Genetics: The big cow myth – measuring the economic impact

Beef Central, 21/08/2018


Prominent Angus seedstock breeder Harry Lawson* shares his views on cow size and ‘frame creep’. Despite the fact that eastern Australia is experiencing one of the worst droughts ever, beef producers are paying record prices for bulls with record Mature Cow Weight EBVs, and don’t seem to be connecting the dots, he says….


THERE is a worrying trend in the Angus breed that no one seems to be addressing: cow size and frame creep.

Despite the fact we are in the midst of one of the worst droughts ever, beef producers are paying record prices for bulls with record Mature Cow Weight EBVs and don’t seem to be connecting the dots.

No matter where you look, Angus cow size is on the upward move again. If we do a search, for example on the top 100 Heavy Grain Index bulls it’s hard to find a handful that are not extreme in MCW and/or birth weight and calving ease.

Look at the list of high-use bulls in the breed, look at the bulls being offered for sale in 2018, the information is right there, but somehow because beef prices have improved it seems to be ignored by beef producers.

Our recent Drought workshops in WA have highlighted the importance of understanding and doing the basic things in farming well – nutrition, pasture management, agronomy, animal health and genetics. It’s these tough years that put a lot of pressure on us financially and should force us to question how we do things. We need to look for better ways and systems going forward.

In terms of genetic improvement, our focus remains to build elite Angus genetics that not only lift on-farm profitability, but are accountable and profitable to all sectors of the supply chain.

Fertility and cow-efficiency will always be the backbone of any cow-calf operation. The big, lean, high-milk cows are always the first to fall over when feed resources are limited.

Our workshops focused on doing basic feed budgets and rations for each class of livestock. Put simply, feed (energy) requirements for cows are directly proportional to their bodyweight and when cows lactate their feed requirements go up by 40-45pc.

“The feed costs of running 700kg cows versus 500-550kg cows is over $100 per cow per year”

Lactational anoestrus (when cows are not cycling) is the most common cause of reproductive crashes in beef herds. The feed costs of running 700kg cows versus 500-550kg cows is over $100 per cow per year, so assuming cows are kept for five years on average, this is over $500 per breeder additional cost. However, the biggest cost is the risk of reproductive failure (or lengthy calving intervals for those that don’t control mate). Larger cows that have high milk potential and are lean increases the chance that they will fail to re-breed in time to maintain a 365-day calving interval.

It’s not just the feed costs or impact on stocking rates that beef producers need to consider in deciding what their optimum cow size will be – it’s the risk of getting a poor preg-test result (or delayed calving intervals).

The loss of income and genetic potential when this happens is astronomical. In tough years, particularly in autumn calving herds, pregnancy rates can drop from greater than 90pc pregnancy rate in normal years to less than 50pc in a drought.

This is not uncommon and can only be described as a generational financial disaster – less future income and less superior heifers coming into the herd. Forced sale of heifers causes a greater generational lag and lost opportunity to make cumulative production and genetic gains.

Our genetics industry is still way too focused on breeding genetically positive fat animals as a driver of fertility, when in fact cow size and milk are way more important traits in terms of economics.

For some reason the ‘fat fad’ has gained traction, yet most studs are ignoring (based on when you look at sire selection, genetic trends and the huge variance in MCW on bulls being sold Australia-wide) mature cow weight.

Fat is four times more energy-expensive to make than muscle tissue. Selection for genetically fat animals results in lower feed conversion and yield, so when times are good (or in a feedlot) genetically fat animals gain less and yield less.

Hence we continue to focus our selection on having animals with fast early growth, high carcase weight, high EMA and IMF and above average yield (below or around breed average fat).

Don’t assume our cows are small: after a good season last year in WA our mature cows weighed 640kg, which we think is big enough, and our challenge is to try and hold cow size and still improve growth.

If you consider that most studs (even the ones that claim to be focused on moderate-sized cows) are selling significant numbers of bulls with >100 on MCW, and in many cases with less growth than our bulls, then this is a serious issue, and shows the disconnect between the seedstock and commercial sectors.

Frame and cow size creep is a hard one to monitor, and the best way to try to manage it is to firstly ensure your bull supplier is submitting mature cow weights to Breedplan, and then to actually take careful notice of a bull’s MCW Breedplan EBV and not think your eye, or his actual sale weight, will give the same answer.


* Harry Lawson is the principal of Lawson’s Angus, based in Glenburn, VIC. The business has operations in Victoria, NSW, Queensland and Esperance, WA




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  1. Hugo Laborde, 25/07/2019

    As an agronomist now retired, I red a lot of paper in journals from Australia and NZ. I will visit both countries in the near future and I am very interested in viewing sub clover, cow calf operations and wheat growing, like my region in Argentina.
    Best wishes

  2. Mike Introvigne, 27/08/2018

    David, the simplicity you crave is depriving you of greater profits. Sensible crossbreeding is scientifically proven to increase the performance of calves via hybrid vigour. An even greater productivity gain is achieved from maternal hybrid vigour. All this can be achieved without compromising cow herd efficiency, its not rocket science but you do need to think outside the square otherwise profit driven beef production will pass you by.

