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inbreeding

post #1 of 15
Thread Starter 
I know lots of breeders who use inbreeding when they are trying to create the best cat for their type. We all know that inbreeding is bad, but people still do it, because they want to continue the breed of their cat, and as we spay so many just for pets, we are constantly loseing the true breeds. I just don’t really understand. My friend has 2 mothers who were Line-breeding, and the first one lost 2 kittens, and her second one she just had premature babies, they are always crying. And we don’t know if they will live.

So I did some searching online to see what might happen to these kittens, and as I read, I relized the reason so many purebred cats have so many genetic problems, and immunesystem problems, which I don’t know if they can be advoided or not.
what kind of breeding do you use?

INBREEDING
(Mating of closely related individuals)

LINE-BREEDING
(Mating of less closely related individuals)

OUTCROSSING
(Mating of unrelated individuals within the same breed

HYBRIDIZATION
(Mating of unrelated individuals of different breeds)
post #2 of 15
Thread Starter 
PROS AND CONS OF INBREEDING
Copyright 1996, 2001, 2003 Sarah Hartwell

For breeders, it is a useful way of fixing traits in a breed - the pedigrees of some exhibition cats show that many of their forebears are closely related. For example, the name of Fan Tee Cee (shown in the 1960s and 1970s) appeared in more and more Siamese pedigrees, sometimes several times in a single pedigree, as breeders were anxious to make their lines more typey.

Many breeders are trying to produce cats which closely meet the breed standard, breeders commonly mate together animals which are related and which share desirable characteristics. Over time, sometimes only one or two generations, those characteristics will become homozygous (genetically uniform) and all offspring of the inbred animal will inherit the genes for those characteristics (breed true). Breeders can predict how the offspring will look. "Line-breeding" is not a term used by geneticists, but comes from livestock husbandry. It indicates milder forms of inbreeding. Line-breeding is still a form of inbreeding i.e. breeding within a family line and includes cousin/cousin, aunt/nephew, niece/uncle and grandparent/grandchild.

The limited gene-pool caused by continued inbreeding means that deleterious genes become widespread and the breed loses vigour and are immuno-depressed or breed true for a particular disorder e.g. epilepsy. Such animals are so inbred as to be genetically identical (clones!), Outcrossing is when the two parents are totally unrelated. In pedigree animals, this often means where a common ancestor does not occur behind either parent within a four or five generation pedigree.

The more that inbreeding is used to get rid of undesirable traits or to fix a desirable trait, the more likely it is that individuals will also inherit the same set of genes for the immune system from both parents, and be born with less vigourous immune systems. The immune system problem is compounded over successive generations as the animals become genetically more uniform, a number of breeds now exhibit hereditary faults due to the over-use of a particularly "typey" stud which was later found to carry a gene detrimental to health. By the time the problems came to light they had already become widespread as the stud had been extensively used to "improve" the breed.

The ultimate result of continued inbreeding is terminal lack of vigour and probable extinction as the gene pool contracts, fertility decreases, abnormalities increase and mortality rates rise. On the other hand, too much outcrossing will cause loss of type and therefore the loss of a distinct breed.

When trying to bring a breed back from the point of extinction, the introduction of "new blood" through crossing with an unrelated breed is usually a last resort because it can change the very character of the breed being preserved (as noted by cat fanciers when Russian Blues were crossed to Blue Point Siamese after World War II). In the cat fancy, breed purity is equally desirable, but can be taken to ridiculous lengths. Some fancies will not recognise "hybrid" breeds such as the Tonkinese because it produces variants Such fancies have lost sight of the fact that they are registering "pedigree" cats, not "pure-bred" cats, especially since they may recognise breeds which require occasional outcrossing to maintain type!

One formula to reduce inbreeding and slow down the loss of vigour is to line-breed for 2-3 generation and then out-cross to an unrelated line (or occasionally another breed) to get back hybrid vigour and genetic diversity. However with the emphasis on breeding for type and competitiveness on the showbench (and when making a sale), the typey studs get used more and more often and there is less and less chance of finding a truly unrelated line.

How can you tell if a breed or line is becoming too closely inbred? One sign is that of reduced fertility in either males or females. Male Cheetahs are known to have a low fertility rate. Failure to conceive, small litter sizes and high kitten mortality on a regular basis indicates that the cats may be becoming too closely related. The loss of a large proportion of cats to one disease (e.g. enteritis) indicates that the cats are losing/have lost immune system diversity. If 50% of individuals in a breeding program die of a simple infection, there is cause for concern. Ignoring the fault and continuing to breed from the cat will cause the faulty genes to become even more widespread in the breed, causing problems later on if its descendants are bred together.

