Page 10 - Capethorne Riverland Grassmere ebook

Eye Muscle Area EBV (sq cm) is calculated from measurements from
live animal ultrasound scans and from abattoir carcase data, adjusted to a
standard 400 kg carcase. This EBV estimates genetic differences in eye
muscle area at the 12/13th rib site of a 400 kg dressed carcase. More
positive EBVs indicate better muscling on animals. Sires with relatively
higher EMA EBVs are expected to produce better-muscled and higher
percentage yielding progeny at the same carcase weight than will sires with
lower EMA EBVs.
Rib Fat and Rump Fat EBVs (mm) are calculated from measurements
of subcutaneous fat depth at the 12/13-rib site and the P8 rump site (from
live animal ultrasound scans and 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.

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.

8 Riverlands, Capethorne, Grassmere Combined Bull Sale 2021