Sunday, July 24, 2011

Inbreeding 101

COI or inbreeding level, is an integral part of planning a healthy litter and usually the first calculation done when selecting mates.

Inbreeding is both good and bad, it is necessary if you want to make a unique breed of anything, dogs, canaries, peas, whatever.  Some breeders refer to it as inbreeding only when they breed together close relatives such as mother-son, father-daughter or brother-sister, others refer to line breeding which is making sure that a particular dog is in the pedigree of the planned litter as many times as is possible, thereby breeding on that "line" to bring in its traits to your pups and lastly there is out-crossing which means that the sire and dam of the litter are not closely related although they are of the same breed. Inbreeding, line breeding, out-crossing are all inbreeding if the COI is above 0.0%. I personally do not use any of these terms as they are misleading. 

In almost every planned litter, there will be some level of inbreeding.  It is very rare that two dogs with at least a few generations of parents on their pedigree won't have at least one common relative in 10 generations, there are just not that many Mudis hanging out on the puszta these days that are not related to another Mudi that existed somewhere on the planet.  Even Mudis with no parents listed on their pedigree have a once pedigreed Mudi closely related to them in almost every case, and if I know about it, I use it in the calculation of their COI level. 

Your dog and every other dog in existence is either not inbred because their COI = 0.0%, or it has a score above 0.0% which means it is inbred to a lesser or greater degree (COI = Coefficient of Inbreeding, a very long and difficult mathematical equation to figure out how closely related dogs on a pedigree are, don't try this at home without proper math genius supervision). 

In order for a breed to become a breed, some inbreeding has to be done.  Low levels of inbreeding provide the typical fixed basic features of a breed, such as color, fur, body, ear and tail type, and all the other things that make us love a breed and be able to identify a dog as belonging to that breed. High levels of inbreeding over a prolonged period can create more uniform breed specimens. To the not so involved breed person, 10 black Mudis may look all the same, but to those of us that have been forced to gallop around the judge's ring a time or too many, we can usually identify one Mudi from another without too much trouble.  We have only a few Mudi kennels that have "fixed" their "look" on a consistent level to the point that identifying any dog in their lineup from another is problematic for even an experienced eye.  This can be done by either using a persistent inbreeding schedule over many generations or by repeating litters many times over many generations.  Inbreeding is not a quick fix and you can just as easily fix traits you don't want.

The level of inbreeding that is acceptable in a breed depends on a few things, among the most relevant are the breeds average COI level and serious genetic health issue challenges. In some breeds the breed wide COI average is so high, it is not possible to get what is GRAS (generally regarded as safe).  In the Mudi however, we still have a low breed average COI so the GRAS level is under 10%, with 6.25% being the baseline to aim for. 12.5% and above is generally regarded as being high, or higher than GRAS, which actually applies to all breeds, not just the Mudi.  Keeping the COI low should give enough breed similarity to the planned pups, while still allowing for a diverse pool of genes to draw from for future litters, which will benefit health, temperament and the purpose of a breed through the years ahead

So what does all this mean to you?  If your dog has a COI of 0.0%, it is not inbred, this usually happens only when you breed two parents that are not from the same breed together.  If your dog has a COI of 0.1%, it is inbred.  Keeping the level under 12.5% is in the best interest of a breed's future health and welfare. But in order to avoid doubling up the risk of a serious health concern in a planned litter, it may be necessary to go a little bit over the GRAS limits occasionally.  It is probably not wise to go over 16% (a 25% increase from 12.5%), no matter what you are wanting to avoid, the chance of doubling up something additionally not desirable also increases the higher the COI level goes up.

Now if you missed that salient tidbit, the chances of reproducing something good or bad are about equal, no matter the COI level.  That is, if you breed with a lower COI, you might have less of a chance to reproduce something bad, but you also have less chance to reproduce what you want (nice head, tail, fur, etc.).  If you breed with a higher COI you might have a better chance to reproduce what you want, but you also have a better chance to produce what you don't want just as easily (tightly curled tail, missing teeth, genetic disease, etc.).  Now how to rectify this trade off into a win-win situation, that is, you keep the COI level low and still get the good features you want in the planned pups?  

If you know the two parents you plan to use in detail and have studied their visible features well (and have passing health tests for both), if you like what you see, chances are you will like what you see in their pups.  If other dogs that are very closely related to the parents you chose also have these same features, that is, their parents, grandparents, siblings, other offspring they may have had previously, also have curly fur, sickle tail, pricked ears, etc., then the chances get better that your pups will too.  It's an educated gamble, but what you see in the parents and those relatives close to the parents are the most likely choice of features that will be available for the pups in your litter too, regardless of inbreeding levels.  Inbreeding to high levels does not guarantee you will get what you want in your litter anymore than low inbreeding does.

Getting what you want in a litter goes far beyond the inbreeding level!  The inbreeding level is a gauge to help determine the possible gene pool diversity available in a breed, it is not very helpful in getting the features you want in your litter.  As the breed average level goes higher, the dogs in the breed start to show symptoms of inbreeding depression, it is akin to a gauge of health in a breed.  Those breeds that have a high COI average usually have common health and reproduction problems which are difficult to avoid.

So to further put this into action, if you have a bitch you want to breed and you have several males in mind that give a COI below 12.5% preferably, pick the males that will also give you the best chance to avoid major health issues, then from those final choices, pick the males that will improve the faults of your female and have family members that also have those same good qualities.  Not a simple task in such a small breed with males spread out over the globe I know!  I said it was possible to breed better litters, I did not say it would be easy!  But then owning a Mudi to begin with is a challenge isn't it, so don't come to the breed expecting it to get easier!

If you want to learn more about COI's, their calculation, what the percentages mean and what can happen when they get too high in a breed, check out the articles tab on this blog. (coming soon)

If you have any questions or concerns, please send me a private email:

Thanks for reading!  

No comments:

Post a Comment