Longevity – The Unmeasured Trait

Longevity – The Unmeasured Trait

Over the past twenty years there has been an unparalleled effort focused on measuring a host of traits within the seedstock industry. An important trait that for some reason has slipped under the radar is longevity.

What is Longevity in the Beef Industry

Put simply Longevity is all about living longer. In the beef herd longevity is about the bulls within the sire battery fulfilling a functional working life of at least four (4) years. Currently the average working life for Angus bulls in southern Australia is 2.3 years.                                                                 (cf. McKinnon report).

The Female

Longevity is a concept that applies to the female component of the beef herd as well. The female working life in the beef herd whether it be in a seedstock or commercial cow/calf herd needs to be ten eleven years. That is, the maiden heifer is joined at 13months, calves as a two year old and subsequently at an interval of every 12months. She is then removed from the herd when the calf she delivered as a ten year old is weaned.

The cow herd models developed at Shannon Vale for a group of our commercial cow/calf beef businesses indicate substantial female losses through the working life of the model (13/14 month maidens to ten and a half year olds). These losses are based only on fertility loss, dystokia loss, and misadventure. For example, in a three hundred head cow herd, joining seventy (70) maidens, only 20 cows will wean calves as ten and a half year olds assuming fertility, dystokia and misadventure being the only contributors to that loss.

In reality this seventy percent (70%) reduction in female numbers is likely to be greater when drop-outs for structural defects that impact on performance e.g. poor teat and udder conformation, poor doing ability, poor locomotion (feet, legs, walking ability) etc. are considered. Should these additional contributors, such as structure, poor doing ability etc. become too substantial then other significant issues arise. For example, more replacement females have to be found these replacements would need to come from the maiden heifer group.  A good rule of thumb in determining the maiden joining percentage is thirty to fifty percent, should more maidens than thirty to fifty percent have to be joined then problems result:-

                                             i.            Cash flow opportunities are eroded. That is, instead of having 50/70% of the heifer maidens to sell in that year, there may be only 30/50% to sell in that year.

                                           ii.            Should too many ‘tail end’ heifers be retained then calving issues will escalate. That is, there will be too many heifers having to be joined who weigh under 320kg. Remember our golden rule for maiden heifers, each individual needs to be 320kg when joined and 460kg at calving.

                                         iii.            High maiden heifer retention rates also mean some heifer’s with structural defects may have to be joined; these defects are therefore carried forward rather than nipped in the bud pre breeding opportunities.

Too high a heifer retention rate complicates the beef breeding business by adding to an already high etrition rate (pregnancy percentage, dystokia, misadventure) and reduces cash flow opportunities in that year. Note heifer pregnancy rates will be in the order of six to eight percent lower than that of mature cows, calf survival rate will also be lower. This results in fewer surplus pregnant females being available.

To reduce the female etrition rate by considering Longevity in the cow herd is a must. Selection for Longevity in the cow herd provides an opportunity to increase the dollar value generated by the cow herd in a number of ways. For example should only 40% replacements be needed to maintain the cow herd model in equilibrium then 30% of the maidens can be joined and sold as PTIC heifers at a greater rate than a cull heifer. N.B. these PTIC heifers should not be mated unless they can achieve a live body weight of 320kg at the time of joining. It wouldn’t be unreasonable to expect the 30% PTIC heifers would make $250- $300 more than the outright culls. This sale of the PTIC heifers would realize an additional $10,000 over and above the ‘cull heifer rate’.

In addition should the etrition rate be able to be reduced and the base herd cows run for one more year, that is select for cow Longevity then the opportunity exists in the 300 cow herd model to sell 15-20 PTIC prime of life cows (5 and 6 year olds) for in the order of double the structural culls and C.F.A rates. Such an activity provides an increase of $400 per cow or $6,000- $9,000 depending on whether 15 or 20 are sold out.

Reducing female etrition by selecting for Longevity/ stayability has many upsides including improving cash flow by in the order of $15,000 to $20,000 in a 300 cow herd. In addition selection for heifers with growth rates in the order of 0.8kg/day (birth weight included) at 13/14 months will mean the steer progeny produced from these heifers and cows will have growth rates commensurate with those necessary to optimize herd productivity and hence profitability.

The Sire

The sire battery for any commercial cow/calf operation is one of the most important and significant components and is a major input cost. Consider the following scenario for the 300 head cow herd joining 65-70 replacement heifers per year.

