How useful are genomic tests for commercial cattle (or, Should I read the fine print?)

Abstract

Genomic tests are becoming widely available, initially for health conditions but now increasingly as predictors of production merit or value. The principle behind them is simple - take a tissue sample of each animal, send the sample(s) to the appropriate lab, and get back a report which will have some value or ranking of the individual(s) for some purpose. Current examples are tests of the merit of commercial Angus heifers (https://www.angusaustralia.com.au/breeding/animalselection/angus-heiferselect/) and tests of feedlot merit being trialled now. Such tests offer potential value for commercial producers and others in livestock value chains, but it is worth understanding the determinants of the utility of such tests, which are: a) The accuracy of the test - how well does it predict performance in the population? b) How much is it worth testing - what are the differences being predicted? c) What does it cost?