What is % Southdown?

% Southdown is used by Babydoll Sheep Breeders Australia (BSBA) to summarise the amount of Southdown genetics in the pedigrees of sheep in our Babydoll registry. We use the % of Southdown genetics in the pedigree to decide when a Babydoll sheep is eligible to be inspected for registration as Purebred Babydoll. This is one way that we manage quality for the BSBA Purebred Babydoll sheep.

The BSBA Babydoll breed is being developed using genetics from Southdowns, a heritage breed registered with Australian Stud Sheep Breeders Association (ASSBA). A sheep with 100% Southdown genetics should be able to trace its pedigree back to ancestors in the ASSBA Southdown registry. This includes most sheep now in the ASSBA Babydoll registry along with the Southdowns of various sizes and body shapes in the ASSBA Southdown registry.

Where a sheep has no proven Southdown genetics we call that 0% Southdown. This applies to other breeds sometimes used for introducing colour into our Babydoll breed or where sheep look like Babydolls but it is impossible to verify their pedigree. For sheep coming into the BSBA Babydoll registry from other registries, sometimes we allocate a % less than 100% for sheep that have been registered as purebred elsewhere because their extended pedigree does not support calling them 100%.

We calculate the % Southdown for a sheep by averaging the % Southdown for the parents. For example

• A lamb from a 0% Southdown parent and a 100% Southdown parent would be 50% Southdown genetics (same as Grade D or first cross in other systems)
• A lamb from a 50% Southdown parent and a 100% Southdown parent would be 75% Southdown genetics (same as Grade C or second cross)
• A lamb from a 75% Southdown parent and a 100% Southdown parent would be 87.5% Southdown genetics (same as Grade B or third cross)
• A lamb from a 87.5% Southdown parent and a 100% Southdown parent would be 93.75% Southdown genetics (same as Grade A or fourth cross)

In the BSBA registration system, once a sheep has a % of Southdown genetics in the pedigree over 93%, it is eligible for inspection for registration as a BSBA Purebred Babydoll. During the inspection they are checked for how well they meet the BSBA Babydoll breed standard. Not all sheep in our registry pass inspection, even if they have 100% Southdown genetics.

Read more about BSBA Purebred Babydolls