MEASURES OF DIVERSITY
Breeders are encouraged to be familiar with common measures of genetic diversity within pedigrees, and to use pedigree software that can calculate them for test matings. No specific software is recommended, but breeders should be aware that there is free online software available. When choosing breeding combinations of stud and bitch, the following criteria are recommended:
An 8 generation Coefficient of Inbreeding (COI) at or below 6.25%
A 3-generation pedigree with 14/14 unique ancestors such that the ancestor loss coefficient = 1.0. This means that in a 3 generation pedigree of the type that has been traditionally available to breeders via the ANKC, all 14 ancestors should be different, and there should be no double ups.
A 4-generation pedigree should contain at least 27/30 unique ancestors such that the ancestor loss coefficient is at least 0.9
Breeding for a low COI is a strategy to maintain genetic diversity, and to keep overt genetic disease low in the population. A low COI cannot eliminate diseases that are already present in the breed. Unfortunately most diseases cannot be eliminated without substantial loss of genetic diversity. Breeding strategies that prioritise the elimination of a single disease may have the unintended consequence of making the health of the population worse via genetic drift and loss of diversity.
The Finnish Lapphund breed does have an open stud book, but new breed intake dogs are infrequent and they are not necessarily widely used at stud. Consequently, the risk of genetic diversity loss for the Finnish Lapphund is similar to any other closed-stud-book breed. Studies have found the side effects of inbreeding start to manifest where the COI exceeds 10%. The phenomenon of ‘inbreeding depression” includes reproductive problems, pup mortality, litter malformations, greater susceptibility to infection, atopy and autoimmune diseases. The higher the COI is in the breed, the faster will be the loss of genetic diversity for the whole breed over time.
Breeders should be aware that the COI that we are able to calculate with pedigree data assumes that the original breed foundation dogs were unrelated. This is often not the case. Studies have found that the ‘true’ COI in almost all pedigree breeds is higher than an 8 generation pedigree would suggest. The suggested maximum of 6.25% allows for a margin of safety to accommodate this uncertainty.
Breeders may not have access to their own databases or software but all breeders of Finnish Lapphunds should be aware of the powerful Koiranet software available via the Finnish Kennel Club website. Unfortunately, there is no similar public access Kennel Club data for purebred registered dogs in Australia. A good substitute is the well populated online database known as The Breed Archive. www.breedarchive.com. The pedigree data entry for this database has been crowdsourced with the support of enthusiasts within the international breed community. This means that there is a chance of missing data and data error. Breeders should check the pedigrees of their own lines for accuracy, to ensure data matches ANKC pedigrees, and/or relevant validated public overseas breed club databases such as Koiranet, and the Swedish and Norwegian Kennel Club Databases.
(Supported by JTO, FKC GBS 3.7.4, FCI-IBS.)