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The more cow-calf producers know about the bulls they buy, the more they can take advantage of the genetic forces—selection and
mating—that drive the productivity and value of each calf crop. With genomic-enhanced expected progeny differences (GE-EPDs)
and percent ranks powered by High-Density (HD) 50K and i50K from Zoetis, commercial users can unlock the power of these forces
like never before.
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The value of GE-EPDs powered by HD 50K and i50K
HD 50K and i50K for Angus include genetic predictions in the form of GE-EPDs and percent ranks for 19 traits, six indexes plus
parentage verification. For most of these traits, Angus Genetics, Inc. (AGI) computes and reports weekly GE-EPDs, which are the
most accurate genetic predictions possible for young bulls with limited or no progeny. The resulting EPD accuracy is generally
equivalent to tested bulls having an initial progeny proof of roughly 15 calves/carcasses/daughters with performance data
contributing to their EPDs (ranges from 7 to 24 progeny, depending on the trait – Table 1).
Interpreting HD 50K and i50K percent ranks
Genomic percent ranks from Zoetis are currently based on a reference population of more than 225,000 tested Angus animals.
Ranks range from 1 to 100, with lower numbers generally favored for most traits (Table 1). Tenderness (Tend) is the one trait
exclusively evaluated through genomic percent ranks (no GE-EPDs are currently available). Ranks for tenderness explain roughly
one-fourth of the genetic differences in this component of eating satisfaction.
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Selection – Better bull buying for specific purposes
Higher accuracy GE-EPDs and more complete trait information from HD 50K percent ranks help Angus bull buyers more dependably
select bulls for specific purposes, including:
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Heifer bulls –
GE-EPDs for calving ease direct (CED) and birth weight (BW) have accuracies roughly equivalent to bulls
with 24 and 13 progeny, respectively, with calving ease and birth weight data recorded (Table 1).
•
Growth/carcass bulls –
GE-EPDs for growth (WW and YW), feed efficiency (RADG) and carcass merit (CW, Marb, RE, Fat)
have accuracies that are basically equal to bulls having 20, 17 and 10 progeny/carcasses, respectively, with performance
data recorded (average of trait groupings from Table 1).
•
Maternal bulls for making replacements –
GE-EPDs for heifer pregnancy (HP), scrotal circumference (SC), docility (Doc),
milk and mature size (YH and MW) deliver the rough equivalent accuracy of bulls having 16 daughters with performance/
productivity information recorded for these traits (average of trait groupings from Table 1). Percent ranks from HD 50K for
calving ease maternal (CEM) provide information for this important maternal trait, although this genomic prediction is not
currently included in GE-EPDs for CEM.
•
All-purpose bulls –
Across all applicable traits, GE-EPDs powered by HD 50K and i50K have accuracies that are approximately
equal to bulls with 15 progeny/carcasses/daughters with recorded performance (average of all traits in Table 1).
Mating
Besides selection, mating is the other genetic force that drives production. More accurately evaluated bulls may be strategically
matched with sets of females to accentuate strengths and correct weaknesses—creating more valuable progeny, carcasses
and replacements. This is especially true if commercial Angus females are tested with GeneMax® Advantage™ and matched to
complementary Angus sires. (see
As well, HD 50K- and i50K-verified parentage improves the accuracy of EPDs and enables sire match for GeneMax® Advantage™
tested progeny to help minimize inbreeding. It also reliably documents relationships to tested sires and dams that are proven to be
free of known genetic conditions.
Summary
Angus bulls with more accurate and complete GE-EPDs powered by HD 50K and i50K from Zoetis can more dependably be selected
and matched with females for specific purposes to produce progeny with increased productivity.
Better bull buying – GE-EPDs and percent ranks powered by HD 50K and i50K from Zoetis
To learn more, visit zoetisUS.com/genetics or angus.org or contact
your Zoetis or American Angus Association representative.
