Page 9 - Ariki ebook

from abattoir carcases) and are adjusted to a standard 400 kg
carcase. These EBVs are indicators of the genetic differences in
fat distribution on a standard 400 kg carcase. Sires with low, or
negative, fat EBVs are expected to produce leaner progeny at any
particular carcase weight than will sires with higher EBVs.
Retail Beef Yield EBV (%) indicates genetic differences between
animals for retail yield percentage in a standard 400 kg carcase.
Sires with larger EBVs are expected to produce progeny with
higher yielding carcases.
Intramuscular Fat EBV (%) is an estimate of the genetic
difference in the percentage of intramuscular fat at the 12/13th
rib site in a 400 kg carcase. Depending on market targets, larger
more positive values are generally more favourable.
Docility EBV (%) is an estimate of the genetic differences
between animals in temperament. Docility EBVs are expressed as
differences in the percentage of progeny that will be scored with
acceptable temperament (ie. either “docile” or “restless”).

ACCURACY

Accuracy (%) is based on the amount of performance information
available on the animal and its close relatives - particularly the
number of progeny analysed. Accuracy is also based on the
heritability of the trait and the genetic correlations with other
recorded traits. Hence accuracy indicates the “confidence level”
of the EBV. The higher the accuracy value the lower the likelihood
of change in the animal’s EBV as more information is analysed
for that animal or its relatives. Even though an EBV with a low
accuracy may change in the future, it is still the best estimate of an
animal’s genetic merit for that trait. As more information becomes
available, an EBV is just as likely to increase in value, as it is to
decrease.
Accuracy values range from 0-99%.
As a rule, animals should be compared on EBVs regardless of
accuracy. However, where two animals have similar EBVs the one
with higher accuracy could be the safer choice, assuming other
factors are equal.
For further information please contact NZ Angus or TransTasman
Angus Cattle Evaluation.

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