# InBreeding



## Biawhiska (Mar 28, 2008)

What is this exactly? 

Well I know what it is in one way like mating a mother to her son etc but is like a 1/2 granddad 1/2 granddaughter or something like that inbreeding too?


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## Selk67U2 (May 5, 2008)

*Some people call it line breeding Fluffy. Personally i'd never do it. You have to know what your really doing and be confident with it. Not something I need to do anyway.*


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## lizward (Feb 29, 2008)

Yes, there are degrees of inbreeding. Basically it's just breeding closely related cats. And it is a real problem in many breeds.

Liz


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## Biawhiska (Mar 28, 2008)

Oh right, why is it a problem?


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## Cerridwen (Jul 26, 2008)

Some like to say that inbreeding is when you breed closely related cats to each other. In fact, you inbreed even when you breed less related (but still related) cats to each other. It's only a difference in degree. The risk for hereditary diseases and defects to pop up is however bigger the more closely related the cats you breed are.

What you do when you inbreed is to reduce the genetic diversity within the breed. The long term consequences are:

- poor immune system
- low fertility
- an increase in hereditary diseases/defects
- small cats
- shortened life span


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## lizward (Feb 29, 2008)

fluffypurrs said:


> Oh right, why is it a problem?


Well, you head rapidly towards homozygosity - in other words, you lose genetic variation. And if there is a deleterious recessive gene in there then you have problems.

I admit I have done some very serious inbreding in the past - if you have your own stud and a girl is calling then the temptation can be overwhelming - but I am not proud of myself for having done it and this time round I intend to be much more disciplined.

Liz


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## ErbslinTrouble (Sep 1, 2008)

fluffypurrs said:


> Oh right, why is it a problem?


because of the lack of clear lines in areas and some people think they know what they are doing and trying make a line stronger but they end up making it worse and find it difficult to go back to the stronger line.  I think Bulldogs are one of those breeds that they do it in and also the CKCs. Not sure with cats, I've heard of Siamese breeders doing it but it was here say so i can't say it was true or not. It generally causes birth defects and lack of bone density.


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## Abooksigun (Oct 16, 2008)

There was a lot of 'line breeding/in breeding' in the beginning of the Bengal breed. Some breeders do continue to do this but again this has probably led to the certain health issues in the Bengal breed.

Now thank goodness there is a better gene pool so hopefully we can help to make the Bengals much stronger & healthier as well as having the certain health issues tested for.
I for one intend to keep health issues in check & hopefully breed happy healthy kittens


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## Cats Slave (Sep 12, 2008)

When I was looking for burmese kittens I came across so much of it - it almost became a game spotting the re-occurring names on ped certificates.
What level is acceptable though? I saw a lot of girls being mated with grandparents within same catteries and cats sharing one parent.


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## Abooksigun (Oct 16, 2008)

I think from what I can gather anything is acceptable!!

In the Bengal breed I know it has been spoken about that if line breeding hadn't been used then we wouldn't have the rosettes that we have today they think it would have taken longer!!

But the problem is as been said that is probably now why more health issues arise!! A lot of breeders say they do it to lock in certain traits ie bigger rosettes, clearer coat, better profile etc but seems it's at a cost!

Breeders tried to move the breed too quickly & got the pattern that was wanted as flashy coats bring customers but if you don't have health unfortunately you have nothing!! Just my opinion!


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## Cerridwen (Jul 26, 2008)

Cats Slave said:


> What level is acceptable though?


Most geneticist agree on that breedings that generate an IC (inbreeding coefficient) higher than 6,25% on 4 generations is maximum. That's equal to breeding a cat to its cousin.

However, counting on a whole population the IC shouldn't be higher than 2,5% on 5 generations. If you wanna keep safe from an inbreeding depression.


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## kozykatz (May 18, 2008)

As I mentioned before, Burmese breeders are amongst the worst for intensive inbreeding. They are so desperate to produce a string of show winners that nothing else seems to matter! I've been breeding Burmese for well over 18 years now and have NEVER bred a GCCF Champion (have had a couple of Premiers). (There is huge competition at shows in the Burmese section with many very good cats). I don't inbreed excessively and this year I have finally produced a girl who I feel has a very good chance of becoming a Champion. It will feel so much sweeter if she achieves this, being the 8th straight generation of Vervain girls, than if I'd bought kittens from top winning breeders, mated them together and instantly produced stunners. To me that would not be "my" line, it would be someone else's. But after 8 generations I can confidently say I have established MY OWN line and I'm very proud of that.



