My New Years Resolution- Rex Genetics and Breeding..............

................. calm own dears, it's only for my interest. I have no intention of Breeding !!

I just know that my Rabbit knowledge is lacking as far as Breeding and Genetics go. So I want to learn about my favorite breed

I have not studied genetics since I was at school..........back in 1974 !!


So I hope there will be some folk on here that can help me try to understand it all. I aint the sharpest knife in the drawer :roll:

I don't know much about rabbit genetics but I study some genetics at uni. Interesting stuff

I can tell you about colour genetics if that helps?

as a new rex owner I'd be interested in what you read. i did genetics in Biology at school but that was with fruit flies and other not very interesting creatures.
good luck JJ, that's a really good resolution :wave:

Demismith said:

I can tell you about colour genetics if that helps?

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Any input gratefully received

Jack's-Jane said:

Any input gratefully received

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For people new to genetics, it can be very confusing and hard to understand. Here, I will try to make it a lot easier, by not adding all the complicated information. Before we go on, try remember that B is black and b is brown. I use these genes in the descriptions below.

Phenotype - This is how we describe a rabbit by how we see it, eg. Black or Dutch marked.

Genotype - This is how we describe a rabbit by it's genes. Some genes may or may not be seen (See dominant/recessive). We use a kind of code to describe this, eg. Bb which means black carrying the brown gene, or BB which is a black rabbit that dosen't carry the brown gene.

Dominant - The gene in a capital letter if next to one of a lower case letter eg. in Bb, the capital B is the dominant gene, and the one we see.

Recessive - The gene in a lower case letter if next to one of a capital letter eg. in Bb, the lower case b is the recessive gene, we don't see it but the rabbit carries this gene.

Let me know if you do or don't understand this, you have to fully understand one part before you move on or else it'll get even more confusing.

If you want to go deeper into genes and chromosones and DNA, I suggest you look on the BBC Bitesize website, under Science, Biology and Inheritance

:shock: its all coming back to me now :shock:

Demi do you get bB or bb? So brown carrying black and brown not carrying black?

Georgeypudding said:

Demi do you get bB or bb? So brown carrying black and brown not carrying black?

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If it were bb the phenotype would be brown, so the rabbit would appear brown.
bB would work the same as Bb, so the rabbit would appear black but carry the gene for brown because it is recessive.

Loosy said:

If it were bb the phenotype would be brown, so the rabbit would appear brown.
bB would work the same as Bb, so the rabbit would appear black but carry the gene for brown because it is recessive.

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okay, i think I understand :lol:

Georgeypudding said:

Demi do you get bB or bb? So brown carrying black and brown not carrying black?

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You can't get a recessive carrying a dominant, so no you can't have brown carrying black. You can have black carrying black (BB), black carrying brown (Bb), or brown carrying brown (bb)

When you look at a rabbit, you can see it's dominant genes. You can't tell what recessive genes it has because they do not appear. You can however find out what recessive genes your rabbit carries by doing test matings and looking at the parents information. If you look at a black rabbit, you can see it is black (Or has the B gene). If one of it's parents is brown, your rabbit will carry the chocolate gene, but you can not see this just by looking at the rabbit.

Writing genetics is sometimes a bit confusing. The codes are written in pairs so a black rabbit would have the genes BB unless it carried brown, in which case they would be Bb. A brown rabbit would be bb. Once you learn what letters stand for which colours/patterns it's a lot easier to understand. Remember, the dominant gene(s) always go before the recessive. If you had a black rabbit that carried brown, you would put Bb, not bB because black (B) is dominant over brown (b).

Here is a punnet square and here is what happens when you breed two rabbits...




The top row (BB) can be the male or females genes, although the correct way to write them would be with the buck (male) on the top row, and the doe (female) on the left but if you get them the wrong way around the results will be the same. The first collum (bb) will be the genes of the opposite sex. So, like the punnet square shows, when you breed a black (BB) rabbit to a brown (bb) rabbit, you will get all Black rabbits that carry brown (Bb) because you're putting the B and b together.

Here is another punnet square...




The top row is a rabbit that is black but carries brown (Bb). The first collum is a rabbit that is brown (bb). Some of the babies will be black that carry brown (Bb) and some will be brown (bb).

I would also like to point out, that if a rabbit had the BB (black) gene, it does not mean the rabbit has to be a solid black colour. If the rabbit also had the dilute gene, the rabbit would be blue not black (blue is the dilute of black). There are lots of genes that come together to make a rabbit look the way it does. Don't worry about this too much at the moment, as I was using the B/b gene as an example.


If you understand this I can move on to the actual colours, patterns and markings

Thank you, I'll have a proper look at it this evening xx

Just a tip, I found writing notes down very useful when I was learning genetics

Wow Demi you are very knowledgeable!!

Out of interest how would you (not you personally just people) know if a genetics problem eg bad teeth sore hocks etc is likely to be passed on? And if neither parent shows the problem but the offspring do how does that work?

webbkath said:

Wow Demi you are very knowledgeable!!

Out of interest how would you (not you personally just people) know if a genetics problem eg bad teeth sore hocks etc is likely to be passed on? And if neither parent shows the problem but the offspring do how does that work?

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I'm not entirely sure about things like sore hocks and bad teeth, obviously breeding two rabbits with bad teeth will most likely give you a litter with all the rabbits having bad teeth, one parent with bad teeth and one with good is likely to produce a mixed litter

Demismith said:

I'm not entirely sure about things like sore hocks and bad teeth, obviously breeding two rabbits with bad teeth will most likely give you a litter with all the rabbits having bad teeth, one parent with bad teeth and one with good is likely to produce a mixed litter

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I would have thought traits like that would be on more than one gene which makes it rather complicated!
That's why it's important to know the genetic background of a few generations. If a trait appears somewhere in an animals history there is always the chance that it can carry the genes for that trait even if it skips a few generations.

Loosy said:

I would have thought traits like that would be on more than one gene which makes it rather complicated!
That's why it's important to know the genetic background of a few generations. If a trait appears somewhere in an animals history there is always the chance that it can carry the genes for that trait even if it skips a few generations.

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Yes definately, just like colours. If you breed black rabbits, but a few generations back one of the parents was brown, it's still possible you could end up with a brown rabbit in a litter. The more brown rabbits in the background, the more likely a brown rabbit in a litter will crop up

Is sore hocks an actual genetics problem, or is the problem that through selective breeding to produce the rex breed as we know it, its the fact that they don't have the guard hairs on their feet that then predisposes them to sore hocks?
so they may get sore hocks because of the genetics engineered to produce their coat type? not sure if I'm making that very clear.
But sore hocks isn't confined to rexes.
think i may have confused myself :roll:

JLG said:

Is sore hocks an actual genetics problem, or is the problem that through selective breeding to produce the rex breed as we know it, its the fact that they don't have the guard hairs on their feet that then predisposes them to sore hocks?
so they may get sore hocks because of the genetics engineered to produce their coat type? not sure if I'm making that very clear.
But sore hocks isn't confined to rexes.
think i may have confused myself :roll:

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It's fur density in rex that's the problem. It's usually pet bred rexes that have thinner fur and are more likely to have sore hocks, rex bred for show (exhibition) should have 'intensely dense' fur. If you keep breeding rex with thin fur the offspring will have this thin fur and are prone to sore hocks. I've not spoken to many rex breeders but the ones I have, that breed for show don't have a problem with sore hocks.