TACE
Review of Angus Selection Indexes Andrew Byrne, Breed Development & Extension Manager
The review and updating of the selection indexes that are published in the TransTasman Angus Cattle Evaluation continues to progress. The Angus Breeding Index, Domestic Index, Heavy Grain Index and Heavy Grass Index, are economic indexes that balance the genetic merit of animals for individual traits to produce an overall “score” of an animal’s combined genetic value for the breeding objective defined by each index. The economic and production parameters that underpin the four selection indexes, along with the software that is used to calculate the index values, were updated in December 2020. However, based on feedback from members, the updates were removed to enable further consultation and development to be undertaken during 2021.
Angus Australia Members Have Their Say
Angus Australia members, and other interested parties, were invited to provide feedback on the selection indexes via an online survey and a series of focus group consultations conducted during April 2021. Feedback was sought on the importance that members place on selection indexes within their breeding enterprise, reactions to the updates that were made to the selection indexes in December 2020, suggested improvements to the manner in which selection indexes are calculated and displayed, and desired outcomes in the next five years in their Angus breeding programs.
Feedback from Online Survey
A total of 199 individuals completed and returned the survey to Angus Australia, with 98% of respondents being Angus Australia members, including a mix of seedstock producers, commercial producers, service providers, semen distributors and feedlotters. Respondents indicated that they placed importance on the selection indexes that are published within the TransTasman Angus Cattle Evaluation, with an average importance ranking across all respondents of 6.04 out of 9. 54% of respondents placed high importance on the selection indexes (i.e. importance ranking of 7 or greater). Of the individual selection indexes, the Angus Breeding Index was index of most relevance to respondents. However, all four selection indexes were deemed to be of high importance to at least some respondents, confirming that continued publication of all four selection indexes is warranted. Survey responses regarding the updates that were made to the selection indexes in December 2020 revealed two very distinct groups of respondents, with 33% of respondents indicating that they supported the updates (ranking of 7 or higher), and 43% of respondents indicating that they did not support the updates (ranking of 3 or lower).
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Support for the updates in December 2020 was linked closely to the importance that respondents placed on selection indexes, with respondents being most opposed to the selection indexes also being those members who placed less importance on the selection indexes. Respondents who did not support the updates also generally had smaller herd sizes than those who did support the updates. The existence of two distinct groups of respondents was further evident in the feedback regarding the specific aspects of the December 2020 updates. Respondents who supported the updates placed high importance on the use of the latest available software when calculating the selection indexes and on the updating the economic and production parameters that are modelled. Those respondents who did not support the updates placed less importance on these aspects. Similarly, respondents who supported the updates believed the correct type of animals ranked highly on the updated selection indexes, and the updated selection indexes better balanced female and steer traits, whereas those who didn’t support the updates tended to disagree with these statements.
