2014 GeneLink - page 4

From Paper to Production
In theory, the principle of genetic
improvement is really quite simple: select
the best individuals to retain as parents
in your herd and disseminate their
genes through the system as quickly as
possible. But, as the saying goes, “ e
devil is in the details.” De ning “the
best” is generally the rst step. is is
where the combination of world-class
breeders and cutting-edge technology
at the National Swine Registry (NSR)
come together to implement a genetic
improvement program to maximize prof-
itability for commercial swine producers.
The Breeders
NSR’s commercially-oriented mem-
bers are world-class breeders, under-
standing the importance of a balanced
approach to genetic improvement. ey
understand that feet and leg sound-
ness and structural correctness are not
only the foundation of a solid breeding
animal, but also the foundation of a solid
genetic improvement program. Decades
of stockmanship experience, most of
which was gained “in the barn” rais-
ing pigs, laid the groundwork for their
understanding of what functional boars
and gilts should look like to provide
robustness and longevity. As a judging
coach told me a long time ago, “It’s all
about form to function.” is means
everything we evaluate visually serves a
function in commercial production.
The Program
e Swine Testing and Genetic
Evaluation System (STAGES™) is the
cutting-edge technology behind the
NSR genetic improvement program.
is is where “the best” is determined.
Our breeders do an excellent job of col-
lecting data for economically-relevant
traits: reproduction, longevity, pre- and
post-weaning growth, carcass measures
and meat quality characteristics. ey
also submit DNA samples for geno-
typing major genes known to impact
economically-important traits, along
with more robust gene marker panels,
including 10K or 60K single nucleo-
tide polymorphism (SNP) markers.
is data, along with pedigree
information provided by the breeders,
are analyzed by STAGES™ to pro-
duce estimates of genetic merit, or the
Estimated Breeding Value (EBV), for
each trait of interest. en, these EBV
are utilized in the calculations for total
genetic merit, called selection indexes.
Each bio-economic selection index is
calculated using a proprietary formula
developed in conjunction with university
experts. e indexes account for all the
di erent economic drivers in pork pro-
duction. Selection indexes are calculated
based on the breeding goal of the breed.
e Terminal Sire Index (TSI) is used
primarily for Duroc and Hampshire pigs
and focuses on growth and carcass merit,
with much emphasis placed on improv-
ing feed e ciency. e Sow Productivity
Index (SPI) is used primarily in the York-
shire and Landrace breeds and focuses on
sow productivity traits: litter size born
and weaned, weaning weight and rebreed
interval. e Maternal Line Index (MLI)
is utilized by Yorkshire and Landrace
breeders wanting to place more emphasis
on terminal traits in their maternal lines
and focuses on a balance of TSI and SPI.
NSR also has the ability to customize
selection index weighting based on the
goals of individual breeders, if they are
di erent from those determined by NSR.
The Paper
Breeders can receive selection index
values on any of their purebred animals
at any time for use in their genetic im-
provement program. Some utilize paren-
tal average index values to determine ani-
mals to cull in a two-stage selection pro-
gram, where not all boars remain intact
through o -test. Most breeders utilize
index values immediately after o -test to
make selection decisions for replacement
boars and gilts. is is the point where
breeders rank their animals from top
to bottom utilizing one of the selection
indexes above. en, they select indi-
viduals of higher genetic merit than what
is currently in their herd/boar stud and
remove animals of lower merit. Breeders
will also pull updated index values at dif-
ferent selection/culling points in a pig’s
life to determine if, for instance, a female
should be relegated to the production of
F1 females or culled altogether. Boars are
also replaced using this updated informa-
tion, replacing older, lower merit boars
with young boars of higher genetic merit.
The Production
By utilizing all available informa-
tion in the estimates of genetic merit
and properly weighing each of these
EBV with real-world economic fac-
tors, NSR breeders are able to select
individuals that will provide the most
genetic improvement, in a balanced
package and drive the pro tability
of their commercial customers.
Dr. Doug Newcom
NSR V.P. of Global Technical Service
4 • 2014 GENELINK
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