The ultimate result of continued inbreeding is terminal lack of vigour and probable extinction as the gene pool contracts, fertility decreases, abnormalities increase and mortality rates rise. On the other hand, too much outcrossing will cause loss of type and therefore the loss of a distinct breed.
post #3 of 15
When I was breeding my rexes I did line-breeding and outcrossing. But I studied the pedigrees of the male I was using to see how inbred/line-bred he was.

I always had healthy kittens because of it. My one black smoke (who's father was a chocolate) was spayed. One day I sat down and really took a look at the father's pedigree. He was, IMO, a little too inbreed to get the chocolate color but my cat's mom was an outcross. Taz will be 18 yrs old in July and she's never had any problems health-wise.

Some breeders become "cattery blind" and that's where you have problems with litters, health, etc. You have to study the pedigree and line breed and outcross every few generations if you want healthy cats. You can't just put to "pretty" cats together if you don't study the pedigrees.
post #4 of 15
Quote:
Originally Posted by GoldenKitty45 View Post
When I was breeding my rexes I did line-breeding and outcrossing. But I studied the pedigrees of the male I was using to see how inbred/line-bred he was.

I always had healthy kittens because of it. My one black smoke (who's father was a chocolate) was spayed. One day I sat down and really took a look at the father's pedigree. He was, IMO, a little too inbreed to get the chocolate color but my cat's mom was an outcross. Taz will be 18 yrs old in July and she's never had any problems health-wise.

Some breeders become "cattery blind" and that's where you have problems with litters, health, etc. You have to study the pedigree and line breed and outcross every few generations if you want healthy cats. You can't just put to "pretty" cats together if you don't study the pedigrees.

I think you said that very well, GK. A cat's type, is just as important as the pedigree. If one linebreeds, or for those comfortable for inbreeding, it isn't just saying "the Mom and Dad are healthy", it is looking at each cat in the past generations on both sides, and look at the health.
post #5 of 15
Quote:
Originally Posted by Miyu View Post

How can you tell if a breed or line is becoming too closely inbred?
As a breeder, instead of looking at "signs", I can look at the pedigree and check the inbreeding co-efficiancy, and as a breeder that should be their choice to decide. I personally like seeing as little inbreeding or linebreeding. If a breeder is experienced, and knows their lines, I don't see an issue with linebreeding.

I do want to say that the breed of dog, I have Old English Sheepdogs, seem to be being inbred more and more. We just lost our Jack at 4, and I personally feel at studing some of the pedigrees and being knowledgable about this breed. (I do not breed them), but I feel if more outcrossing isn't done soon, this breed is going to be lost to those who would rather see type and lose the health. While I love this breed, I could never place myself in the position to lose a friend in the circumstances we did again. I may be wrong in my opinion, but I do believe the problem in the OES dogs is inbreeding and close linebreeding. My experience of losing my pet, can make me a little narrow minded through grief, though.
post #6 of 15
Thread Starter 
LINE-BREEDING

Pro-Avoid inbreeding of very closely-related cats, but cats are still "pure".
Produces uniform or predictable offspring.
Slows genetic impoverishment.

Con-Require excellent individuals.
Does not halt genetic impoverishment, only slows it down.

OUTCROSSING
Pro-Brings in new qualities or reintroduces lost qualities.
Increases vigor.
Cats are still "pure".

Con-Less consistency and predictability of offspring.
May have to breed out unwanted genes accidentally introduced at same time.
May be hard to find individuals which are true outcrosses.

I think every breeder thinks that they are great, I guess that is what you mean by “cattery blind” right? That is why I could never do it like that. I could not turn a blind eye, I only ever breed by hibridization its the only way i know works, all my kitties have been 100% healthy, and that is what matters to me first, not type,

HYBRIDIZATION
Pro- Brings in new qualities or reintroduces lost qualities.
Increases vigor, may improve immune system and reproductive capacity.
Introduces totally new traits e.g. color. Fur type.
May result in new breeds.
The offspring are considered "impure" for many generations.

Con - Unpredictable - new traits may not all be desirable.
Must choose outcross breed whose qualities complement or match own breed.
May take years to eliminate unwanted traits/loss of type.
May take years to get consistent offspring.

I have Produced many variants not suitable for use in breeding program.
to some That’s the bad thing, when I choose to breed I can only hope for the desirable trades to be passed on, and sometimes even with 2 purebreds very similar and both have what I want in kitten, sometimes they just turn out to be muts. Which feels like a loss for me. And they are never anything more than pets.

