Page 8 - Tawanui, Aywon, Te Kupe Sale 2021 ebook

Self-Replacing Index ($) - Estimates genetic differences between animals genetic correlations with other recorded traits. Hence accuracy indicates the
in net profitability per cow joined for a self-replacing commercial herd, “confidence level” of the EBV. The higher the accuracy value the lower the
targeting the production of grass finished steers. Steers are assumed likelihood of change in the animal’s EBV as more information is analysed
marketed at 525 kg live weight (280 kg carcase weight and 10 mm fat for that animal or its relatives. Even though an EBV with a low accuracy may
depth) at 16 months of age. change in the future, it is still the best estimate of an animal’s genetic merit
AngusPure Index ($) – Estimates genetic differences between animals in for that trait. As more information becomes available, an EBV is just as likely
net profitability per cow joined for a self-replacing commercial Angus to increase in value, as it is to decrease.
herd, targeting the production of grass finished steers for the AngusPure Accuracy values range from 0-99%. The following guide is given for
programme. Steers are assumed marketed at 525 kg live weight (280 interpreting accuracy: See the Table below. As a rule, animals should be
kg carcase weight and 10 mm fat depth) at 18 months of age with a compared on EBVs regardless of accuracy. However, where two animals
significant premium paid for marbling. have similar EBVs the one with higher accuracy could be the safer choice,
Heifer/Dairy Terminal Index ($) – Estimates the genetic differences assuming other factors are equal. For further information please contact
between animals in net profitability per female joined in an example NZ Angus or TACE.
herd where all progeny are marketed. All progeny are marketed at ACCURACY
approximately 510 kg live weight (280 kg carcase weight and 7 mm fat RANGE INTERPRETATION
depth) at approximately 24 months of age. less than EBV should be considered as a preliminary estimate. It could change
Note that $Index values for individual animals are sensitive to the 50% substantially as more performance information becomes available.
assumptions used in the BreedObject analysis to calculate the selection Medium accuracy, usually based on the animal’s own records and
index. More information is available on the weightings used in the New 50-74% pedigree. Still subject to substantial changes with more information,
Zealand Angus Selection Indices. particularly when the performance of progeny are analysed.
ACCURACY 75-90% Medium - high accuracy and includes some progeny information.
Becoming a more reliable indicator of the animal’s value as a parent.
Accuracy (%) is based on the amount of performance information available more than High accuracy estimate of the animal’s true breeding value. It is
on the animal and its close relatives - particularly the number of progeny 90% unlikely that the EBV will change much with the addition of more
analysed. Accuracy is also based on the heritability of the trait and the progeny data.
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