Many breeders worry that during a drought they will get lower Sheep Genetics ASBVs as their animals have lower weights. This is not the case. OVIS analyses animals within contemporary groups; that is, animals that have had an equal opportunity to perform. It is not the raw weight of an animal that is important, but rather how that animal has performed relative to the rest of its peers in the contemporary group. Animals are only ever compared to other animals within a contemporary group.
Once sub-grouped out of a contemporary group, they will only be compared to the performance of other animals within that sub group for subsequent measurements. It is how they perform relative to the average of the contemporary group and any subsequent sub-groups that is important. This is the reason it is important to have more than one sire represented in a contemporary group so that genetic merit can be separated from environmental effects. It is also essential that there is sire linkage between contemporary groups again so that environmental effects can be separated from genetic merit.
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