximize lean in the carcass while minimizing meat quality
problems, enhance uniformity, and pay as little as possible for
the pigs. To meet those (often conflicting) demands, producers
must market pigs that come from large litters, convert feed into
lean meat efficiently, and yield a product that is acceptable
to the packer.
That's a tall order, and genetics won't get the entire job done,
but a good place to start is with the economic values in Table
2. For example, based on the values in Table 2, an extra live
pig is worth $13.50, a value which far outweighs the relative
value of any other trait. But litter size is a lowly heritable
trait which will respond slowly, albeit surely, to selection.
Heterosis from crossbreeding will give a much greater improvement
in litter size in the short term. Should selection for increased
litter size be ignored? Of course not. It's worth too much.
But under some situations, simply maintaining litter size may
be sufficient, which may allow for a larger investment in other
|Table 2. Composite estimates of economic values of traits important in swinea|
|Number born alive|
|Adjusted 21-day litter weight|
|Days to 250 pounds|
|Average daily gain|
|Loin muscle area|
|% Lean (carcass)|
|a From NSIF (1997) and NPPC (1995). Relativeeconomic value = [standard deviation * economic value/unit] compared to that of backfat.|
|b B-mode ultrasound.|
Economic values, coupled with EPDs, are often used to illustrate
how much more one boar might be worth than another one. This
can be helpful information if the choice is down to one animal
or another, but it is always important to keep in mind what is
needed for a particular herd.
Putting It All Together
Seedstock suppliers in today's pork industry know the value of genetics, and have invested a great deal of time and money in their genetic improvement programs. All of the major breed associations have programs in place to take advantage of the principles of genetics as they apply to purebred animals. A number of them have also developed crossbreeding systems to help their commercial customers achieve the maximum benefit from the genetics they buy. Companies that sell hybrid seedstock likewise have improvement programs in place, and spend considerable time on developing crossbreeding systems that will profit their customers. Forward-thinking seedstock suppliers are working today to anticipate what will be needed by the industry five to ten years down the road, genetically speaking. In most cases, these projects are costly in that some results (pigs) must be discarded (sold for slaughter, rather than as breeding stock) and the learning curve on new traits can be steep. The bottom line for the seedstock industry is that a reasonable return on investments is needed to continue making genetic progress. For that reason, if no other, many breeding animals are sold on a sliding scale: the more superior the performance, the higher the price.
On the other hand, the perspective from the commercial producer
is somewhat different. The commercial producer wants breeding
stock that will produce market hogs that meet packer demands while
lowering production costs, and at as low a purchase price as possible.
In today's market situation, short-term costs and benefits can
certainly outweigh the longer-term ones. Hence the questions
that are heard so often: "How much can I afford to pay for
a better boar/gilt? What kind of crossbreeding system should
I use? How much can I really afford to spend on genetics?"
Examples of determining what a good boar or gilt is worth are
easy to find. Ensminger and Parker (1997) calculate that a boar
whose progeny exhibit a 5% improvement in feed efficiency, gain
5% faster, bring a $1.50/cwt premium at slaughter, and include
an extra 0.1 pig sold per litter could increase profitability
by $16,000 in one year, assuming the boar sired 1,496 pigs. See
(1995) calculated that for every 0.1 in (2.54 mm) reduction in
backfat, there is an 11.8 lb reduction in the amount of feed required
per pig per day, and a $1.50/head carcass premium. By reducing
the number of days to market by one day, 3.1 lb less feed is required
and fixed costs are reduced by $0.17. All this information was
used to calculate the difference between buying genetically improved
gilts and keeping gilts from a herd with no genetic improvement.
In his example, the improved gilts were 0.1 in leaner, had 0.3
more live pigs per litter, weaned 0.2 more pigs, and improved
litter weight by 5 lb. Assuming the sows averaged four litters
and 10 pigs per litter, the additional value of the purchased
gilts would be $128.80 each. Using results from NPPC's Genetic
Evaluation Terminal Line Program (Goodwin and Burroughs, 1995),
it is even possible to compare individual animals from the various
populations that participated in the program.
As for the kind of crossbreeding system to choose, at the commercial
level there are two types that seem to make the most sense in
today's industry: terminal systems and rota-terminal systems.
The traditional rotational cross gives up too much heterosis
(86% vs. 100% for a terminal cross) for a lot of producers, results
in less uniform groups of animals, and makes selection programs
harder to implement (Ahlschwede et al., 1987).
In most cases, the choice of a terminal or rota-terminal system
comes down to the decision about raising or buying replacement
gilts, especially now that artificial insemination and commercial
boar studs have made it possible for even smaller herds to obtain
superior genetics on the boar side at a reasonable cost (See,
1996). In addition to the kinds of calculations given in the
previous paragraph, other costs and intangibles often play a role.
"Service after the sale" comes with the purchase of
gilts oftentimes; raising gilts may lower total investment in
breeding stock (plus capital gains in some cases). According
to simulations conducted by See (1994a), there was only a $300
range in net return for three gilt options: purchase of commercial
lines as a package, purchase of specialized grandparent lines
for multiplying, and rota-terminal (home-raised gilts). The simulation
assumed equal genetic merit for all three options. Obviously,
the cost of germplasm could change that range. One example would
be the cost of your grandparent stock compared to what semen would
cost to produce your own replacements in a rota-terminal system.
Another factor to consider is management. To make a rota-terminal
system work requires an excellent record-keeping system, a good
understanding of performance testing, and a willingness to keep
after it. Frankly, if an enterprise has been ignoring genetics,
it probably would be best to consider depopulation and a total
change in breeding stock. The short-term costs will be high,
but the long-term results would be well worth the expense.
