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Understanding EPDs - Expected Progeny Differences
EPD’s are Expected Progeny Differences and are considered the most powerful tool available in making genetic progress in
different animal traits. To use EPD’s most effectively one must start by understanding EPD Breed Averages and how an
individual compares to breed average. The EPD’s of the Red Angus
$ Indexes:
Though EPDs allow for the comparison of genetic levels for many economically important traits, they
only provide a piece of the economic puzzle. That’s where $ indexes come in. Through well-conceived, rigorous
mathematical computation, $ indexes blend EPDs and economics to estimate an animal’s overall impact on your
bottom line.
All-Purpose Index (API):
Evaluates sires for use on the entire cow herd (bred to both Angus first-calf
heifers and mature cows) with a portion of their daughters retained to maintain herd size and the remaining
heifers and steers put on feed and sold grade and yield.
Terminal Index (TI):
Evaluates sires for use on mature Angus cows with all offspring put on feed and sold grade
and yield.
Using API and TI
:
First, determine which index to use; if you’re keeping replacements use API. Then, just as with
EPDs, focus on the unit difference between bulls. As described above, index units are in dollars per cow exposed.
The difference can be used to determine how much you can pay for one bull compared to another. For example,
when buying an all-purpose-type sire, you can quickly figure a bull scoring +100 for API is worth an extra $6,000
over a +50 bull if both sire 30 calves/year over 4 years ($50 diff. x 30 hd. x 4 yr. = $6,000).
Lot:4
3/4 Red Angus 1/4 Simm
BLACK HERDMASTER 745B
API 129 TI 76 AOD 5
Born
Birth Wt.
Wean Wt.
Year Wt.
Scrot.
2-3-14 86
654
1346
39.5
ADG
WDA
Rib Fat
IMF
REA
4.5
3.4
.16
.45
16.4
CE-EPD BW-EPD WW-EPD YW-EPD Milk-EPD
5
-.03
45
101
22
Carc. Wt.
YG-EPD BF-EPD Marb.-EPD REA EPD
19.4
-.31
.02
.67
.53
Sire: Trinity
Dam: 407P
MrBeef/King Rob
Footnotes about the bull.
Data Explanations
Catalog Lot #
Average Daily
Gain in our test
Weight per day of age
Sire of the bull
Adjusted 365 Yearling Wt
.
Adjusted Yearling Scrotal
Dam ID
Dam’s Sire
Dam’s Maternal
Grand Sire
Adjusted 205 Weaning Wt.
All bulls are polled unless noted here.
(Scurs)
Bull color and ID
Ultrasound Data- REA &
IMF Adjusted to 365 days
Date born and actual BW
EPDs generated by Simmental Association.
*We have adjusted the EPDs on a few bulls missing a granddam in the ASA database. These are marked
with an *.
Actual rib fat taken at
ultrasound
API and TI Indexes
Age of Dam
Understanding EPD’s- Expected Progeny Differences
Expected Progeny Differences are the most effective tool to compare the genetic differences of two
individuals for various traits. The Simmental breed has calculated comparable EPD’s for all the sires and
hybrid bulls selling. Consequen ly, all the Herdmaster bulls, Simmental sires, Angus ires and Red Angus
sires in this catalog ca be compared to ach other on an EPD basis. Some of the bulls have dams or grand
dams that are not in the Simmental Assn. database. The computer calculates the genetic contribution
from the dam or grand dam as zero. The resulting EPD’s do not accurately reflect the bull. Consequently
we have adjusted those EPD’s to give a more accurate evaluation. These EPD’s are marked with an *.
Breed Composition
All EPDs are designated by a
GRAY colored heading bar.
Actual data under black bar
