I’m often asked by prosective buyers of our Dorpers “How do I know what the numbers mean? F4? 3rd X ? etc”
Our Dorper herd is now almost all F4, or fourth cross. Basically the higher the number, the more pure the genetics of the breed you are crossing to.
So if you started with say a merino ewe and joined her with a 100% pure dorper (which means it would have been imported directly from Africa or bred with pure african imports – so very rare – though a F4 or higher ram would achieve a similar result) then that is a first cross dorper, or F1, and genetically its 50% dorper. If you then join that 50% dorper with a pure dorper ram, the offspring are second cross or F2, and it’s 75% dorper. The same again, and you have F3 and its 87.5% dorper. And the next time you get F4, and 93.75% dorper (so getting pretty pure).
In terms of the shedding capability of dorpers, we have found that the Dorper crosses will normally be fully shedding from the second cross, provided you’re using a good quality ram. This is obviously fairly important in order to carry through the dominant Dorper characteristics including shedding fleece and multiple births (twins are common)
As you’re probably aware, lamb prices are at an all time record high. Last week at the sales in northern NSW up to $500 was achieved for F4 dorper ewes – amazing!