How well EBVs describe the performance of progeny was part of a recent project examining bulls and their progeny involved in the Angus Sire Benchmarking programs cohorts 5,6 and 7. The project, which built on existing work examining earlier cohorts, found that EBVs provide an accurate prediction of the breeding value of sires.
For birth weight, the project found the difference between the average Birth Weight EBV of the highest and lowest 10 Birth Weight EBV sires in each cohort was on average 3.7 kg, across cohorts 5, 6 and 7. This equates to a predicted difference in the average birth weight of progeny between sire groups of 1.9 kg. The expected difference is only half the difference in the EBVs, as the sires only contribute to half of their progeny’s genetics.
When the average birth weight of the progeny from the highest and lowest 10 Birth Weight EBV sires was measured, the actual difference in birth weight was 1.5 kg, demonstrating the EBVs were accurately predicting the breeding value of sires for birth weight.
Check out the Lessons from the ASBP resources, available on the Angus Australia website for the other birth and fertility traits and the results from the earlier work examining cohorts 1, 2 and 3.