# Breeding and inbreeding - how far??



## elsamarie (Mar 16, 2009)

Can anyone help me on what is a 'safe' level (if there is a safe level) of inbreeding? For example would I be able to breed a doe with with a buck from her brothers litter if her brother was bred with a totally unrelated doe? 
And would it make any difference if the doe i wanted to breed had both the same parents as her brother or just the same father??

If i did breed that litter then any further breeding would be the offspring with new unrelated stock.

From what I have read so far my understanding is it would be relatively safe as problems occur with continous inbreeding of mother/son, father/daughter, brother/sister. I just want to be sure though and get some others points of view.

I've probably made that sound really confusing but I just want to be sure I am breeding responsibly.

Elsa.


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## Angelmouse (Oct 3, 2008)

I am unsure myself and for that reason I have never bred mice related to one another, this makes it hard as its not easy getting hold of healthy longhaired mice :roll: but I would be interested to here what other people do or recommend


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## SarahY (Nov 6, 2008)

Inbreeding is very useful as it quickly reveals hidden strengths and weaknesses in your stock, and with inbreeding faults only arise if they are there to start with. I inbreed quite heavily because I like to know if there's something wrong, and equally if I've something really good going with the line I can cement it in. Some lab strains of mice have been bred brother to sister for hundreds of generations and they are perfectly healthy.

In your case if you inbred one generation and then immediately outcrossed, the new generation should be healthy but it'd be hybrid vigour they are displaying and if your stock has existing faults they would remain uncovered.

Sarah xxx


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## Effy (Dec 30, 2008)

'Inbreeding' is fine. Even in the human population, where we're all pretty much the lowest of the low, genetically, because we don't select 'breeding partners' and think of more advanced features as 'ugly, the chances of 'mutations' and 'health risks' are only VERY slightly increased. With animals which are selectively bred and have any health problems noted and stopped, these chances are EVEN lower. Sometimes, 'outbreeding' increases the chances of health problems more than 'inbreeding', since you can never know 100% what the other breeder has told you is complete and true about their stock, whether as you would know more about your own lines and would be able to avoid more of the potential problems.

In nature, animals don't choose non-related mates...they don't care, as the whole idea of 'incest' is a totally human thing. It is a ridiculous social idea we have stuck to. Animals simply choose based on strengths and weaknesses, naturally selecting mates who are healthier and would cause less problems in the health of offspring...it doesn't matter whether the strongest they could find is their mother, brother, cousin or so distantly related it's not worth naming!

So if you're careful to watch ALL offspring and THEIR offspring for any health problems and make sure they aren't passed on if possible, you shouldn't have any problems linebreeding. Especially only a handful of times, which will most likely be necessary-when you find something new that you'd LOVE to keep putting into all your mice, because if you don't breed within that immediate family unit, that new occurance will most likely be lost.


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## elsamarie (Mar 16, 2009)

Thanks for that, from what you've said so far it looks like I may be best breeding initially at least from related stock as you said to identify any problems. I guess it's true what you say about 'incest' being a human concept - never thought of it that way!

Elsa


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## daisy (Oct 4, 2008)

i wouldnt say inbreeding is a ridiculously social idea in humans...... inbreeding in humans is proven to be dangerous for growth and functionality problems.... much more so than in other species ie- rodents!


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## Effy (Dec 30, 2008)

Considering we're not 'bred' for quality and don't really seem to CARE what genes we pass on to our kids, the increase in risks of problems is still MINUTE.
I'm not saying everyone should do it...I'm just saying that outlawing it, purely for that reason, is daft, as it's not a good enough reason and is only used because people think saying "I think it's icky" would be an even worse reason.
You can tell that's not the real reason it's illegal, since even couples who are sterilised and have their reproductive organs removed can be locked up for it.

