Weekly genetics review: Setting realistic targets for genetic improvement

Genetics editor Alastair Rayner, 27/08/2019

HOW realistic are most producers’ genetic improvement aspirations?

This is a question that is often overlooked in the focus on choosing a new herd sire.  According to Meat & Livestock Australia’s genetics program manager Caris Jones, there are many producers who may be setting unrealistic expectations on their new sires.

Speaking at the MLA Livestock Advisor Update in Sydney last week, Ms Jones highlighted the importance of using on-farm benchmark data to frame the genetic performance that is realistic for individual herds.

Illustrating this position, she described a producer who aimed to increase turnoff weights at 400 days by 40kg, while maintaining fatness and other traits for the preferred target market. A review of the EBVs highlighted a range of bulls that would offer the genetic potential to meet these outcomes.

Without knowing the performance of the herd in question, finding a sire that would actually help achieve this goal might be actually unrealistic. The key message from Caris Jones was that without knowing where your production is actually at, making the right genetic choices to meet breeding objectives can be extremely difficult.

While this is a busy slide, it captures an example presented by Caris Jones for a producer aiming to reducing turnoff age by 30 days. Current average = 350kg @ 15 months which means they wanted 350kg @14 months. If that producer was middle of the road genetically (50pc decile) the current 400 day EBV for Angus is +80. Add the additional growth, 30kg and this comes to +110. This exceeds the values on the reference table – in other words, its genetically unrealistic!

It is important not to overlook this message when developing a strategy for purchasing new bulls. Many producers who seek advice from myself and other consultants, have not always spent time realistically assessing their herd’s needs, or have a true picture of their current performance.

In reality, selection should be informed by herd performance data, and business data such as performance benchmarks. Extracting data from benchmarks and feedback does allow more effective selection decisions.

I would recommend producers spend time measuring their internal herd performance in several key areas. These include:

  • Fertility – conception per 100 cows (joined)
  • Calving rate – per 100 cows (joined)
  • Weaning rate – per 100 cows (joined)

Obtaining objective data depends on consistently measuring these traits over a number of years. This will provide an indication of the direction of a herd and will highlight areas that offer scope for improvement.

It is important to stress that the data has to be measured against the cows that have been joined, particularly in recording calving data and weaning rate.

There have been occasions where producers record a high calving percentage by measuring calves as a percentage of the cows pregnancy tested in calf. By not including the empty cows, the data they recorded was skewed, and the opportunity to correct and improve overall herd production was delayed.  Being honest about data is the only way that improvement programs can be correctly started for any herd.

Growth and weight at turn-off is a key area to measure. Many producers focus on growth traits as part of their bull selection. However, selection for growth needs to be based around needs within the herd. Again, I recommend producers consider key areas to benchmark that include:

  • Weight & age at weaning
  • Weight and age at turn off
  • Compliance with market specifications

There is a range of other measurements that could be included when determining the need to select for growth. However I often find these three areas highlight the major contributors to herd performance for most commercial herds.

As a benchmark for industry performance, it’s not uncommon to use a measure of total weight turned off per cow joined.

In 2018 MLA produced the Agri Benchmark results that identified Australian production in this area ranged from low levels of production (97kg liveweight per cow) in northern systems to 341kg liveweight per cow in southern systems (click here to view report).

The scope for improvement is therefore relatively large. However, knowing where a herd sits within this range will determine which genetic traits will offer the most significant improvements. Low turnoff weights per cow joined could potentially be addressed not only through genetic selection, but also with a focus on management of cow herds and addressing critical issues such as nutrition.

Being realistic about the opportunity for genetic selection to influence a herd not only requires appreciation of current herd performance – it also requires a degree of patience for the influence of new sires to be expressed throughout a herd.

In most commercial herds, what this year’s sire team contributes won’t actually be seen in the herd for a minimum of four years, and in some cases may take up to eight years.

The rate of genetic change within a herd is driven by producers’ intensity of selection, along with the accuracy of the genetic information they have at hand.

With this in mind, producers who have a clearer understanding of their levels of production and their profit drivers are more likely to have greater intensity in selection, and use sires that realistically can offer improvements.


Alastair Rayner

Genetics editor Alastair Rayner is the Principal of RaynerAg, an agricultural advisory service based in NSW.  He regularly attends bull sales to support client purchases and undertakes pre sale selections and classifications.  He can be contacted here or through his website













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  1. Jill Coghlan, 26/09/2019

    A very good article Alistair. Good that you’ve addressed the importance of nutrition and also understanding where your herds at.

  2. Richard Golden, 28/08/2019

    Pleasing to see the importance of using cows joined as the starting point for assessing fertility.
    Re weaning rate it is easy to miss that if the calf is weaned in May 2019 it was conceived in 2017.
    We recognise the importance of EBVs to guide bull selection with one very strong caution; % accuracy has to be very high if major reliance is placed on the figure/s.
    Our experience is that many? most? bull’s data is low enough in accuracy as to represent little better than a coin toss.

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