Angus Breeding Indexes.

Domestic index (DOM), Heavy Grain Index (GRN) and Grass Fed Index (GRS) 

EBV’s are a bit of a mine field for commercial producers.  With 17 individual main EBV’s and 4 indexes it’s no wonder that confusion reigns. 

First thing I would say is that EBV’s are a tool and are no substitute for visual appraisal.  In addition it is important to know which EBV’s are objective (actually measured) and which are subjective (in the eye of the beholder).

Indexes are another story….. 

Indexes combine a range of objective and subjective measurements into a single dollar figure.  The magic bullet number, so to speak.  They are a complex issue and the scientists behind the figures, in my opinion, need a review on how these figures actually translate in large scale herds and what impact they place when in a breeding and commercial environment.  Every production system is different, no farm is the same.

You will notice we don’t include indexes in our catalogue summary sheet for the sale bulls. This is because I don’t believe in a one number fits all type scenario.  Do these indexes compare a farmer who gets 400 mm annual rainfall on granite country that also has a fine wool sheep operation with a farmer who get 900 mm on basalt country and specialises in angus cattle only.  No they don’t. 

I strongly believe that EBV’s add some value as long as you know which ones have a strong tie to the needs of the profitability of your individual beef business.  Indexes don’t and are a trap for the unwary.

The EBV’s that I consider to be the most objective (if measured properly,) are:

  • Gestation length – based on known A.I. or joining dates
  • Birth Weight – actually weighed within 24 hours of birth ( breeders are not compelled to collect birth weights – if they don’t it is generated back from older weights taken and submitted)
  • 200, 400 and 600 day weight – actually weighed at those average ages
  • Mature Cow Weight – weighed at the same time calves are weaned and weighed for 200 day weight
  • Scrotal size – measured at semen testing
  • EMA – scanned at 600 days
  • Fat – rib and rump – scanned at 600 days
  • IMF – scanned at 600 days

To keep it simple I think there are a few traps that need to be avoided.

  • If you chase high growth numbers by themselves you will end up with high birth weights as well as high mature cow weights.  Your cow herd will become large framed and high maintenance.  This will lead to lower fertility when the season or conditions get a bit tough.  The trick therefore is to get as much growth as you can whilst maintaining a Mature Cow Weight (MCW) that is moderate ie. 80 to 95 roughly and a moderate birth weight ie. EBV under 6.  Positive fat is also important in the equation.  The result being a moderate, fleshy, easy doing cow herd that is fertile, calves easily and gives progeny that still powers on some weight.
  • If you chase marbling you will end up with cows that are, I guess, wagyu like.  Harder doing, angular and, in the case of angus cows bred this way, less fertile.  Our experience with the years of owning our own branded beef product showed us that Angus cattle marble adequately anyway.  Soft easy doing angus that are moderate and fleshy provided us with the juiciest tenderest eating experience.  Our product marbled scored predominately 3 and 4 on the MSA grading at 16 to 18 months of age at a carcase weight of 330 kgs.  So be careful of chasing marbling.

So this is what my perfect animal would look like in figures.  Short gestation, moderate birth, above average growth, average or below for mature cow weight, heavy carcase, large eye muscle area and positive rib and rump fat.

Indexes provide an indication of what it is that the specific market demands and what sort of animal they require. It’s up to the individual breeder to balance out the traits they require for profitability and sustainability within their herd on their particular farm.

I hope that makes sense and has at least given some food for thought.

Here are links to Breedplan and Angus Australia websites with explanations.


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