Cats Slave said:


> When I was looking for burmese kittens I came across so much of it - it almost became a game spotting the re-occurring names on ped certificates.
> What level is acceptable though? I saw a lot of girls being mated with grandparents within same catteries and cats sharing one parent.


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## kozykatz (May 18, 2008)

What would be an acceptable level over 8 and 16 generations?
I don't think that 4 gens tells you anything much but that's just my opinion of course.



Cerridwen said:


> Most geneticist agree on that breedings that generate an IC (inbreeding coefficient) higher than 6,25% on 4 generations is maximum. That's equal to breeding a cat to its cousin.
> 
> However, counting on a whole population the IC shouldn't be higher than 2,5% on 5 generations. If you wanna keep safe from an inbreeding depression.


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## PussyCatNan (Jun 24, 2008)

I never realised realised the world of cats was so complicated!!! How do you know that you have a winner? Looking at the pics on here of the gorgeous kittens I can't see a difference in them (same breed obviously!) they all look like winners...so what do you look for, what makes 1 stand out?


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## Selk67U2 (May 5, 2008)

*There is always a kitten that will stand out from the rest. It's hard to say on here, it's easier to show people. You try to pick the one thats the nearest to the breed standard. In our Norwegians, thats a straight profile(nose to top of head), with slightly rounded forehead, fairly large ears with what they call ear furnishings, which means lots of fur coming out the ears. The face of a Norwegian should look trianglular in shape. There back legs should be longer than the front, long body, undercoat and a waterproof top coat, long tail preferably reaching to at least the cats shoulders and resembling a fox tail. They should have a mane round the neck like a lion. Think thats everything, lol. Trying to do this off the top of my head, lol.*


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## kozykatz (May 18, 2008)

Well, you gradually get to know the type of cats that win at shows, and what individual judges like, so it comes with experience 
Each breed also has a Standard of Points that describes exactly what it should look like, so you have to be familiar with that as well.



PussyCatNan said:


> I never realised realised the world of cats was so complicated!!! How do you know that you have a winner? Looking at the pics on here of the gorgeous kittens I can't see a difference in them (same breed obviously!) they all look like winners...so what do you look for, what makes 1 stand out?


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## Cerridwen (Jul 26, 2008)

kozykatz said:


> What would be an acceptable level over 8 and 16 generations?
> I don't think that 4 gens tells you anything much but that's just my opinion of course.


I don't know of any geneticist that count the IC on 8-16 generations. It's not considered to give you any really valuable information.

My own opinion is that it is of little value to deal with numbers when you get that far behind in the pedigrees. 5-7 generations back it's interesting to see if the pedigree generally is diverse or not and if there are much health problems.

If you wanna go back more generations a rule of thumb is that the IC shouldn't increase more than 0,5% per generation. You can use that so see if there's generally a healthy or unhealthy trend.


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## kozykatz (May 18, 2008)

Interesting, I'd have thought the more generations you include in the calculation, the more accurate the figure. A pedigree can have a very low IC over 4 generations, but very high over 8 or 16, so you get a misleading idea of the situation. You might then breed that cat to another with a very low IC over 4 gens, but in fact they could be very closely related. Ideally you should calculate back to the foundation cats, but that's not always possible of course.



Cerridwen said:


> I don't know of any geneticist that count the IC on 8-16 generations. It's not considered to give you any really valuable information.
> 
> My own opinion is that it is of little value to deal with numbers when you get that far behind in the pedigrees. 5-7 generations back it's interesting to see if the pedigree generally is diverse or not and if there are much health problems.
> 
> If you wanna go back more generations a rule of thumb is that the IC shouldn't increase more than 0,5% per generation. You can use that so see if there's generally a healthy or unhealthy trend.


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## Selk67U2 (May 5, 2008)

> this year I have finally produced a girl who I feel has a very good chance of becoming a Champion. It will feel so much sweeter if she achieves this, being the 8th straight generation of Vervain girls, than if I'd bought kittens from top winning breeders, mated them together and instantly produced stunners. To me that would not be "my" line, it would be someone else's. But after 8 generations I can confidently say I have established MY OWN line and I'm very proud of that.


*I hope she does you proud "Good Luck"*


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## kozykatz (May 18, 2008)

Thanks very much 

she is going to the Yorkshire show on Sat. but I'm not expecting too much as there are so many gorgeous lilac Burmese kittens around at the moment, one of which is her half-sister 



Selk67U2 said:


> *I hope she does you proud "Good Luck"*


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## Selk67U2 (May 5, 2008)

*Oh, lol.....well you never know. I'll keep my fingers crossed for you*


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## Cats Slave (Sep 12, 2008)

kozykatz said:


> Thanks very much
> 
> she is going to the Yorkshire show on Sat. but I'm not expecting too much as there are so many gorgeous lilac Burmese kittens around at the moment, one of which is her half-sister


Yes, good luck on Saturday!!

