Inbreeding Coefficiant

[student1304]

wow, no need to be rude.
I may not be a breeder of hamsters but I was giving my opinion based on the research I have had to do throughout my degree and I was only giving the 'history lesson' as an example for those that do not know what effects inbreeding can have.
I did not intend to offend or shame anyone, but merely state that inbreeding isn't worth the risk just to achieve a new coat colour.

And while you can have a go at me for stating what I think, my sentiments have been echoed by every other poster on here -

"But by now you might have hamsters that were born without eyes, may be deaf, may develop cancerous tumors early in their lives, etc. What will you do with them? You can't rehome them...you either keep them or have them PTS. Close inbreeding makes for genetically predictable animals but at a cost. Are new colour mutations worth it? Certainly not, if you ask me."

how is it that only I got the rude response?

nevermind, I was trying to help you based on my understanding of the matter.
next time I'll leave it to 'the breeders'.

[crazygal330]

I don't know much about breeding of hamsters but I have I would say a "novice-fair" understanding of breeding in rats. OK not the same. HOWEVER I am aware that many rat breeders inbreed as a way of aiming for healthier lines. If you have a healthy base of genetics, by inbreeding 1 time, you gain a better understanding of the genetics you are playing with, and what you may or may not have. I am aware that there are always risks, and I haven't done extensive research on inbreeding, but of course you are going to run into problems if you are inbreeding when you do not know the majority of the genetics involved.
I believe if you have many generations of history then you already have a fairly good understanding of the genetics you are working with and at which point inbreeding is a useful tool. No one said she was going to closely or repeatedly inbreed. Inbreeding when you know your hammies have a healthy background and you know a lot about genetics and what you do and don't have(recessive and dominant) is much safer than outcrossing with unknown and potentially unhealthy genetics.

In short I believe that randomly breeding any unspecified individuals is far more dangerous than sensible inbreeding.
Not an answer for you I know but I don't think you should be completely slated for just considering the idea

[Erin Loves Dwarf Hamsters]

It would be interesting to hear some of the breeders responses to this, I know that some of the very best ones do inbreed on occasion and do it to actually keep the line healthy and I am pretty sure most of the NHC breeders have done it at least once as many of the pedigrees I have read at shows show that the hams will have as an example the same great grandparents on both sides (mother and fathers side) I have been more curious about it since Mr Bobtail brought Hendrix home, he is from Bourne Valley hamstery and his parents are brother and sister. I guess they were from two different litters but they both have the same parents! I completely trust that an NHC breeder would never do anything to put a hams health in danger but I'd love to hear more about how/why breeders chose to inbreed sometimes

[Cookie Monster]

I have to say I dont really know anything about hamster genetics, but I did some plant genetics in college. I know for the plants we looked at (maybe corn plants?) You got the healthiest crop from back crossing every 4th plant with a parent plan.

Now, I know this doesn't come close to answering your question, but it does make me think if they worked it out for corn plants an answer for hamsters must be out there. I'd be really interested if you found it

[tjherman]

I believe there is some confusion about inbreeding and linebreeding.

From River Road Hamstery's Syrian Hamster Genetics, here are the major breeding techniques:

There are two main breeding techniques - selection and crossing. Selection is the careful choosing of individuals for mating, allowing only the best to become parents of the next generation.

The second breeding technique, crossing, is the pairing of the selected individuals so that the best offspring possible can be produced.

Inbreeding involves crosses of first degree relatives. This is done to concentrate desirable genes. Unfortunately, it will also concentrate undesirable genes so it must be accompanied by rigorous selection. Sometimes, because of limited stock, inbreeding is the only way to develop a line. The inbreeding crosses are the backcross (offspring bred to one of its parents) and the sibling cross (brother bred to sister). Of the two, the sibling cross is considered to be the most risky.

Linebreeding is the pairing of more distantly related animals. Examples are cousin to cousin, aunt to nephew and grandfather to granddaughter. Linebreeding is a slower process than inbreeding when used to perfect traits, but it is considered somewhat safer with respect to creating genetic defects.

Outcrossing is the breeding of totally unrelated animals. It is typically done when you have exceptional animals in every respect but one. A selected individual from the line will be bred to an unrelated animal that has the desired trait. Selected offspring will then be bred back into the line. Even without consideration for show standards, outcrossing is a good way to maintain the production of vigorous animals. (Most mutations for defects are recessive so outcrossing decreases the chance that a defective trait will surface.)

[Pearl Hamletry]

Well I am relieved to see other non-judgmental responses even though no one directly answered my question, lol! Thank you Tamara for the clarification I was referring to line-breeding and not first generation relative breeding that is involved with inbreeding.

[Ren]

Why do you think we're being judgmental? We're giving our opinions about the topic that you posted and doing it nicely. I haven't seen anyone condemning people that linebreed and while it is something that most people are ignorant about, there are going to be a variety of opinions about the topic. I am also curious about how breeders handle linebreeding and why they do it and what sort of results they want/can come up with. But I also think it is better to mix blood as often as you can while still doing occasional linebreeding because it helps the genetic pool stay healthy.

