Genetics

Weekly genetics review: “EBVs cause your herd to go backwards” – some responses to observations during the year

Genetics editor Alastair Rayner, 12/10/2021

AS any professional tradesman will tell you, there is the correct way to use a tool, and there are wrong ways to use them.

When a tool is used for its designed purpose, the outcome can be measured through increased efficiency of labour, less waste or resources and time or simply creating the intended product.  Used incorrectly, tools can waste time, resources, damage the material in place or even cause injury or harm.

Fundamentally I think most people accept this premise.

Over the course of 2021, I have spent lots of time discussing with bull breeders and commercial producers the use of the tools at our disposal to create genetic improvement.

It seems that there are often extreme views about the tools at hand, let alone a strong understanding of the correct methods of use in seeking to achieve an outcome for a breeding objective.

Making selection decisions is not an easy process. There are a multitude of factors to consider, ranging from the cow base that producers must work with; the environment in which those cows will be exposed to; the target markets for the system. These factors often must be accounted for before considering the changes in traits that a producer wants to make to better shape their herd.

The challenge with genetic improvement lies in the complexity of genetics. On one level there is the heritability of traits, just how much will the traits of interest be impacted by genetics or by the environment.

Then there are the other interactions, the correlations between traits. Selecting for some traits versus others can have unintended consequences.

Looking at an animal really doesn’t answer the underlying questions around the genetics that animal will be able to pass onto progeny. How much of what is seen in the pens before the sale is the result of environmental impact or sale preparation?

The complexity of these interactions is difficult to appreciate, and where decisions around selection are being made, can’t really be given proper consideration from a visual assessment.

In the simplest definition, BreedPlan is a tool to assist in reducing the complexity by providing an indication of how a particular animal’s progeny are expected to perform, when compared to the average performance of progeny from other animals within the same year of birth and within the same breed.

BreedPlan uses an animal’s pedigree, and the actual production data recorded on traits for that animal, along with any production data from progeny that may have already been born, and performance data from any known relatives.

The calculations BreedPlan uses include the known correlations between traits, and the levels of heritability that are expected to be displayed. As a tool, BreedPlan offers Estimated Breeding Values (EBVs).

Divergent views

As with any tool, in any industry, what an individual does with that tool determines the outcome. From my observations during the year, there are producers who hold the opinion that “EBVs lead to herds going backwards” or to quote some recent reader comments, “long term use of EBVs will drive a herd to mediocrity.”

Personally, I think that is a pretty big call. Fundamentally herd improvement is something that can only happen with a clear objective.

Without that objective, it’s impossible to select the traits that will help a herd achieve what a breeder desires.  Saying that the desire is to have good cattle, is so vague as to be almost meaningless.

A more useful, and more practical definition of ‘good’ would be to have a herd of highly fertile breeding females, that are suited to the production environment, turning off the maximum number of cattle to market specifications each year. At the very least this gives some clarity for the producer, and some key areas that can be measured and managed.

From a selection perspective, this focus offers more guidance for producers. There is a framework to select animals for their physical suitability for breeding.

But it also offers a way to use tools such as BreedPlan in the correct manner. That is to look and compare animals from the same year of birth and within the same breed to rank those which are best suited to the program’s goals.

The accuracies of the EBVs offer some indication of how much is known about the animal – based on data already collected and analysed. The accuracy can make the comparisons more effective and take some uncertainty away in the decision process.

It’s when the tool is used incorrectly that outcomes become disappointing. While most producers would argue the biggest issues is selection for single traits or for a narrow range of traits, there is a larger issue.

That is quite simply having no real breeding objective in mind.  Without a clear direction, it’s very easy to fall into selecting for a single trait. Sometimes it’s the biggest figure; sometimes it’s a particular trait. Sometimes its traits that seem like they are important but have no actual benefit in the target market or for the production environment.

In these cases, it’s easy to see herds that have not made any real improvement over time.

It’s not the fault of the tool. BreedPlan will help find those animals that are likely to lead to increased growth, or marbling or fatness, or other traits. But if these traits are irrelevant to the actual operation, then is it the fault of BreedPlan or the person who employs the tool?

Ultimately as breeders operating a business, making progress is only possible with a focus to aim for. Having a focus offers a chance to make informed decisions, and to use the tools the industry has correctly to support the decisions.

If a breeder does not know what he or she is doing, and does not appreciate what the tool does, they can’t really blame anyone when it doesn’t work out.

With the sale season ending and joining underway, it’s probably a good time to stop and consider what the goals are for a breeding herd: What can be measured, and what needs to be changed to get the herd moving towards that goal.

When this is clear, the option to use tools like BreedPlan might be more rewarding for producers who are looking to achieve their goals more effectively and efficiently.

 

Alastair Rayner is the Principal of RaynerAg, an agricultural advisory service based in NSW.  RaynerAg is affiliated with BJA Stock & Station Agents.  He regularly lists and sell cattle for clients as well attending bull sales to support client purchases.  Alastair provides pre-sale selections and classifications for seedstock producers in NSW, Qld and Victoria.  He can be contacted here or through his website www.raynerag.com.au

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Comments

  1. GARY BULLER, 19/10/2021

    Spot on Brett.
    Snappy numbers in the boxes is absolutely no guarantee that you’ve got a good one!
    Look at the bull, then consider other selection options.

  2. Brett+McCamley, 13/10/2021

    As a lifelong beef producer, if you don’t understand what your short, medium, and long term breeding/production goals are, you probably aren’t going to understand any amount of information placed in front of you. I see potential buyers staring aimlessly at figures on pages without ever looking up to see if what they are bidding on is even structurally sound let alone reproduce. Education firstly for the Phenotype and all that the physical figures provide, education of the breeders philosophies’ and feeding regime, and maybe then after you have narrowed your selections down use any other data available. Remember that EBV is Estimated Breeding Values, not “Guaranteed” Breeding Values.

  3. Colin Hewitt, 13/10/2021

    As I read the above Alastair is saying it is dangerous to single
    trait select , I agree 100%. From my experience it is up to the
    Seed Stock producer to educate his clients ,how to use EBV’s,
    to suit their operation. For the average producer there are to
    many traits. I am a firm believer , that the most traits are as follows, on animals same age and feeding opportunities;
    200 day ( size of calf )
    600 day ( Final Growth , what we all get paid on depending on feed)
    Fat
    Muscle
    Days to calving ( one of the most important)
    Scrotal Size

  4. Paul+D.+Butler, 13/10/2021

    CLEAR OBJECTIVE = Maximum Continual Profit Per Unit of Land

    METHOD = Wholistic rather than reductionist decisions

    SELECTION TOOLS = Knowledge of profitability drivers, common sense and observation

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