​
Australian Sheep Breeding Values (ASBVs) are a prediction of an animal’s genetic merit for a particular trait. They provide an estimate of how an animal’s progeny will perform by analysing both its physical traits and the genetic merit of its relatives.
ASBVs account for the environmental differences between years and between flocks, allowing animals from flocks across Australia to be benchmarked and compared to each other. Each ASBV indicates positive or negative deviation from the 1990 average for the trait. Traits can be individually weighted according to the genetic objectives of a ram breeder to form an index. The breeding committee of the Darkan RBC, with direction from a geneticist and Sheep Genetics Australia, developed the RBC50 index to maximise early growth, hogget clean fleece weight, c-site fat depth (for resilience), bare breech and fertility. Before this, we were using the standard merino Dual Purpose+ index to maximise growth and fleece weight.
​
The Darkan RBC left the AMS in 1989 due to differences in breeding objectives, and the desire to use new breeding techniques including the earliest incarnation of ASBVs in merinos – pedigree BLUP EBVs. Today we operate as a stand-alone breeding operation using cutting edge genetic tools such as Matesel, DNA testing, AI and ASBVs in addition to visual selection to distribute rams. While physical contributions have stopped, the co-operative ethos remains. Members are encouraged to attend our annual field day to class and cull rams, have their say and elect representatives to the breeding committee.
Matesel
Matesel was developed by Dr Brian Kinghorn and is facilitated by Sheep Genetics Australia with two aims: maximise genetic gain and limit in-breeding in sheep.
After the user submits a list of possible sires and dams, and sets mob size, inbreeding and genetic constraints; Matesel runs a trial and error style calculation to maximise a chosen index. Upon completion, a list of individual matings are reported including an estimate of the genetic result of the progeny. Our single sire matings are organised completely through Matesel.
Prior to the development of the RBC50 index, we aimed to maximise the DP+ index, while applying extra pressure to clean fleece weight and weaning weight. Matesel helps a breeder to select the best rams to mate with the best ewes in order to maximise a chosen index within The program maximises a chosen index by matching individual rams to individual ewes and assessing the projected genetic outcome of the progeny within inbreeding and mob size constraints
We use Matesel to select individual sires to mate with individual ewes in the top tier of our flock to maximise our breeding objectives. It is also very useful tool to model how outside sires might affect our flock before we choose to use their semen in an AI program.
We continue to breed sheep best suited to the mixed farming systems of WA
