New software for Docility EBVs

Enhancement 3 – New Software for Docility EBVs

The software used to calculate Docility EBVs has been updated, resulting in the publication of Docility EBVs for more animals.

Docility EBVs are calculated within a separate, single trait analysis within the TransTasman Angus cattle evaluation. Previously animals were only included in the docility analysis if they had been scored for docility, or had progeny or grand-progeny scored for docility. New software will be implemented whereby all animals from the main-multi trait component of the TransTasman Angus Cattle Evaluation will be included in the docility analysis, resulting in the publication of Docility EBVs for a greater number of animals. While all animals from the main multi-trait component of the TransTasman Angus Cattle Evaluation will now be included in the docility analysis, similar to other EBVs, Docility EBVs will only be published if they meet the minimum accuracy threshold of 25%.

Figure 4 – More than 90% of animals will now have a Docility EBV published in the TransTasman Angus Cattle Evaluation

> Main impacts

· Docility EBVs for more animals: More than 90% of animals will now have a Docility EBV published. Previously, Docility EBVs were published for approximately 25% of animals.

· Docility EBVs published for animals without docility

scores: Animals may now have Docility EBVs published despite having never been scored for docility, or having being bred in a herd that has never collected docility scores. The EBVs published for these animals will be calculated from the docility scores collected on relatives in other herds, subject to the EBV meeting the minimum accuracy threshold. · New Breed Average EBV: The breed average EBV for Docility will now be approximately +20. The increase from the current breed average EBV of +7 is due to the inclusion of more animals in the docility analysis, along with the implementation of a base adjustment aiming to minimise the number of animals with a negative Docility EBV value. · Changes to Docility EBVs: While minimal change in the ranking of animals is expected, the implementation of a base adjustment will result in an increase in the magnitude of the Docility EBV that is published for most animals. In circumstances where the ranking of some individual animals has also changed for docility, the change is due to the inclusion of more complete pedigree information in the docility analysis for these animals, better linking the animals to their relatives.