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The journey ahead: Diversity in Genetics

Climate change is with us. Fortunately, the set of bulls available to us have a diverse range of breeding attributes. A judicious selection of these bulls enable us to strengthen our herd against the ravages of climate change.

In the previous section "Join us on the journey" we try to formulate our breeding strategy based on the climate which we experience in the Karoo. We also examined the progress of our herd towards these objectives.

Nature can, however, not be cast in one single straight jacket. Our herd consists, therefore, of a variety of blood lines and breeding attributes. In order to progress along our overall strategy we use a variety of AI and own bulls on specific cows in the herd. Breedplan's app "Mating Predictor" is in this regard of great assistance to measure the outcome of every proposed mating, with the following as our objective:

Regardless of which bull we used, the outcome of each mating should meet the following criteria:

* Inbreeding coefficient should be less than 5% (this is non-negotionable);

* Calving Ease Direct (CED) en Calving Ease Maternal (CEM) should be in the top 20% of the SA 2018 crop);

* Mature Cow Weight (MCW) should be equal or less than 33 (in the lower 50%) and 400 day growth at 29 and more (in the top 30%);

* Fertility attributes SS (Scrotal Size) and DtC (Days to Calving) should be in the top 20%;

* Body condition: one would prefer bulls with EBV’s for EMA, Rib and Rump Fat as well as IMF in the top 10 to 20% of the SA 2018 crop, but this is not yet achievable due to a lack of data and breeding material; and

* In summary we strive towards economic indexes for both SBI and SPI which should be in the top 10%.

This exercise is repeated every year. One is always searching for more information on how Climate Change affects our own climate and cattle. At the same time one is looking for a diversity of genes in order to harness our cattle to cope with the changing climate.

The journey continues.

Make every mating count

Sires used in our seedstock operation

Jozette Gonasty PP, Zoetis Southern Africa Proven Bull of 2018

Prostock Hugo PP, is a full blood red Simmental bull bred in the USA.

Hugo is a homozygous polled bull which provides out-cross genes to our stud. In the USA Hugo is known for its calving ease and low birth weight and this has also been experienced on Doornbult. His EBV for birth weight is in the top 10 % of the 2018 SA crop and his EBV for calving ease in the top 25%.

Kwantum Profeet

He is known for calving ease (top 10% of the 2018  SA crop), low birth weight (top 10%) and high growth (EBV for 400 days in top 10%). He is considered as one of the first curve bender bulls of the breed. His MCW is, unfortunately, too high for our harsh environment.

Salerika Bravo BGP bull.


Bravo was a BGP bull since 2014. He brought strong growth genes (e.g. high EBV for 400 days) to our seedstock. It had, unfortunate, a low EBV for calving ease (CED) and a high EBV for mature cow weight (MCW) which needed to be managed properly in our herd.



Simberg Zolerz P

Zolerz P is a rare curve bender: EBV's for calving ease (high), birth weight (low), growth (high) and then a medium EBV for mature cow weight. Having Blinkbou Herz P as his sire, Zolerz excelled also in superior body condition traits. He brought excellent breeding results to our seedstock.

Breeding values

      About 70% of what one sees in an animal is due to its environment such as food, climate and management. The rest, 30%, is due to its genetic makeup. The Estimated Breeding Values (EBV’s) of specific traits or attributes depict an animal’s genetic potential to transfer such traits to its progeny.

 The EBV’s which we as Simmentaler breeders use are provided by Breedplan, an Australian company. Breedplan is a world leader in beef breeding and is continually upgrading its service based on intensive ongoing research.
      The confidence level (or accuracy level) of a specific EBV value of a trait of an animal is determined, inter alia, by the heritability of such a trait plus the data available on such an animal’s progeny. When one needs to choose between animals, the golden rules are:

      • Use the EBV’s of the various animals regarding one’s breeding goals in order to choose a group of animals with the highest potential.
      • Favour those animals with the highest EBV’s plus the respective accuracy levels.
      • Then make a last choice based on the outward appearance of the animals.

Economic indexes

      Economic indexes are compiled to give an indication of the economic value of the breeding potential of a specific animal. These indexes are for different farming systems, that is:
      TS - Terminal Sire Index
This index is applied to a commercial crossbred herd where no animals are kept for replacement or breeding purposes. The terminal sires are being mated to moderate weight Bos Indicus/British type cows. Calves are weaned at 7 months (at around 250 kg) and then fed extra rations for 120 days to be slaughtered at around 11 months and 430 kg steer live weight. Significant emphasis is placed on calving ease (23% for CED (calving ease direct)), 400 day weight (42%) and carcass yield (24%).
       SF-Feedlot Index
The Feedlot Index is aimed at a high fertility, self-replacing (keeping replacement and breeding progeny) pure bred herd. Significant emphasis is placed on calving ease (18% for CED) and calving ease maternal, CEM, (of the daughters) (17% for CEM), 400 day weight (19%) and carcass yield (14%). Mature cow weight (minus 12 % for MCW) is also taken into account  as a medium frame cow shows a higher fertility than a large frame cow.

  SG - Grass Fed Index
This SG index is aimed at a self-replacing pure bred herd. Calves are weaned at 7 months and then finished off on grass with little extra rations. Significant emphasis is placed on calving ease (15% for CED and 16% for CEM), 200 day weight (18%), days to calving (minus 21%)  which means that the less days there are to calving the more fertile is a herd , and carcass yield (13%).

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