But it is soo sad what happened to these kittens, my roommate has, she has been breeding for 10 years, so she thinks she knows it all, and well I can’t really object, I have no proof she doesn’t, after all I don’t know it all. So I was hoping I can get some advice from you.. We tried feeding them, but they wouldn’t take, she pointed out that their organs may not have fully developed. and they can’t get to moms breast; and mom isn’t producing much milk at all since they are so premature, mom wasn’t fully ready to start nursing. right now mom and kittens are at the hospital getting hydrated. but we don't know what will happen. We don’t know how things are going to turn out. I guess this is something you have to expect could happen with line-breading. You can have losses of kittens... I have personally never been through it. But it is difficult.
post #7 of 15
Thread Starter 
Quote:
As a breeder, instead of looking at "signs", I can look at the pedigree and check the inbreeding co-efficiancy, and as a breeder that should be their choice to decide. I personally like seeing as little inbreeding or linebreeding. If a breeder is experienced, and knows their lines, I don't see an issue with linebreeding.

I do want to say that the breed of dog, I have Old English Sheepdogs, seem to be being inbred more and more. We just lost our Jack at 4, and I personally feel at studing some of the pedigrees and being knowledgable about this breed. (I do not breed them), but I feel if more outcrossing isn't done soon, this breed is going to be lost to those who would rather see type and lose the health. While I love this breed, I could never place myself in the position to lose a friend in the circumstances we did again. I may be wrong in my opinion, but I do believe the problem in the OES dogs is inbreeding and close linebreeding. My experience of losing my pet, can make me a little narrow minded through grief, though.
That’s exactly it, she studied the history and things seemed ok, the thing is the cat is really rare, and there isn’t much left of it, but hybridization is not an option for her. It’s not an option for her breed because it can still be outcrosses. She wants type, and health and outcrossing is done regularly, but she has also lost a lot of type. They are just purebreds and nothing special. I remember her saying mom and dad are typie. I just don’t get it, why do we take them to shows so a judge can say, this cat has the perfect body for its breed. To me the ones with the big heads are the most cute. But they don’t get the award. Gosh, it just seems too crazy
post #8 of 15
IMO cattery blind is only using the cats you have and refusing to bring in "new blood" from time to time.

Not sure what was going on with your friend's cats, but sounds like her cats have something genetically wrong with them or they have some kind of virus they are carrying that kills/deforms the babies.

When something like this happens, its best to spay/neuter the involved cats (pet them out if you want) and start over with healthy lines. While every breeder has an occasional "bad experience", this seems more then just a one time thing.

Its hard when you have a rare breed to find genetic diversity. In the case of the Cornish Rex cats, the first ones sent here from England had massive problems (because of inbreeding) and the breed was almost lost! We had to literally start all over with outcrossing to other breeds (siamese) and rebuild up a healthy gene pool. The rex gene is recessive - rexes crossed with another non-rex are all straight coated, not curly. So its a long process.

BTW just what kind of cats is your friend working with? What breed?
post #9 of 15
Thread Starter 
Hello again; thought I would update on the kittens. The vet tube fed them, and said they are not likely to stay alive since they are so underdeveloped, 2 died at the vet we took them home and one died, so he was right, I buried him in my garden, one is still with us and she is sucking, mom is soooo small, she said she was a runt, and I think she is still a baby herself it takes 2 years for these cats to finish growing, and is is only one year. her mother has 5 kittens and they are all healthy. We gave the premature baby to its grandma to nurse, and she welcomed the baby, but the baby did not want her milk, because it wasn’t mom. But cats are soooo smart, I think grandma already knew that mom is unfit, because before, she would go in when mom is not there and take the babies in to her nest, mom flips out at this. But mom kept leaving the babies even though they are premature which would cause them to become hypothermic. But we have one, she is 4 days old. White female. Or how would you count a premature, - 2.5 weeks? The vet didn’t mention anything being wrong with the kittens other than being premature. They are like 3 weeks early. When we got them back, they had a bit more fur. Should we take them back and look for a virus?

And mom is getting spayed and a new home after this, that was already decided before she had the kittens. If all kittens die, then she will go right away, if not then we will wait till she is ready to go. And adopt her too. she has a very small cattery, only 5 cats and I have only 2. She has the Turkish Angora, odd eye white and black, I have 2; Turkish van, calico. 1/2 breed, and I got a 1/2 breed turkish angora from her. they are so cute, I should show pictures. I have always wanted to breed turkish Angoras and vans, and I feel lucky to know breeders, if I ever wanted too I could...Because they are so rare, and I would want to better the breed. Could you imagine an odd eye calico van? in Turkey the odd eye Kedi is most loved. They are so rare, I wish there were more people trying to bring them back. but the cost for a purebred breeding Queen, or stud is ALOT, because they are so rare... seems like prices are always going up too with everything.

