Excitement over New Angus Selection Indexes

An index built on a model that is a good representation of your production system is a valuable tool.

Breed Indexes are a sophisticated system of combining multiple EBVs with different emphasis to derive dollar values that indicate profitability per calf throughout the supply chain. The complex models that they are built on are intended to represent different production systems. An index built on a model that is a good representation of your production system is a valuable tool.

Unsurprisingly, it’s hard to please everyone when we all have our own breeding objectives. For many years I’ve felt that the Angus indexes are too deficient to be of use to our family’s commercial enterprise. My major beef (ahem) has always been the lack of pressure on the endless increase in mature cow weight (MCW).

I’m not alone in being concerned about increasing mature cow weight. It’s been discussed for years amongst Angus breeders and a presentation at the Angus Australia Conference in 2019 brought the message home in no uncertain terms. Prof. Dorian Garrick from Massey University told us that a 2017 female costs US$57 more to feed than her 1980 equiv. (US data). “So collectively I would say the cow calf operator, the genetic change that has occurred since 1980 has not been what I would consider to be improvement”.

“So collectively I would say the cow calf operator, the genetic change that has occurred since 1980 has not been what I would consider to be improvement,”
Prof. Dorian Garrick.
Massey University

New Indexes address MCW

We learned in the Angus Connect Spring 2020 online presentation about the upcoming enhancements to TACE including the release of new indexes. The major change is the increased emphasis on maternal traits Milk and MCW. Notably, the penalty to the index score from MCW has increased from 4% to 17%.

The new trait mix for the ABI in 2021
The new trait mix for the ABI in 2021

All 4 indexes are modelled on self replacing herds and have been updated similarly.

The new indexes were some years in the making with input from a member survey, member feedback (going back to 2014), comprehensive review by the Genetic Evaluation Consultative Committee, and peer review by the experts at ABRI. They were launched in mid-December only to be pulled a week later because a number of Angus seedstock breeders didn’t like what it did to their cattle’s index values.

Impact of the changes to Black Star Angus?

We were pleasantly surprised! We’ve been deliberatly keeping a lid on MCW for years. Our preference is to have both 400D and MCW close to +100. Our breeding objective was VERY aligned to the new indexes for the week that they were live as a quick review of our 2020 calves demonstrated:

  • 12% of our calves are in top 1% (percentile band) for the new ABI
  • 37% in the top 5%
  • 60% in the top 10%

I’m happy to say that the new indexes are now VERY relevant to my family’s breeding objective and I plan to use them to evaluate genetic progress in dollar terms in the coming years. I’m hoping they provide a useful tool to evaluate the rate of genetic gain we achieve with the commercial heifer genomics project we are participating in over the next 6 years.

What happens to the new indexes now?

Changing to the new indexes is inevitable. They represent the best science and latest modelling and better represent the needs of the users they were intended for: commercial producers. Expect to see them re-emerge in the next 12 months. For now, commercial users that utilise the current indexes should continue to do so – just take a red pen to any sires with MCW over +112 (the heaviest 25% percentile band).

Are breeding indexes right for your enterprise?

It’s important to have a good understanding about what any index represents. A fact missed by many commercial producers is that they evaluate the profitability for all participants in the supply chain – not just the breeder. You may be sharing the value with backgrounders, feedlotters, finishers and processors. A breeders whose turn off is at the kill stage enjoys more of the value (indicated in the index) than a breeder who sells calves as weaners.

The other aspect sometimes missed by commercial producers is that animals with a similar index score can achieve it with very high score in a some traits while leaving other traits below your breeding objective. For example, consider these two very different bulls with the same ABI of $147:

  • Bull A – 400D: +110; IMF: +1.5.
  • Bull B – 400D: +86; IMF: +3.8

This variation is neither right nor wrong – just a feature of an index that combines many traits. This is also a fairly extreme example.

Many breeders simply use indexes as the first filter of any long list of bulls under consideration. They then follow this with a review of individual traits and other selection criteria such as structure and pedigree. There’s nothing wrong with this approach either as long as the index is fairly relevant to their breeding objectives.

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