ACCURACY

An accuracy value is published with each EBV, and is usually displayed as a percentage value immediately below the EBV to provide an indication of the reliability of the EBV in estimating the animal’s true Breeding Value (BV).

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.

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.

Accuracy values range from 0-99%. The following guide is given for interpreting accuracy:

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