Tools for breeders of the Longhaired Dutch Shepherd Dog
On this tiny website you can find world-wide litter data, statistics, and breeding values for genetic diversity. All this is here to promote the idea that maintaining a genetically diverse population is at least as important as taking a stance on the health, character or appearance of the animal!
Things to consider in selection
Individuals contributing too much ↠ rising mean kinship ↠ rising coefficient of inbreeding ↠ degeneration of health
NUMBER OF OFFSPRING
No one individual should reproduce significantly more than others: creating over-contributing families will lead to all individuals becoming more related, which will then lead to unavoidable inbreeding. Offspring numbers should be tracked in second and third generation as well as in the first. In a small breed one individual should generally not contribute more than 5% of dogs of a generation, second generation contribution should stay under 10% and third generation contribution under 20%. For animals with high contributing parents or grandparents, and litters with a high combined contribution between several siblings these limits should be even more carefully monitored. Controlling offspring numbers is the first, the easiest and also the most important line of defence against loss of genetic diversity.
MEAN KINSHIP (MK) - where the breed is going
Mean kinship is a measure of relatedness of the individual to the whole population; the average COI of the individual if paired to all other individuals of the breed at the same time. In this way, mean kinship is a description of the rarity of the pedigree: dogs from over-represented or 'common' pedigrees have high mean kinship, and under-represented or 'rare' pedigrees have low mean kinship. Selecting lower MK individuals for breeding helps in keeping low population COI, and vice versa. MK is a dynamic value, and will change slightly every time any dog produces offspring in the population. The average MK of two individuals is the approximate MK of their offspring together. This makes it very easy to consider pairwise mean kinships in this database, even if both planned parents were not individually entered yet.
DIFFERENCE OF PARENT MK
Pairing individuals with very different mean kinship values should be avoided, even if the COI, or the average MK between the two was desirably low. When pairing an over-represented pedigree with a rare pedigree, it will become impossible to raise the proportion of the rare pedigree in the population without increasing the spread of the over-represented pedigree at the same time. For long-term benefit it is usually better to select breeding pairs from individuals with MK values closer to each other than at the extreme ends of the spectrum, and let change happen more gradually.
COEFFICIENT OF INBREEDING (COI) - where the breed is now
The measure of homozygosity: the proportion of alleles that are identical by descent. Inbreeding calculated from pedigree data is an estimate of genetic diversity of the individual. High population-wide inbreeding halts evolution, and is linked to a multitude of problems related to health and biological fitness. Average COI should preferably be kept under 10% in a healthy population. High COI shows the relatedness of the parents of that individual, but does not correlate with a high relatedness to the whole population: a very inbred dog can still be more valuable than a less inbred dog, if it has a very low mean kinship and the inbreeding can be bred out in the following generations.
Where is all this coming from?
This website was born from a desire to show a very simple way for anyone to be genetic diversity-savvy in a small breed without any fancy tools at their disposal. The framework of this database is just a regular spreadsheet with 3-generation pedigrees constructed from registration data. All analysis on offspring numbers, ratios, breeding ages etc. is calculated in that spreadsheet based on that knowledge. Evolved from just another blog post draft, this small project grew into a complete website that will regularly be updated with current changes and new features.
Additionally, I have provided the values for coefficient of inbreeding (COI) and mean kinship (MK). Coefficient of inbreeding is calculated with ZooEasy™ Online (Reudink Software B.V.), and mean kinship with PMx: Software for demographic and genetic analysis and management of pedigreed populations (Ballou, J.D., Lacy, R.C., Pollak, J.P.). Currently the pedigree data used in these calculations consists of the full longhaired Dutch Shepherd population all the way back to founders (founder pedigrees were based on The History of the Longhaired Dutch Shepherd Dog (Triebels, L.F. 1979) available in English at Longhairworld), as well as of the bloodlines of any related shorthaired Dutch Shepherds, Belgian Shepherds, German Shepherds, x-herders and their bloodlines back to their founders. Because of the completeness of this pedigree data, COI and MK are more detailed (usually higher) than in less in-depth calculations. In some calculations requiring it, 9 years has been set as the average lifespan of the breed, based on personally collected mortality data.
As the author of this website I hope it will give breeders and enthusiasts new angles to look at, and will raise some thoughts and ideas on how selection could be improved. The goal is to educate about genetic diversity and give a more equal footing to all kinds of breeders. Finally, you can always contact me directly and ask about any specific piece of information on this website, and I'll be happy to explain it more. Corrections to any errors are always welcome as well.
Have fun looking at stuff. :)
Sanna Korhonen Dutch Shepherd fan
2020-10-27 HH Dashboard website published
- Finnish Kennel Club | MMT Katariina Mäki https://www.kennelliitto.fi/kasvatus-ja-terveys/koiran-jalostus/tietoa-jalostuksen-tueksi
- Bell, J.S. Popular-Sire Syndrome: Keeping Watch Over Health and Quality Issues in Purebreds (2005). https://www.vin.com/apputil/content/defaultadv1.aspx?pId=11203&id=3853865
- Wellmann, R. and Bennewitz J. Key Genetic Parameters for Population Management (2019). Front. Genet. 10:667. doi: 10.3389/fgene.2019.00667
- Indrebø, A. Animal welfare in modern dog breeding. Acta Vet Scand 50, S6 (2008). https://doi.org/10.1186/1751-0147-50-S1-S6
- Institute of Canine Biology articles about breeding https://www.instituteofcaninebiology.org/blog