Most of the information on this page comes from the Maine Coon database on the Pawpeds website.
Most people know that inbreeding can affect the health of any species, and that genetic diversity is important to keep the species or breed healthy. Pedigree research is an important tool to monitor this. Maine Coon breeders have a wonderful resource at their fingertips: the Maine Coon database, with pedigrees of over 70,000 Maine Coons. Using this database we can calculate the amount of inbreeding in any Maine Coon. Virtually all Maine Coons in the world are in the database.
Inter-breeding related cats, generation after generation, increases the probability that the offspring inherits identical genes, over and over again. This may result in an individual with a smaller variety of different genes in it's makeup. This in turn leads to the immune system becoming less effective. Cats can only produce antibodies with the genes they have, the smaller the number of different genes, the smaller the number of different antibodies produced. The ability of an animal to generate antibodies is drastically reduced if it loses its genetic diversity, in other words, comes from a small gene pool. There may be greater proneness to illness, with longer recovery times.
You will see that each of our breeding cats has, on their page, a chart with numbers on it. What do the numbers mean?
Inbreeding Coefficient
This is a measure of how inbred the cat is. The probablilty of the cat inheriting identical genes is calculated. If the inbreeding was 0% it means that the parents were not related in any way. The higher the percentage, the more related the parents are. Some examples of the percentages of related cats are:
- When a cat is mated with a sister/brother: 25 %
- When a cat is mated with a parent: 25 %
- When a cat is mated with a halfsister/halfbrother: 12.5 %
- When a cat is mated with a grandparent: 12.5 %
- When a cat is mated with a cousin: 6.25 %
Most pedigree Maine Coons have an inbreeding percentage of 12-18%, in other words it is like breeding half brothers and sisters all the time. We aim to keep the Mainelymagic cats below 6-7%.
Top 5 (3 and 2)
The Maine Coon breed is founded on more than hundred foundation cats. However if you look at the pedigrees of the Maine Coons we see in the show halls today, most of them are for a large part founded on the same very few foundation cats. We call the five foundations cats, which are most prevalent in today's Maine Coon pedigrees, top 5 cats. And the three most common foundation cats we call top 3. Finally at the very top we have two cats that have contributed the very most to the genpool of the Maine Coons, and those we call the top 2 cats.
The creators of the Pawpeds Maine Coon Database estimate that the 70% of the genetic make-up of the average Maine Coon traces back to only 5 cats and 40% to only two! At Mainelymagic we attempt to keep our Top 5 percentage to about 50% and our Top 2 percentage to about 20-25%.
Clones
When Heidi Ho Sonkey Bill was bred to Tanstaafl Polly Adeline way back in the late 1970's and early 1980's all their offspring looked identical. They were given the nickname "clones" because of this. Many of today's cats have been linebred (or inbred) using these cats, and so we like to consider the percentage of the Clones in the cat's bloodlines to help determine the amount of inbreeding. The average percentage in today's pedigree Maine Coons is 35%, some are even as high as 50%.
Outcross breeding
The definition of an outcross Maine Coon (which has valuable bloodlines) is a cat that meets at least one of the following criteria:
- 50% or less of the top five cats or
- 35% or less of the top three cats or
- 25% or less of the top two cats or
- 20% or less of the clones
The use of clone and top five percentages is to get an idea about how valuable (from the gene-pool point of view) are the genes a cat is carrying.
From the Pawpeds website Heritage page: "The time has come to strengthen our gene pool through outcrossing, to maximize genetic variability in the cats we produce, to insure hybrid vigor, and to maintain a healthy gene pool for the long term survival of the Maine Coon breed. No one, and no one cat is going to be able to expand the size and diversity of our gene pool in just a couple of generations. It's a long-term project requiring the input and co-operation of a large majority of breeders, not the small minority. It takes a conscious effort and agreement within a breed to value health and actively breed toward that goal. It's how we choose and what we choose to breed that's important. Making that effort will definitely improve the health, vitality and vigor of our cats and kittens. The immune systems of all animals are absolutely dependant on genetic diversity.
Mainelymagic is an accredited Outcross Cattery on the Pawpeds website and is one of only 50 such catteries worldwide that meet the exacting criteria.
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