It's only because we don't chose our partners for breeding reasons and we take longer to have children, that the risk is greater than in rodents. =]


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## daisy (Oct 4, 2008)

there are phychological studies that would disagree about not choosing our partners for breeding purposes. its written into our genetics to follow the natural rules for survival of the fittest.... an example of this is men prefering curvy women as larger hips make for more sucessful child bearing... interesting stuff...

personally i dont know anyone that is interested _in the slightest_ with procreating with their relatives! :shock:


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## Effy (Dec 30, 2008)

Of course you don't, it's a social thing put into us from before we understand...and who would tell you? x3

As for that science stuff about curvy women...that really doesn't happen anymore in society. We're too easily influenced by the things we hear and see, which is why we're struggling with obesity, anorexia, bulemia and people who are attracted to bodies which are totally UNnatural. Humans are actually getting to the point where we are halting evolution, since we're choosing aspects in our partners which make our offspring weaker...or just make us unable to reproduce at all. So many men are attracted to women so skinny they can't even have periods. Too many people regard change as disgusting.
Like webbed feet. :lol:
I know it's a stupid example...but what if it's how we're supposed to go? rofl

We're chosing weak aspects and it's getting rid of all the strong, healthy genes.

It's also fact, proven by studies, that if you're separated from a sibling, then meet with that sibling and another person who has the same attributes, you're FAR more likely to be attracted to the sibling than the unrelated male. This is so common, that it's given way to the naming of an 'illness', which allows many people to escape incarceration for incestual activities-GSA, Genetic Sexual Attraction.
Most public studies state that 50% of siblings who meet like this are attracted to each other...but the figure is a lot LOT higher than that.


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## Peteyandthegang (Jan 20, 2009)

Effy said:


> It's also fact, proven by studies, that if you're separated from a sibling, then meet with that sibling and another person who has the same attributes, you're FAR more likely to be attracted to the sibling than the unrelated male. This is so common, that it's given way to the naming of an 'illness', which allows many people to escape incarceration for incestual activities-GSA, Genetic Sexual Attraction.
> Most public studies state that 50% of siblings who meet like this are attracted to each other...but the figure is a lot LOT higher than that.


Perhaps this is more because these people recognise a piece of themselves in the sibling...like they sense some kind of relationship, and mistake it for sexual attraction (because what else would it be?) rather than brother sister matings ever actually being ideal breeding conditions. Also, what makes you say the figure is higher than the studies have said?

Most peoples feelings about incest are definitely there for a good biological reason. You are right about society becoming messed up and people gettting confused about whats attractive and healthy, and that is caused by society. But brother-sister, father-daughter type incest is clearly, more times than not, going to end in health problems further down the line and its far more desirable to introduce the right kind of new genes into the mix


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## elsamarie (Mar 16, 2009)

I suppose incest can be looked at from two angles - the concept of incest being unacceptable and 'dirty' is something created by society but the legal reasons behind incest being unacceptable are there for medical and biological reasons. Once a law is made it must apply to everyone, regardless of whether or not they have been sterilised; relax the rules for different reasons and it then causes more problems and ill feeling between different society members.

It does pose the question though, taking that inbreeding produces more health risks in humans than it does in mice, of how a mouse's genetics, DNA, chromosomes etc differ from a human's - especially as mice are used for the testing of drugs etc that are designed for human use?


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## Effy (Dec 30, 2008)

That's the thing though, it's not fact that it causes more health problems in humans...just that it does at the moment, comparatively, since we aren't selectively bed. It's only bad pairings we've made which increase the risks...the same as in mice. If you've seen all the cancerous mice from Wales, due to one group of mice breeding and breeding over and over. That group of mice is the mouse equivelant of our society. If we organised ourselves into the human equivelant of show standard mice, the 'risks' would be exactly the same. =]

As for what else the attrction could be, Peteyandthegang, it is exactly what you've said, we recognise genetics. We don't realise it, but we do. We see things in others that are similar to our own genepool, because this makes our traits stronger. This is why women so commonly choose men like their fathers. =]
I never said brother-sister was IDEAL...I just said that it's not as horrendous as people make out and that the risks, given that we're all awfully 'bred', are still minute.

The figures are always higher than the released versions. 
You have to stay up to date on these things, tracking them and taking part in research to always know the facts. People rewrite and take things out of context and rearrange things over and over before things are published. =]
(Take the pope's comments on condoms for an up to date example :roll: )


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