If the decision is to go with buying a terminal system "package"
that includes gilts and boars, then the logical next step is to
determine which one(s) fit each particular situation, and the
budget. Good, terminal-cross lines are going to cost more. The
types of calculations outlined above can be used to "comparison
shop" different product lines, but always be sure you are
comparing like to like. To really get a good handle on how much
a better animal is worth to you, you have to first know exactly
where your current animals are for the same trait(s). And if
the traits are new, like some of the meat quality traits that
are being considered by packing companies as payment criteria,
availability of animals can become a real issue. Do commercial
producers need to worry about those meat quality traits right
now? A year or two ago, the answer was to keep an eye open.
Now, the answer probably should be in the form of a question,
"What pork quality issues most interest my packer?"
Are those quality traits measurable objectively? Examples include
those in Tables 1 and 2, but that list is not comprehensive.
Do those traits have a significant genetic component to them?
If you answered "Yes" to the last two questions, then
it's probably time to start looking for a seedstock supplier who
is already working on a genetic improvement program that includes
those traits, because the genetic lag time can be considerable.
Commercial producers who wait for implementation of buying systems
that include quality measures before doing anything about it will
be in the same situation as those who waited for the big push
on grade and yield buying systems implemented in the past five
or six years: playing catch-up.
"How much can I really afford to spend on genetics?"
With $17.00 hogs, that question is very difficult to answer objectively.
From a geneticist's point of view, the answer has to be, "As
much as you can," but that's not very useful to someone who
is swimming in red ink. As with so many such decisions, it probably
hinges on whether a producer (and the banker) is an optimist or
a pessimist, or somewhere in between, and how adverse to risk
they are. If hunkering down and waiting for the market to shift
is your style, then no one is going to be able to convince you
to spend much money on any kind of improvements, genetic or otherwise.
If you believe the market is going to head back up and you want
to be ready to take full advantage of that inevitable turn, then
investing a significant amount of capital to make sure the genetics
are right could be a wise move. If you are convinced that investing
in genetics is the right thing to do, and you really do want to
make improvements, but laying out a lot of cash right now is an
ulcer waiting to happen, then temporize. Improve your
record keeping if necessary to keep track of genetics and performance
on your farm. Use EPDs in buying replacement animals,
and consider paying a bit more for a better boar. Who
knows, you may get a pretty good deal. Investigate the
new traits and various seedstock suppliers. Include investments
in genetics as part of your long-term management plan so you'll
be ready to make a major investment when the time is right.
The Bottom Line
We often get asked, "Can I afford to invest in genetics?"
I would turn the question around: "Can you afford NOT to
invest in genetics?"
Ahlschwede, W.T., C.J. Christians, R.K. Johnson,
and O.W. Robison. 1987. Crossbreeding systems for commercial
pork production. In: Pork Industry Handbook (PIH-39).
Purdue Univ. Coop. Ext. Serv., W. Lafayette, IN.
Baas, T.J. 1998. Genetics play important role in
bottom line. Feedstuffs 70(43):11.
Cleveland, E.R., A.P. Schinckel, and C.M. Stanislaw.
1998. Genetic principles and their applications. In: Pork
Industry Handbook (PIH-106). Purdue Univ. Coop. Ext. Serv.,
W. Lafayette, IN.
Ensminger, M.E., and R.O. Parker. 1997. Swine
Science (6th Ed.), pp 55-56. Interstate Publishers,
Inc., Danville, IL.
Goodwin, R., and S. Burroughs (Ed.). 1995. Genetic
Evaluation: Terminal Line Program Results. National Pork Producers
Council, Des Moines, IA.
Guralnik, D.B. (Ed.). 1982. Webster's New World
Dictionary of the American Language, Concise Ed. The
World Publishing Co., New York.
Mabry, J., G. Isler, and W.T. Ahlschwede. 1988.
Selection guidelines for the seedstock producer. In: Pork
Industry Handbook (PIH-58). Purdue Univ. Coop. Ext. Serv.,
W. Lafayette, IN.
McLaren, D.G., and A.P. Schinckel. 1987. The economic
impact of genetic improvement. In: NSIF Swine Genetics Handbook
(NSIF-FS 1). Purdue Univ. Coop. Ext. Serv., W. Lafayette, IN.
Rothschild, M.F., and A. Ruvinsky (Ed.). 1998.
The Genetics of the Pig. CAB International, New York.
Schinckel, A.P., C.J. Christians, and R.O. Bates.
1987. Boar selection guidelines for commercial pork producers.
In: Pork Industry Handbook (PIH-9). Purdue Univ. Coop.
Ext. Serv., W. Lafayette, IN.
See, M.T. 1994a. Should replacement gilts be raised
or purchased? ANS Factsheet (ANS 94-802S), North Carolina Coop.
Ext. Serv., Raleigh.
See, M.T. 1994b. Using expected progeny differences
for swine selection. ANS Factsheet (ANS 94-801S), North Carolina
Coop. Ext. Serv., Raleigh.
See, M.T. 1995. The economic value of genetic improvement. Swine News 18(2).
See, M.T. 1996. Efficiency of genetic transfer
using AI technology. In: Proc. of the Amer. Assoc. of Swine
Practitioners 27th Ann. Mtg. Mar. 2-5, 1996, Nashville,
Sellier, P., and M.F. Rothschild. 1991. Breed identification
and development in pigs. In: Maijala, K. (Ed.) Genetic Resources
of Pig, Sheep and Goat, World Animal Science, B8, pp 125-143.
Elsevier Sci. Publishers, Amsterdam, The Netherlands.
Wood, C.M., and M.T. See (Ed.). 1997. Guidelines
for Uniform Swine Improvement Programs. National Pork Producers
Council, Des Moines, IA.