I also have a lot of breeder friends, some are ok, some are bad (not really friends, jsut people I know) But I have a hard time trying to understand why they do the things they do sometimes. So for now I think I will just stick to helping cats who have no home rather then breed.
post #10 of 15
Thread Starter 
can I ask what kind of cat you breed? and when did you fall in love with it, before you started breeding?
post #11 of 15
In the US, Turkish Angoras and Van are not rare. The breeders here have very healthy cats (good friend of mine breeds the Angoras and she's never had a problem with premature babies with her cats).

I was breeding Cornish Rex cats. My ex-husband was the one that got us into the breed as he had allergies. I thought they were one of the ugliest cats, but you fall in love with the personality and they really are cool cats.

We now own a mixed breed and an Ocicat, Charlie, who we are showing in CFA and ACFA to his Grand Championship (then he will retire and be spoiled - as if he isn't spoiled now )

I don't breed any cats anymore. We want to travel when I retire from work.
post #12 of 15
Thread Starter 
Yeah there are a few Turkish Angora, but the national beauty is the odd eye white, and that is rare. Nearly all are related to each other. But that will take years to fix. I loved this cat for 14 or more years, but it was very hard to find, I looked it up in every cat book I could get my hands on. and couldn’t find it for years and years, I keep looking up Turkish and the only thing listed was the van. my friend love it too, I had no idea, but we saw it on TV together, and I had no idea until she started breeding. So she found it before me by going to a cat show and asking a Judge, because the Van Kedi is the original name of the Turkish angora, so looking under Turkish, we had no luck finding the breed. only the turkish van, which is a different breed, with nearly the same name.. But when my friend explained to judges, “Van kedi and white odd eye,” they informed her the proper name for that breed. I never found it until the internet was introduced to me, and my friend started breeding. And it is more known now then it was, because of breeders, because other people and their passion to breed and promote it at shows, people know more about it. We got all our cats from the States. There are no Turkish van breeders in this city for 1million people, and there is only one angora breeder. And there are lots of rex’s cats,(don’t know what kinds) ragdolls, Persians, bangles, Siamese, manx, and Maine coon. I love them too. I guess the fact that in so many cat books about different breeds and I couldn’t find it, and it took me years to find, and how we can only get them from the US and not here, and they are all so closely related, to me that is rare. And if you study the history, it is also known as being a rare old breed. I just hope people don’t inbreed it to keep type and end up whipping it out. But I guess we will see... Just thought I would share ^_^

So our last premature baby is looking so good, her name is Hero. Mom is producing lots of milk, and she is growing more fur.
post #13 of 15
My friend imported some of the original Turkish Angoras from the Ankra Zoo - the Zoo was the one that controlled the breeding of the cats - that's why they were so hard to find outside the zoo. And they also bred only the whites (in 3 eye colors).

The color TA's were culled or killed; but he color genes were still in the cats. In the US the TA's are recoginzed in colors as well as the whites - whites still being most popular.

If you and your friend are interested in TA's, why not save up money and import some from the US back to your area. We have healthy lines that are not so inbred.
post #14 of 15
Thread Starter 
she did get one form turkey, and they had funny temperments. but you don't get a fmaily history when you import a cat you have to start it, and if you did get a history, you don't know if its a true history. and she did get the rest from US, I'm not sure from who. but she has been breeding them for 10 years and she is stopping after these kittens, all females and males are getting fixed and becomming pets. and some are in the process. and she had all colors at one time, at the moment she only has 3 colors.
post #15 of 15
I outcross and we (Swedish Devon Rex breeders, actuarally Devon Rex breeders all over the world) ) "hybridize" to. I have plans on using Aby in my breeding program.

Since all Devon Rexes have a common ancestor, Kirlee, it's hard do avoid some kind of inbreeding (I don't care what people say, line breeding is just a nicer word for inbreeding). However, there's no problem staying under 2% inbreeding coefficient (on 4 generations). The most "inbred" mating I've done was 1,56%.

I also keep a good look on the total inbreeding coefficient, meaning calculating the inbreeding coefficient with ALL the ancestors behind the cats. A make sure it doesn't get higher, but gets lower.

My breed have had it's fare share of inbreeding problems and most of us who breed Devon Rex wanna stay away from such problems in the future.

Inbreeding isn't healthy. It really isn't harder than that. It's easier to gain fast results, but not the healthiest way.
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