WHY RETAIN TEN YEAR OLD and OLDER COWS?

Team Dulverton has as one of its objectives, the provision of Sale Bulls to their commercial clientele capable of lasting at least three (3) and preferably four (4) breeding seasons. Rightly or wrongly, it is the team’s contention, that if a cow can still be functionally productive as a ten year old and older, then her resultant progeny do have a better chance of-

• breeding replacement heifers capable of breeding bulls with the ability to last three (3) preferably four (4) breeding seasons.
• breeding young bulls with sufficient longevity to last a minimum of three (3) preferably four (4) breeding season.

In the previous article in “Chaps Chatter” it was shown how dramatically the Sires contribution to the $cost of a pregnancy drops off if the Sire can last the three to four breeding seasons.

The Trait Stayability, defined as “The chance a heifer will remain in the herd as a productive cow until at least six years of age”, by the organisation Igenity Beef is now a trait selected for by Team Dulverton. The Igenity Beef Profile (IBP) data points to the fact that Sires with an IBP score in the top 25% for Stayability, Score 7, will sire daughters who will produce two more calves in their lifetimes than a Sire with an IBP score in the bottom 25%,  score 5, for Stayability.

THE OLDER MATRONS CONTRIBUTION TO THIS YEAR’S SALE DRAFT

There are thirteen (13) sons of the eighty one (81) catalogued who are from ten year old and older cows, they were ten or older at the time of calving their “U” calf. That’s a very creditable sixteen percent (16%) of the draft. Note these thirteen progeny have an average VALUE DETERMINING INDEX (VDI) of 62.9, range 56.5 to 69.5. The eighty one bulls in the draft have an average VDI of 61.7 and the twelve bulls born out of heifers have an average VDI of 64.9. Currently the team has set a target of a minimum VDI for The Sale draft of 60, not an average of 60 but each individual in the draft Scoring 60. There are only four of the thirteen sons of The Ten Plus Matrons who have scored less than 60 on that average of 62.9

Progress toward this target is definitely happening, the twelve sons in the draft from the two year olds average 64.9, not one individual registers below 60, the range being 60 to 71.5.

The Ten Year Old & Older Cows Sons  WOW. N = 13

Team Dulverton did use the Lot 2 son of Q108, Dulverton Unit U156 as a yearling over a set of “aged” cows. He was selected because he-

• Has a VDI of 69.5, oh so close to our required score of 70. It’s The Team’s intention to only use Sires with VDI Scores of 70+, this is still quite difficult as there aren’t all that many “Profile Sires” recorded with the IBP. Many of those that do record scores of 70+ aren’t Structurally Sound enough to warrant using
• Is out of a mighty old Stalwart in D. Dell G027, G027 was 12 yr old when she gave birth to U156. Interestingly G027’s “V” heifer by Renny Lea R511 registered a VDI of 70.5. Sheza Star. D. Dell G027 is so structurally sound herself, particularly udder shape and attachment plus teat shape and size.
• Is Structurally very, very sound, he is a Grade 7 with particularly good feet. The Q108’s exhibit our preferred pelvic shape and capacity, pin bones set wide and below the hip enabling the ideal “roll” from hip to pin so necessary to assist the foetus manoeuvre safely
  down the birth canal at parturition.

D. Unit U156 certainly isn’t “flavour of the month” with the two Breedplan published Indexes, he ranks in The Bottom nine percent (9%) of the breed.

Does this worry us? NO NO NO

t is imperative to understand that Breedplan is a Statistical Model, developed during the latter half of the 1980’s and early 1990’s. Objective Measurement was in its infancy and the trait list did not include traits relating to Longevity/Stayability, $cost of sire per pregnancy etc. The Breedplan Model has a problem coping with age, most cattle six years and over have downgraded “numbers” from those published for them as two year olds. Furthermore, The Model has problems accommodating homebred sires with little to no outside of herd linkage. Team Dulverton uses young sires bred in the herd such as Q108 because of their structural soundness, note of the six Q108 progeny in this sub set, three are Grade 7’s. Q108’s six progeny have an average VDI of 63.8, the thirteen bulls in the subset average 62.9 and the eighty one in the catalogue 61.7.

What has The Team Learned from this Set of Special Matrons?

Unfortunately The Team can’t speak “The Bovine Language”, pity because there are many facets of Maternal Production that these ‘Ole Matrons can share, Observe, Listen to what they have to say, perhaps they are trying to say

• Maternal productivity cannot be successfully measured from the performance of two or three progeny from an individual cow, particularly where an objective is to have that female produce
               1)Daughters capable of producing Bulls able to successfully breed for 3 and preferably 4 seasons
               2)Bulls capable of successfully breeding for 3 and preferably 4 seasons.
• Let Fertility be The Governor of Growth, Fertility is the most important Profit Driver in any Productivity driven Beef Herd.
  Each and everyone of these thirteen cows are moderate framed, and so their nutritional requirements to -:
               1)Maintain Body Function
               2)To have the necessary Energy to calve down in Winter
               3)To adequately Lactate, Not too much, not too little, but Just right.
               4)To “Cycle” and fall pregnant
  aren’t too demanding under “Normal Seasonal” grazing conditions
• Some selection pressure needs to be applied to that all important Trait Feed Efficience
• Don’t put undue selection pressure on Traits that will negatively impact on The Mighty Matrons ability to perform at a level to Optimise Productivity functions listed above. For example
               1)Selection over a long periods of time for Positive Fatness will result in Fat deposits around the ovary amongst heifers, which will most definitely impair  first Oestrous Conception rates.
               2)Fat deposits in the Udder will definitely result in both reduced daily milk production and reduced length in months of the lactation.
               3)Excessive “Internal” and subcutaneous Fat levels will reduce the ability of adequate muscle function at the time of birth which can lead to Dystokia.

The Bovus is telling Team Dulverton that Fat is a tricky Tissue to manage, not one of these thirteen cows has ever exhibited a propensity to carry excessive levels of Fat. All of them are a product of The Teams unashamed commitment to selecting for Neutral to slightly Negative Fatness.

The Team is totally committed to following the most appropriate pathway to achieving, The Goal of supplying clients with bulls capable of lasting a minimum of three and preferably four breeding seasons.
The Contribution of the retained Ten Year old and Older Cows plus the use of The Igenity Beef Profile Trait Stayability are essential in assisting achieve the said Target.