  3. David C. Taylor, 27/08/2018

    I was carrying this argument back in 1972 and 73. I actually talked to beef producers of Aberdeen Angus and of large bred angus. I talked with men who were crossing with Hereford, Charolais, Simmental, and Gerts. In the end, though it was a gradual change, all had the same story. Herd size, numbers, were smaller. They could not carry as many cow/calf units per acre. Average cost of supplements and working the herd was up. Total weight carried across the scales was much less. Therefore, Christmas was not what it used to be. Some were already in the process of reverting back to pure angus, some were too far gone, then some were letting their ego get in the way. They liked being ghe guy with the big cows. This argument continues today, with good points from both sides i like the simplicity of purebred Angus. Don’t try to fix what’s not broken.

  4. Paul D. Butler, 26/08/2018

    Sorry Jon Wright…….I am not understanding your post……….especially about frame score and weight. Frame score is a measurement of structure and NOT body condition.

  5. Jon Wright, 23/08/2018

    The difficulty with this discussion is that it assumes all cattle convert the same. I would definitely prefer 1 bigger cow that converts well than 2 small cows that convert poorly.
    We should also consider the fact that fat cows weigh more hence eat more. The difference between a 600 kg frame 5 cow and a 600 kg frame 6 cow is fat. Fertility is important for a couple of months a year, why would we want a fat cow for the rest of the year. What a waste of feed. The myth of good doing cattle and fertility is so last century. Diligent selection for fertility by seedstock producers and providing a rising plain of nutrition to cows and heifers will beat body condition any day. No benefit in any form comes from a cow in body condition score 1. After that getting her fatter doesn’t increase fertility.

  6. Marg Killalea, 23/08/2018

    There certainly is some big BW and MCW numbers in current bull sale and semen catalogues.
    As commercial producers, we focus on a range of EBV’s (MCW under 100) and previously culled all extreme females.

  7. Gary Buller, 23/08/2018

    Harry makes some interesting points in relation to cow size and drought. However he seems to be saying that all large cows are lean, high milking, non functional, non-profit drivers. That doesn’t stand up, as large cows can be bred with positive to neutral fats, good milk supply and with the functionality and longevity to stay in the herd for 12-15 years.Those that blindly follow the EBV hype and listen and follow the breeders who are totally figure focussed, (‘multipliers’ I call them) find 5-6 years on, their cow herd has taken a dive. Fine boned, high figured wagyu lookalikes just don’t cut it for Angus breeders who are committed to breeding the type of Angus that made Angus the breed of choice. Consider how the Angus cow was considered the best maternal matron in the beef industry when breed average milk was +8 or+9 with do-ability, yet a decade on the average is +15. There lies one of the reasons why fertility takes a hit in dry times and why surviving drought has become a whole lot harder. Selecting sires like Incredible at +29 for milk and Intensity at +33 is undoing the functionality of the Angus female in any environment that is anything other than the land of plenty.
    Believing all that EBV’s purport to be, is fraught with danger. Are those growth figures really that high? Is that EMA for real? Will all my calves be born tiny and then produce explosive growth that will make the scales creak or will I have to find a backgrounder or feedlotter to finish them? My guess is there are a lot of commonsense beef breeders who aren’t convinced by EBV hype and that make judgements of their own that work in their environment and that just might be in a different space to those totally focussed on Breedplan.

  8. Mike Introvigne, 22/08/2018

    I can understand what harry is saying and agree with most of his points but Mathew also offers some insight into some of the cattle that are being bred from such ideology. Balanced females is the key, 600 to 700 kg cows aren’t too big if they are balanced with the right constitution. We weigh females and have our entire stud herd genomic tested with the American Simmental Assoc, arguably one of the most progressive breed societies in the world. So in answer to Steve’s question we have a Stayability EPD that does just that.

  9. Rob Mackenzie, 22/08/2018

    Join for 84 days every year. Weigh cows and weaners do percentages.

  10. Rob Mackenzie, 22/08/2018

    Well said Harry and Steve – There is science out there proving what these gentlemen are saying is true. In our own herd we have been weighing cow weaner and as a result the big cows aren’t pulling their weight in any season then throw in an 84 day joining period

  11. Steve Taylor, 22/08/2018

    Good article Harry,
    For every steer winning a feedlot trial there is a sibling female in our commercial environment struggling to survive and reproduce because of too much growth and too little fat.
    All of our genetic decisions have to be made at the cow/calf sector, when will we see an index for cow resilience and function?
    High time that embraced all sectors of production when we make these decisions.

  12. Paul D. Butler, 22/08/2018

    Sounds like Harry is smarter than the average angus breeder.

  13. Matthew Della Gola, 21/08/2018

    The biggest problem I can see coming in the beef industry is the fashionable fad that low birthweight and calving ease is somehow a magical saving grace. Not mature cow weight. Yes you must be conscious of it but breeding fine bone narrow pelviced pigmies because your concerned about a cow getting to big in its frame. I no what I would prefer. Atleast in a drought a 650 to 700kg cow is worth something to the farmer to send to the abattoir. Im pretty sure most abattoirs penalize cows once they start dressing under 200 to 230kg dressed weight. As long as your 400day weight and mature cow weight are close that’s good enough. The rest of your selection on your female regarding type and size can be culled visually. In my opinion seeing as I have nothing to gain through a self promoting article. Is that above breed average birth weights coupled with short gestation lengths along with visually selected features is a far more profitable trait to select for if you want longevity and strength in your female herd.

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