  • Assume the replacement heifers are joined to first year bulls (yearling or two year olds) at 3%. Number of bulls required equals two.
  • Assume the 300 cows are joined at 2%. Number of bulls required equals six.
  • Assume a replacement is required to cover misadventure. Number of bulls required equals one.
  • Total bull requirement equals nine at $5,500/bull.
  • Total bull budget is $49,500.

It is our goal at Shannon Vale to produce Dulverton Angus bulls with the ability to achieve a 4 year working life. The cost per calf attributed to the sire is therefore $30.50. As already mentioned the average working life for Angus bulls in southern Australia is 2.3 years, the cost per calf for the average working life bull is $57.30 an increase of $27.00 per calf attributed to the purchase price of the sire.

Working life of BullCost per calf attributable to Sire
4 years$30.50
3 years$42.50
2.3 years$57.30
2 years$68.75
1 year$183.30

If we can lift the Longevity, (functional working life) of the Dulverton bulls for our clients from average (2.3yrs) to 3 years, then this represents a saving of in the order of $5,000 per year for our clients. If we can increase this working life from 2.3 years to 4 years then the saving for our Dulverton client is $9,000. If it is assumed that this 300 cow herd joining 300 cows plus 65/70 replacement heifers will require 2.5 replacement sires per year (based on 4 years working life), then the yearly bull budget is in order of $13.750. Naturally it isn’t possible to find 2.5 replacements per year so the bull requirement is 2 bulls in year 1, 3 bulls is year 2; 2 bulls in year 3 and 3 bulls in year 4 and so on.

Commercial cow calf operator’s know only too well that bulls working lives are reduced by many factors and so misadventure, fighting, joining percentage, number of bulls per cow group etc. all contribute to reducing the functional working life of bulls. Longevity traits such as soundness of structure, libido, scrotal circumference, doing ability, survival etc. are the domain of the seedstock supplier/ bull breeders.

There is no doubt that soundness of structure is the most important trait to be considered when evaluating Longevity traits for bulls. The list of structural considerations is comprehensive and includes: feet, legs, joints, walking ability, shoulder and hock angles, sheath, scrotum. Doing ability indicators such as body capacity, natural thickness, chest floor, skin, and hair type.

A bulls ability to naturally mate with 50/60 cows in a breeding season really does depend so much on the list outlined above. For that bull to work for 4 breeding seasons will mean he must be above average for the list outlined and he will need luck on his side to “dodge death or reduced capacity by misadventure”.

It is really important that the bulls to be introduced into the commercial cow calf herd are sound, only nine bulls are required to produce the 340 offspring out of the 300 head cow herd joining 65/70 heifers. Unsound structural defective bulls can have a large multiplier effect very quickly. Longevity is a trait that has enormous consequences in the productivity of commercial cow/calf herds. Improving longevity by firstly recognizing it as an important trait will not only improve productivity but it will increase profitability initially by reducing input costs.

The combined increase in revenue in the 300 cow herd joining 65/70 replacement heifers is in the order of $25,000p.a; $16,000 of this coming from additional income via the sale of surplus PTIC heifers and the sale of 15 PTIC prime of life cows, plus a saving of $9,000 on the sire battery by increasing the working life of bulls from the correct average of 2.3 years to 4 years.

Theoretical?  Why sure. However, incremental improvement to profitability will happen once the trait – Longevity – is recognized, understood and implemented. It would be extremely bold to suggest that the $25,000 increase in profitability will happen in year one, it won’t, yet increases of that magnitude will result once these mentioned benchmarks are achieved.


Currently in Australia there is an unstoppable charge toward achieving the highest possible number for the long fed index. The fact that this charge has resulted in this number almost reaching $200 is testament to the fact that human behaviour is still all about the biggest and the most being the best. These excessive index values are achieved in the main by ‘stacking pedigrees’. The top 15 sires for long fed index value have an average in-breeding co-efficient of 6.13%. All but 2 of these 15 bulls are 5% or higher for inbreeding co-efficient . The three full brothers have an inbreeding co-efficient of 10%. In- breeding to this extent may well lead to reduced fertility and reduced survival. A reduction in these traits of paramount importance to longevity will reduce productivity and profitability in the beef enterprise.

Interestingly the two traits that benefit most, that is, exhibit highest rates of hybrid vigour in a cross-breeding system are survival and fertility. Cross- breeding is about mating unrelated to unrelated where as these high index performers are the result of in- breeding or mating closely related to closely related individuals. The concept of out-crossing within the purebred herd is important to help maintain two basic contributors to longevity- survival & fertility.