All this genetic discussion is well above my head! 
I can see where inbreeding is necessary in a developing breed but surely there are enough cats of good type in established breeds that it isn't necessary. But then again if you've spent years breeding cats with specific characteristics I can see the desire to protect and maintain that.
I know I'm taking a very simplistic view of things but as a pet owner I'm more concerned that my kittens are healthy than the fact that their faces are a few mm's narrower than ideal - can you tell my breeder kept on pointing out that Hugo's face is on the narrow side, poor kitty I was sure he came to me with an inferiority complex!


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## Selk67U2 (May 5, 2008)

*Hahaha, ahhh, bless him*


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## kozykatz (May 18, 2008)

Unfortunately when you're a judge, you can't help looking at your own cats and kittens as if you were judging them!! I'm hypercritical of mine 

But who cares if they're not show quality, they still make wonderful pets 



Cats Slave said:


> Yes, good luck on Saturday!!
> 
> All this genetic discussion is well above my head!
> I can see where inbreeding is necessary in a developing breed but surely there are enough cats of good type in established breeds that it isn't necessary. But then again if you've spent years breeding cats with specific characteristics I can see the desire to protect and maintain that.
> I know I'm taking a very simplistic view of things but as a pet owner I'm more concerned that my kittens are healthy than the fact that their faces are a few mm's narrower than ideal - can you tell my breeder kept on pointing out that Hugo's face is on the narrow side, poor kitty I was sure he came to me with an inferiority complex!


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## Selk67U2 (May 5, 2008)

> But who cares if they're not show quality, they still make wonderful pets


*So very true*


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## WhiteNile (Aug 24, 2008)

My Egyptian Mau has the same Great, Great Grandmother in both her sire's and dam's line. But there again, I don't think too many new Maus are brought into the mix too often, which is such a shame, as there are loads of abandoned Maus living on the streets in Egypt just waiting to be rescued. I'm sure with arrangement these cats can be used in breeding (so long as you get them before they're neutered, that is), but I don't know how easy it is to get them registered with the GCCF?? I've often wondered this myself, as if I ever wanted another kitty I might go for an Egyptian Mau rescue, and hopefully bring a new line into the UK.


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## Cerridwen (Jul 26, 2008)

kozykatz said:


> Interesting, I'd have thought the more generations you include in the calculation, the more accurate the figure. A pedigree can have a very low IC over 4 generations, but very high over 8 or 16, so you get a misleading idea of the situation. You might then breed that cat to another with a very low IC over 4 gens, but in fact they could be very closely related. Ideally you should calculate back to the foundation cats, but that's not always possible of course.


Sure, one cat with low IC can be very closely related to another one with a low IC. They could be siblings. That's why you calculate the IC on the offspring. The parents individual IC is less important.

If we wanna be real nasty... the truth is that the inbreeding only increases for each generation (if you were to calculate on the total pedigree, all the way back to the foundation cats) within a closed population. That's why the IC increase for each generation you include in the calculation and if you manage to make a total inbreeding calculation (on all the individuals back to the foundation) you might find yourself having a cat with a total IC of 30-40%.


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## kozykatz (May 18, 2008)

Well, exactly - many UK burmese do have an IC of 30-40% over 16 generations, which is somewhere between half and three quarters of the way back to the breed's foundation cat (Wong Mau)

QUOTE=Cerridwen;333182]Sure, one cat with low IC can be very closely related to another one with a low IC. They could be siblings. That's why you calculate the IC on the offspring. The parents individual IC is less important.

If we wanna be real nasty... the truth is that the inbreeding only increases for each generation (if you were to calculate on the total pedigree, all the way back to the foundation cats) within a closed population. That's why the IC increase for each generation you include in the calculation and if you manage to make a total inbreeding calculation (on all the individuals back to the foundation) you might find yourself having a cat with a total IC of 30-40%.[/QUOTE]


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## lizward (Feb 29, 2008)

kozykatz said:


> I don't inbreed excessively and this year I have finally produced a girl who I feel has a very good chance of becoming a Champion.


Is she from your blue boy?

Liz


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## kozykatz (May 18, 2008)

yes, he does seem to produce rather nice kittens 



lizward said:


> Is she from your blue boy?
> 
> Liz


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