Sandra Taylor

Breeding indexes are offered as a simple tool to help farmers select rams, but stud breeder Mark Stevenson believes they have the potential to take farmers down the wrong genetic pathway.

Mark, whose family has been breeding fine wool genetics since 1903, believes indexes over-simplify trait selection and could result in farmers inadvertently breeding against traits they are striving to improve, or vice versa.

“When you simplify something that is quite complex you can end up shooting at the wrong target.”

Indexes roll a number of traits into one single package and Mark believes in some cases the traits within the index can be counter-productive to what the individual farmer is trying to achieve in his or her operation. Increasing reproductive performance, for example, could result in a drop in survivability and growth rate.

‘The commercial client should be in partnership with their stud breeder, because as stud breeders, our success depends on that long-term relationship.’

“Beef + Lamb Genetics (BLG) has developed a maternal and terminal index in which they say the bigger number means a better ram.

“The sole focus BLG place on these indexes does farmers a disservice by reflecting the perfectly balanced, average animal across all farms and all regions, where in reality farm environments and systems vary enormously.”

The maternal index encompasses a lot of traits, but each farm will have a different weighting on each of those traits.

Many farmers may not want to increase their scanning percentage but do want to increase survivability and growth rates, yet the index does not allow them to tease out these individual traits.

Two rams can have the same indexes but within those, the traits can vary widely.

Mark recommends farmers look at the traits that are important to them and select the breeding values (BVs) accordingly.

Similarly, BLG’s terminal index includes three broad trait areas, but Mark believes that for most dryland commercial breeders, the two that are most important are growth rates and weaning weights, which are the profit drivers.

While BVs are important in selecting rams, Mark believes they are just part of the toolbox which includes stockmanship and quantitative data.

He urges commercial farmers to ask their stud breeders for advice when it comes to ram selection, as ram breeders are looking at rams every day and will know which are the best fit for their client’s farm environment.

“The commercial client should be in partnership with their stud breeder, because as stud breeders, our success depends on that long-term relationship.”

While Mark was brought up learning how to assess stock, he sees a real knowledge gap in many of his contemporaries and younger farmers.

Very little stock judging is on offer and very few people are teaching visual assessment, particularly in rams.
This means buyers often have to default to the numbers as they don’t have the skills to visually assess animals.

Mark says BVs, visual assessment and performance data are all part of the genetic toolbox and it is a matter of making the most of the tools available and using the knowledge and skills of stud breeders to select the right ram for the job.


Country-Wide asked Abacus Bio consultant Sharl Liebergreen to comment:

Mark is right. Indexes are simple, but there is a very good reason for that. The genetic knowledge available in (for example) the Sheep Improvement Ltd (SIL) database, is immense and leads to more profit onfarm.

Having detailed conversations with farmers about breeding values and heritability, is a waste of time. Their eyes glaze over very quickly. Having the same conversation with breeders is a different story. They love the detail, even if they don’t understand it. But all farmers have made the investment in the SIL genetic engine with their levy dollars, so delivering genetic information in a form which is digestible, is appropriate. That’s their return on investment for funding SIL.

Mark is saying is that there is a lot of data underneath indexes which can indicate significant differences in rams, i.e: two rams with the same index value can have very different types of genetic potential. And he is right. That’s why SIL also produces sub-indexes, and even the many breeding values that make up the indexes and sub-indexes.

So, farmers have access to very deep levels of information, should they want it and SIL makes farmers aware of it. The reality though is that the average farmer doesn’t ask for it (because he/she does not know where it is and how to interpret it, but that will change). What he/she wants to know is:

  • Am I getting my breeders best rams?
  • Am I paying too much?
    The reality is that many farmers do not view rams and bulls as an investment. They view them as a cost (or at least they have been). What they should be asking is:
  • Am I buying my rams from the right breeder i.e. are our breeding objectives aligned
  • What should I pay?

Mark also reminds BLG/SIL that their message “the bigger the number, the better the ram” appears to forget that rams also need to be structurally sound and functional. No point in having elite genetics if they can’t walk and mate.

And he’s correct. But, SIL have never suggested they provide information about feet or conformation. They are about objective genetic performance and I believe they have always been pretty transparent about that. Structure, function, feet, conformation, is left up to the breeder.

It’s unfortunate to see comments about a weaning weight measurement being a profit driver but breeding values and indexes less so. The reality is that the genetic evaluation is all about economics. It is reset every five years and makes sure that the product farmers produce, matches what our markets are looking for, and we maximise the opportunity to sell our product for the highest possible return.

Indexes are an indication of a ram’s ability to create profit. The higher the index, the more profit the ram could produce (together with sound management, feeding, animal health, etc) relative to other rams.

So, I agree with Mark. But farmers are asking for more detailed information about the rams they are buying and how that can help them make more money. Indexes are good indicators of profit, so it makes sense to talk to farmers about them. Ultimately, they have paid for the information.