Page 7 - Martin Farming Angus 2021 Catalogue eBook

Retail Beef Yield EBV (%) indicates genetic differences joined in an example self-replacing commercial Angus
between animals for retail yield percentage in a standard herd that targets the production of grass finished steers
400 kg carcase. Sires with larger EBVs are expected to for the AngusPure programme. Steers are assumed
produce progeny with higher yielding carcases. marketed at 530 kg live weight (290 kg carcase weight
and 10 mm fat depth) at approximately 20 months of
Intramuscular Fat EBV (%) is an estimate of the genetic age. Selected heifers are retained for breeding and the
difference in the percentage of intramuscular fat at the balance marketed at approximately 20 months weighing
12/13th rib site in a 400 kg carcase. Depending on market 450 kg (240 kg carcase weight and 10 mm fat depth).
targets, larger more positive values are generally more A significant premium for carcase quality was assumed
favourable. and, as some daughters are retained, maternal traits are
Docility EBV (%) is an estimate of the genetic differences also of importance.
between animals in temperament. Docility EBVs are Heifer/Dairy Terminal Index ($) – Estimates the genetic
expressed as differences in the percentage of progeny differences between animals in net profitability per
that will be scored with acceptable temperament (ie. female joined in an example herd where all progeny are
either “docile” or “restless”). marketed. All progeny are marketed at approximately
510 kg live weight (280 kg carcase weight and 7 mm fat
ANGUS INDEXES depth) at approximately 24 months of age.
There are currently three selection indexes calculated for Note that $Index values for individual animals are
New Zealand Angus animals. These are Self-Replacing, sensitive to the assumptions used in the BreedObject
AngusPure and Heifer/Dairy Terminal. Each selection analysis to calculate the selection index.
index describes a different production/market scenario
and relates to a typical commercial herd in New Zealand ACCURACY
that is targeting the following specifications.
Index values are reported as EBVs, in units of relative Accuracy (%) is based on the amount of performance
information available on the animal and its close relatives
earning capacity ($) for a given market. They reflect both - particularly the number of progeny analysed. Accuracy
the short-term profit generated by a sire through the sale is also based on the heritability of the trait and the genetic
of his progeny, and the longer-term profit generated by correlations with other recorded traits. Hence accuracy
his daughters in a self-replacing cow herd. The Index indicates the “confidence level” of the EBV. The higher
values are derived using BreedObject technology. the accuracy value the lower the likelihood of change
Self-Replacing Index ($) - Estimates the genetic in the animal’s EBV as more information is analysed for
differences between animals in net profitability per cow that animal or its relatives. Even though an EBV with a
joined in an example self-replacing commercial herd that low accuracy may change in the future, it is still the best
targets the production of grass finished steers. Steers estimate of an animal’s genetic merit for that trait. As
are assumed marketed at approximately 480 kg live more information becomes available, an EBV is just as
weight (265 kg carcase weight and 7 mm fat depth) likely to increase in value, as it is to decrease.
at approximately 16 months of age. Selected heifers Accuracy values range from 0-99%.
are retained for breeding and the balance marketed
at approximately 16 months weighing 415 kgs (230 kg As a rule, animals should be compared on EBVs
carcase weight and 8 mm fat depth) As some daughters regardless of accuracy. However, where two animals
are retained, maternal traits are also of importance. have similar EBVs the one with higher accuracy could be
the safer choice, assuming other factors are equal.
AngusPure Index ($) – Estimates the genetic
differences between animals in net profitability per cow For further information please contact NZ Angus
or TransTasman Angus Cattle Evaluation.
TACE EBVs (AVERAGE FOR 2019 BORN CALVES)
Dir Dtrs GL Birth 200 400 600 Mwt Milk SS DtC
+1.8 +2.1 -4.4 +4.2 +46 +84 +110 +95 +16 +1.9 -4.2
Cwt EMA Rib Rump RBY IMF Index Values
+61 +5.4 +0.1 -0.2 +0.4 +1.8 SR +$100 AP +$104 HDT +$102
ANGUS INDEX VALUE KEY SR - Self Replacing AP - AngusPure HDT - Heifer/Dairy Terminal
7