Selection based on dollar value indexes would be made a safer and perhaps therefore more useable concept were it to be predicated by the law of the optimum, which states the biggest and the most isn’t necessarily the best.

It is our contention that no dollar value system is complete unless it includes LONGEVITY. Fundamentally because improving LONGEVITY in the seedstock herds will result in that trait being improved in the commercial cow/calf herds.


For years we have recognized the importance of longevity as a trait to be included in our selection criteria. Primarily our seedstock business success depends up on repeat custom. It seems happy clients are those who:-

                                    i. Have no problems with their bulls mating with 50 cows for at least three preferably four joining seasons.

                                  ii. Have few if any problems calving heifers.

                                iii. Have progeny that hit market specs and make successful replacement breeders who breed on and endure the test of time.

LONGEVITY is therefore integral to the success of our business – bulls lasting four seasons, cows enduring the test of time and maiden heifers calving unassisted. All three issues raised above are about survival. Bulls must be able to survive the rigors of four breeding seasons, for the cow herd model to function productively, as many first calf heifers as possible must calve unassisted. Bull calves that are born assisted will have a greater propensity to throw:-

        i. Calves that may need assistance.

      ii. Heifers who when they calve may need assistance.

Likewise retained heifers that have been assisted all exhibit a greater tendency to produce progeny who will need assistance than those who were born naturally. Cows who endure the test of time and remain functionally efficient, that is , produce a live calf every year until they are eleven and raise that calf have survival built in. calf survival, birth to weaning is an all important LONGEIVTY trait our goal is to achieve 92% calves weaned to cows joined. Interestingly diseases such as pesti disease, Neospora Thyleria etc. are making this goal more and more difficult each year.

High fertility rates are essential if LONGEVITY is to be realised. For a cow to remain functionally efficient she must conceive and rear a calf each year. Cows who fail to deliver on either front are removed from the Dulverton herd.


The Cow Family

The cow family in the Dulverton herd exhibiting exceptional LONGEVITY is the Mandy family. Dulverton Mandy Q43 is still functioning in the herd. She is 18 years this spring and dam of LOT 74 in the sale.

Q43s first two calves were heifers:-

  • Dulverton Many S124 by Dulverton Quantum Leap Q16 an imported Summitcrest embryo.
  • Dulverton Mandy T102 by Dulverton Re-build R112

Both these cows are still functional in the herd they are 16 and 15 respectively this spring. Both S124 and T102 have calved every year since they were 2 year old. S124s’ ‘E’ calf E165 has sons in this year sale and her G calf G28 by SITZ  New Design 458N was used as a yearling in the stud and is being retained in the stud.

T102 is the dam of Y203 who is Dulverton Corkers C199 dam. Dulverton Corker C199 topped the Dulverton sale sire averages last year and is again represented in this year’s sale.

We will be displaying Q43 and her daughters S124 and T102, under the banner of the stayable stars at this year’s Northern Beef Week- June 17 2013 at Shannon Vale.

The Bulls

Over the years we have retained a number of homebred sires who have bred well for us. The two who have had the greatest impact in our herd are:-

  • Dulverton Re-build R112
  • Dulverton Uptake U91

Both sire’s were still working naturally as eleven year olds.

Dulverton Re-build R112 and Dulverton Uptake U91 were both structurally correct; bulls can’t work naturally at 1100kg unless they are as sound as a bell. Both bulls have a host of daughters still functional in the herd.  Dulverton Annie W163 the dam of Dulverton Blaster B111 is by Dulverton Re-build R112. Dulverton Blaster B111 will have 7 sons in this years sale.  Dulverton Re-build R112 is the sire of the dam of Dulverton Eruption E126 who has 6 sons in this year’s sale.

Dulverton Uptake U91 sired Mundoo Freestate by natural service as a ten year old. This bull sold to Ireland Angus for $30,000. Dulverton Uptake U91 has weaners roaming the pastures at Shannon Vale, he sired them naturally as an eleven year old.

Dick Whale has Dulverton Uptake U91 semen for sale at $35.00 per dose. He is a structure and longevity improver.

We believe in LONGEVITY it makes sense that if the sire and dams of progeny we offer for sale have ‘stood in the test of time’ and jumped through our fertility prescribed ‘hoops’ then that progeny has a stand up start in fulfilling the commercial cow calf operators requirements for stayability, productivity and profitability.

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