Compare to the level of genetic merit within the current population
Meat & Livestock Australia April 8, 2024
Comparing against the current levels of genetic merit allows you to understand where an animal ranks within the evaluated population. BREEDPLAN uses the calving drop born two years prior the current year to define the current level of genetic merit in the evaluated population (e.g. in 2023, this would be the 2021 drop calves). This is because rising two year old animals have had an opportunity to be performance recorded for the majority of traits and many of the young animals available for sale will belong to this cohort.
You can use the concepts explained below to benchmark the genetics of your current bull team. This allows you to evaluate each bull in your team and identify whether bulls that you may be considering for purchase are an improvement over those you already own.
Compare with breed average
Comparing each EBV against the breed average allows you to quickly identify whether the animal is above or below the average genetic level for each trait:
Consider the demonstration animal above.
- It’s 400 Day Weight EBV is +52kg
- The breed average 400 Day Weight EBV is +35kg
- 52kg – 35kg = 17kg
Therefore, the demonstration animal has genetics that are 17 kg heavier at 400 days compared with the average genetic level of the current population
Compare with percentile bands
1. The Percentile Bands Table
Comparing each EBV against the percentile bands allows you to identify exactly where an animal ranks within the current genetic level of the population for each trait. You can do this using either the Percentile Bands Table.
The Percentile Bands Table shows the percentiles for each trait.
To use:
- First find the column that corresponds to the trait you are interested in. In this example, 400 Day Weight.
- Next, move down the relevant EBV column until you find the number range that contains the EBV of the animal you are examining. In this case, the animal we were looking at had a 400 Day Weight EBV of +52 kg, so we are looking for a value of +52 (or less).
- Once you have found the relevant value, follow the row along to the left to find the corresponding percentile. In this case, an animal with a 400 Day Weight EBV of +52 kg is in the Top 5% of the population for growth at 400 days.
2. EBV Percentile Graph
The EBV Percentile Graph provides a visual representation of where an animal’s EBVs rank within the population for each trait.
The 400 Day Weight EBV of the animal we were looking at is +52 kg. The EBV Percentile Graph shows us that this bull ranks in the Top 5% of the population for growth at 400 days.
Importantly, it is not always desirable to rank highly in the percentiles for all traits (e.g. between 0-50th percentiles on right hand side of the graph). Instead, optimum EBVs will depend on your breeding objectives (see Module 2 – Breeding Objectives). For example, a higher percentile for Mature Cow Weight EBVs indicates heavier mature cow weight. This may not be desirable for those trying to moderate mature cow weight in their herds.