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Better bull buying—GE-EPDs and percent ranks powered by HD 50K from Zoetis
Themore cow-calf producers know about the bulls they buy, themore 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 fromZoetis, commercial users can unlock the power of these forces like never before.
The value of HD 50K
HD 50K for Angus includes genetic predictions in the formof percent ranks for 19 traits plus parentage verification. For most of these
traits, Angus Genetics, Inc. (AGI), computes and reports weekly GE-EPDs powered by HD 50K, which are themost 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 a dozen calves/carcasses/daughters with performance data contributing to their EPDs (ranges from
six to 22 progeny, depending upon the trait —Table 1). Increasingly, Angus bull buyers are demanding tested bulls (Figure 1).
HD 50K percent ranks, interpretation for non-GE-EPD traits
HD 50K percent ranks fromZoetis are currently based on a reference population of nearly 40,000 tested Angus animals. Ranks range
from 1 to 100, with lower numbers generally favored for most traits (Table 1). Some traits for which HD 50K percent ranks are available
do not yet have GE-EPDs. These include ranks for residual feed intake (RFI) and end-product tenderness (Tend).
Percent ranks for RFI provide Angus bull buyers with added feed efficiency information, while ranks for Tend explain approximately
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 andmore complete trait information fromHD 50K percent ranks help Angus bull buyers more dependably
select bulls for specific purposes, including:
• Heifer bulls
— GE-EPDs for calving ease direct (CED) and birth weight (BW) have accuracies roughly equivalent to bulls with
22 and 12 progeny, respectively, with calving ease and birth weight data recorded (Table 1).
• Growth/carcass bulls
—GE-EPDs for growth (WW& YW), feed efficiency (RADG) and carcass merit (CW, Marb, RE, Fat) have
accuracies that are basically equal to bulls having 21, 17 and 10 progeny/carcasses, respectively, with performance data recorded
(average of trait groupings fromTable 1).
• Maternal bulls for making replacements
— GE-EPDs for scrotal circumference (SC), docility (Doc), milk and mature size
(YH and MW) deliver the rough equivalent accuracy of bulls having 12 daughters with performance/productivity information
recorded for these traits (average of trait groupings fromTable 1). Percent ranks from HD 50K for heifer pregnancy (HP) and
calving ease maternal (CEM) provide information for these important maternal traits.
• All-purpose bulls
— Across all applicable traits, GE-EPDs powered by HD 50K have accuracies that are approximately equal
to bulls with a dozen 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 bemore strategically
matched with sets of females to accentuate strengths and correct weaknesses — creatingmore valuable progeny, carcasses and
replacements. This is especially true if commercial Angus females are tested with GeneMax™ and genetic information, and assigned
Angus sires are used for selection andmating (see
).
As well, HD 50K-verified parentage improves the accuracy of EPDs and the precision with which commercial producers canminimize
inbreeding. It also reliably documents relationships to tested sires and dams that are proven to be free of known genetic conditions.
Summary
Angus bulls withmore accurate and complete GE-EPDs powered by HD 50K fromZoetis canmore dependably be selected and
matched with females for specific purposes to produce progeny with increased productivity.
To learn more, visit zoetisUS.com/genetics or angus.org or contact
your Zoetis or American Angus Association
®
representative.
HD50K