But it is "taboo" for a reason, it's unhealthy if done too much or too closely. Cheetahs, for example: http://lynx.uio.no/jon/lynx/cheetahgenes.html

So naturally people believe it is something to avoid to keep animals healthy.

[tjherman]

I think perhaps some posts were deleted due to inflammatory remarks, hence the response of judgmental.

Like Ren mentioned, there was originally 1 female Syrian and her brood caught in the wild. That female began to cull her young and was euthanized. The offspring were bred together. So all of the very early stock of hamsters were all related. However, you can separate the offspring into 2 groups to create lines and breed within those groups. After enough generations, the populations have less in common genetically. If desired, you can outcross between the 2 lines.

Here's an example of how helpful linebreeding can be: The Dark Gray hamster. The color is like a Golden in grayscale and very pretty. It is, according to breeders, a very difficult gene and few work with it because of that difficulty. Breeders have found that DG hamsters are sometimes smaller as pups and weigh less as adults. There seems to be a higher mortality rate for DG pups. Mind you, this isn't an "across the board" result, but I've talked to 3 DG breeders and seems to happen often.

So to get more DG, you'll first need DG or DG carriers. And then you'll breed them together and hope for more DG. Because DG pups show up less often, it is also hard to test breed for the gene, making it difficult to remove hamsters from the DG line. (It is too unstable to have in other lines, according to the breeders I spoke to.) You can always add more hamsters in (outcrossing) to create more carriers, but ultimately you'll be breeding distantly related hamsters. In the case of DG, linebreeding is one of the few ways to keep the color going.

Cheetahs are a great example of why closely related populations shouldn't breed. But Cheetahs are also a small population already. There isn't a lot of numbers, and therefore less genetic variety exists already.

Breeders are fortunate with hamsters because there are larger base populations and variety to work with to get better results. Ethical breeders will not continue to breed a line of hamsters that have problems. For example, an ethical, reputable breeder wouldn't breed from an anophthalmic white just because it increases the chances of producing Roans. An ethical breeder wouldn't purposefully keep breeding a line that produces hydrocephalic hamsters either. However, some people still do it. Makes places like this forum very helpful to inform and teach people to ask questions about their hamster's background!

[Vectis Hamstery]

In the UK dark grey is considered difficult due to the inbreeding used to establish the colour from my understanding. We are still working on trying to improve the size of the hamsters and reduce the incidence of kinked tails. In dark grey it is important to outcross to a robust non-grey colour (not just an unrelated dark grey) every few generations, e.g. golden. I would accept a certain degree of relation, but would be reluctant to do close matings unless I had a very good reason for my dark greys due the already existing problems. Cream is a robust colour so may stand it better.

I'm not sure what you mean by 'unstable' but as with any colour, you wouldn't want it mixed in willy-nilly with others as carriers of some recessive colours can show changes which don't benefit the other colour. For example my litter will include Goldens carrying Dg - not ideal if my aim was nice goldens but valuable for my lilac/dark grey plans. This is why studying pedigrees is important. There's more to hamster breeding than 'don't breed two satins or patterns together'!

In relation to the original question, I feel that any related matings need to be carefully thought out with a good understanding of the positive and negative points of each animal as the risk of fixing undersirable traits is higher. This is where feedback from other breeders/judges can be valuable as well as comparison with others' hamsters. It does have the similar effect of fixing good traits as well so is a potential tool to be used if you have knowledge of genetics and what makes a good hamster (something which can take a while to get a feel for) and either experience or an experienced mentor. It's certainly not something to start out breeding doing as you could go wrong quickly and it's definitely not an answer to keeping your numbers of hamsters low when breeding. In starting breeding it's best to focus on one species, colour and fur type and choose one which is robust and that you can find good quality animals. That's why cream Syrians are a frequent starting place and dark greys aren't! Some of my black-eyed white matings will have common ancestors due to the limited gene pool, but I hope that with care and attention (and learning lessons from the past such as with dark greys and normal Chinese) problems can be minimised. I wouldn't want a coefficient more than 20% but have no particular reason apart from that's where it turns red on Kintraks! I'd obviously want it as low as possible.

[radiocricket]

I do a good amount of in-breeding and line-breeding, in some of my lines much more than others. My LH line has a higher COI as I know that I'll lose the polygenes for their great coats with an outcross. That being said, this is a line that I've been working with for almost a decade and know that it's a healthy line. As crazygal330 said, it is much more risky to outcross to an unknown hamster. You have no idea what kind of health and temperament that hamster is going to bring and pass on. It always baffles me when breeders bring in pet store hamsters for an outcross.

Regarding the COI, there's no real set number that I adhere to, it's more just knowing my lines. As your COI gets higher, you will start seeing smaller litter sizes (inbreeding suppression). Responsible line-breeding and in-breeding is done to focus a trait and hopefully "lock" that trait into the line (be it color, pattern, coat, temperament, size, etc...). It's a tool that breeders use. It isn't something we do so that we don't keep as many hamsters or because we have no other hamsters to use.

**While the DG discussion is a bit off topic, the problem with DG isn't due to line/in-breeding, but due to the nature of the gene itself. It is likely the same mutation as the grizzled gene in mice. That being the case, you want very robust hamsters in that line to increase the odds and overall size of DG pups.

-Janice