Page 10 - Woodbank Matariki 2021 Catalogue ebook

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%. The following guide is given for interpreting accuracy:
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 TACE.

Accuracy range Interpretation
EBV should be considered as a preliminary estimate. It could change substantially
Less than 50%
as more performance information becomes available.
Medium accuracy, usually based on the animal’s own records and
50-74% pedigree. Still subject to substantial changes with more information,
particularly when the performance of progeny are analysed.
Medium - high accuracy and includes some progeny information.
75-90%
Becoming a more reliable indicator of the animal’s value as a parent.
High accuracy estimate of the animal’s true breeding value. It is unlikely
More than 90%
that the EBV will change much with the addition of more progeny data.

8 Woodbank Angus & Matariki Herefords Bull Sale 2021