Index Selection & Breeding Objective
Rather than trying to weigh up fleece weight, fibre diameter, body weight and possibly many other traits in your head and then apportioning the correct value to each when selecting sheep, it is possible to combine all measured traits and present them as one figure. This figure is known as an index. The breeding objective is what you want your breeding program to achieve and this is done through using an index.
In addition to making the job of selecting much easier, it is possible to place more emphasis on one particular trait over another when calculating the index. This way you can push your flock in the direction you want it to go much more easily. The system ranks animals on their capacity to reach your breeding objective as quickly as we possibly can.
Hazeldean's Breeding Objective
Since 2013 we have moved from the 7%+ index to the straight 7% index to redistribute the selection pressure from staple strength to increasing wool cut, lowering micron with a slight boost to live weight. Staple strength is not forgotten but is maintained to slightly improved.
Why is Hazeldean not using one of the standard MERINOSELECT indexes?
We have worked through a process where we applied the outcomes from the standard MERINOSELECT indexes (MP+, FP+ and DP+) and compared these to the previously used 7% indexes. Based on Hazeldean commercial sheep production and the last 5 year average wool and meat price the 7% index produces higher projected returns than the 7%+SS or the three standard indexes.
Given the large reduction in fibre diameter achieved by the stud over 20 years the index was fine tuned to place additional emphasis on other traits the stud wishes to emphasize. We also select for fertility, worm resistance, growth rate and carcase value.
It's exciting times for the stud with many of our sale rams trait leaders across the industry. With the introduction of full pedigree recording from the 2013 drop onwards - and the integration of genomic technologies (we're going to be busy) and our genetics unparalleled in improving your flocks profitability.
The gains made by the Hazeldean program are quantifiable, permanent and compound over time.
Our focus is on increasing the potential of Hazeldean Merinos to generate more profit for our clients.
We have achieved this goal but continue to push our program to deliver more. Hazeldean Merinos are proven to be the clear leader in dollar terms in on-farm bloodline comparison trials and wether trials, a client recently winning the largest wether trial in Australia, the Peter Westblade Memorial Challenge with all clients with sheep entered showing outstanding results.
Every year Hazeldean undertakes a large AI program with the most proven progeny tested sires thereby producing large lines of high performing rams sired by the most profitable rams in the industry.
Hazeldean Genetic Trend over the last 10 years. Hazeldean has far heavier fleeces than the average, that are also finer than the average. Click to view data.
Indexes are just a way of determining which animals most closely match your breeding objective by combining the most important economic factors into a single measure of economic merit that expresses the breeding objective.
Fibre Production Index
The Fibre Production (FP & FP+) indexes rank animals on their ability to produce merinos for a wool production operation.
The index is aimed at those producers whose majority of sheep income come from their wool clip. It is for self-replacing merino flocks who keep their wethers as part of their wool producing flock.
Merino Production Index
The Merino Production (MP & MP+) indexes rank animals on their ability to produce progeny for a fine wool operation that has significant surplus sheep sales.
The index is aimed at those producers whose sheep income is a balance of both wool and surplus sheep sales. It is for self-replacing merino flocks who do not keep their wethers to produce wool.
Dual Purpose Index
The Dual Purpose (DP & DP+) indexes rank animals on their ability to produce merinos for a dual purpose operation.
These indexes are aimed at those producers whose majority of sheep income comes from sheep sales. It is for self-replacing merino flocks that do not keep their wethers and also join a portion of their ewes to terminal sires for lamb production.
What is Micron Premium?
The micron premium tells you how much the price of wool increases if the fibre diameter decreases by one micron.
Genetic worth can be expressed in two different ways:
- EBV's (Estimated Breeding Value)
- ASBV's (Australia Sheep Breeding Values)
Both are an estimate of genetic worth for any particular trait.
What's the difference?
An ASBV is an estimate of the genetic worth of an animal for any measured trait. ASBV's can be thought of as a picture of the entire number of the animal's genes for any trait.
An ASBV is an estimate of the genetic influence an animal can have for any measured trait when used for breeding. ASBV's can be thought of as a picture of half of the animals genetic worth for any trait because in reality a ram (or ewe) will only contribute half of its genes to its progeny, the other half coming from the other parent.
So in effect ASBV's look at the worth of the total of an animals genes whereas ASBV's look only at the effect of those genes in the progeny. This is because the other parent has watered down by 1/2 the expression of the other parents genes.
Examples of using ASBV's
|ASBV||Clean Fleece Weight||Fibre Diameter|
Comparing the two rams, Ram 1 has an ASBV for clean fleece weight of +8%. That is, the progeny of Ram 1 are expected to be 7% superior (8.0 minus 1.0) for clean fleece weight (or have 8% heavier fleeces than the average), than the progeny of Ram 2 with an ASBV of 1% (which will be expected to have fleeces only 1% heavier than the average).
Similarly, Ram 1 has an ASBV for Fibre Diameter of -1.2micron. Ram 2 has an ASBV for Fibre Diameter of +0.8micron. The progeny of Ram 1 are expected to be 2microns finer (-1.2 minus 0.8) than the progeny of Ram 2, (that is, the progeny of Ram 1 are expected to be 1.2 microns finer than the average, while the progeny of Ram 2 are expected to be 0.8 micron stronger than the average).
Rreproduced with permission from the University of Melbourne's Mackinnon Project
Ram Select is a new tool developed by the sheep CRC - use the App to rank rams according to your specific needs and breeding objective based on their ASBV's
Let RamSelect do the hard calculations to identify the best rams for your flock.
RamSelect.com.au quickly searches all rams listed for sale and selects those that align with your specific breeding objective...read more