is it ok.....

[snakeman92]

is it ok for mice to inbred

[Scotty Allen]

For all practical purposes yes. It is fine to inbreed or line breed your mouse colony, assuming you are raising them as herp food. The white mouse that we know today has been inbred for dare I say gazillions of generations, that's why they all look exactly the same. If however, you were breeding for a particular character trait, you would have to be a little more selective about your breeding stock.

[Christina]

Snakeman
I dont think inbreeding should be done even for feed purposes.
In the end you will end up with smaller amounts and unhealthy pinkies. Not so unhealthy you wont be able to feed them just that the growth rate may be stunted or it will take longer for the pinkies to grow. As well the mothers may have a harder time getting pregnant or feeding their babies. This all will be due to weak genetics.
Christina

[Jeff_Favelle]

Why would an increase in homozygosity lead to stunted growth? I don't understand the correlation.

[rattekonigin]

An increase in homozygosity not only will increase the frequency of "good" homozygotes, but also the frequency of "bad" homozygotes, so the relative fitness of your entire group of animals will drop significantly...so, you're gonna, invariably, get unhealthy and less productive animals...and, you could get stunted growth as a result of a decreased ability to acquire/process nutrients or some simple recessive genetic factor that would appear much more frequently due to said reduction in homozygosity...just a thought... :)

[Linds]

Originally posted by Christina
I dont think inbreeding should be done even for feed purposes.
In the end you will end up with smaller amounts and unhealthy pinkies

How do you figure? If they are selectively inbred then this wouldn't occur. Swiss Websters and ICR mice are two examples of inbred strains of mice. You really can't get more inbred, these have been selectively bred for quite some time to produce larger than average litters, amongst other traits........

[snakeman92]

so it is ok to inbred for feeder mice

[rattekonigin]

Ya, it's okay...it's better if you can avoid it, but it's not a huge deal...I don't think it will really affect the productivity of your mice in the first generation...

[Christina]

Disagree!
I am a rat breeder and no I do not get scientific about all of the different genetics involved but I do know from experience the downside of inbreeding. I will not inbreed untill at least the 4th generation.
I lost all of my data on the computer not too long ago and just recently had to freeze a mom (who had a stroke) and her babies who unfortunately became malnutritioned.
I was lucky enough to get one of my other moms to wet nurse two of the babies and they are finally striving.
Another one I made a mistake with has babies that are half the size they should be because she bred with her direct uncle.
It took alot of mulling and thought to get everything back to normal in my rat house.
Christina

[rattekonigin]

I'm not saying that it won't have any effect, I just don't think it'll have a big effect if he's just breeding for a couple of snakes...they might have smaller babies and litters, but 15 mice being produced every 3 weeks (I actually don't know the gestation time for mice, but I'm assuming it's the same for rats) is a lot of mice to keep up with if you only have a few snakes, and that's with only 1 female, so it might not hurt to have smaller litters...if he makes sure the mice are fed well and doesn't breed them too young/old/often I don't think they'll produce horribly small and un-nutritional babies...I think the health and size of the mother is a very big factor in the size of the babies she produces.
If he's planning on inbreeding generation after generation, then naturally he's gonna run into some productivity problems not too far down the line....

[Christina]

Linds
The inbreeding you are talking about are scientifically "selected" and that is the key word.
What snakeman is referring to is more like mom and son, sister and brother.
Selected inbreeding is more down the line like great great uncle to niece.
Alot of inbreeding done scientifically is to produce genetic misfits so they can fix the prob!
A good book to read is More Cunning Than Man by Robert Hendrickson it is about a complete history of the rat and its role in human civilization.
Some of it is snoring but it does have its good parts.
( I learned the history of Mickey mouse in one of its chapters lol )
But it does have its serious side to it as well.
Christina

[reverendsterlin]

as long as you regularly select the best stock as replacement breeders and rotate your breeders out as feeders so no one set of parents dominates the population. good records and an ability to tell individuals apart allows older individuals to be culled and replaced with prime aged breeders and reduces brother/sister pairings if you pay attention. Culling is the most common method of husbandry control, anything more closely related than you want gets fed off. I even heard of a guy line breeding for docility, every biter was culled immediately and he claimed to have non-biting mice lol.

[Linds]

Scientifically or not, selective breeding is selective breeding. If done properly, in a lab or at home, it is one in the same. Also, it isn't necessarily more spaced apart in labs than at home. So long as attention is paid to the stock that is being inbred (using only the strongest animals exhibiting the desired traits), it is perfectly ok to breed feeders this way. The longest life of a feeder is a few months, and a breeders lifespan tops out at 9 months. It is good to diversify the bloodline every so often, but inbreeding several generations is not harmful. Mice can be inbred *carelessly* for 9 generations without any defects showing up in the animals. Selectively inbred colonies can go forever since you are constantly refining........