new Zealand rabbit genetic question

[Timmy]

Ok so it's my understanding that white new Zealands are actually Albino reds. so my question is would crossing a red and white result in both red and white offspring?

 

[Bunnylady]

Bobbi Schott's Color Genetics of the Netherland Dwarf Rabbit is pretty good. (I had a copy 15 or so years ago, but I lent it to someone and it never came back, so I'm having to rely on memory here.) I know that Dwarfs can seem kind of frivolous to a meat rabbit breeder, but Dwarfs do just about everything color-wise that other breeds do. As I recall, the only problem I had with the book is that it didn't have any pictures. Since so many people are visual learners, actually seeing something rather than having it described to them makes it easier to understand and remember. I have flipped through a couple of books that did have pictures, but unfortunately, I don't remember their titles. There are any number of websites that go into rabbit coat color genetics; some are quite good, others seem to just be parroting what others have said without really understanding what they are saying.

The difficult thing about breeding the colors of the New Zealand together, is that the colors themselves don't have much in common. There are a number of genes that influence coat color, and each of the NZ colors relies on different ones to achieve that color.

Look at it this way: if you think of the Chestnut (wild-type coloration) as your basic rabbit color, then you go, "what do I have to do to a Chestnut, to turn it into a (insert your chosen color here)?"

Some colors are easy. REW is probably the easiest. To turn a Chestnut (or any other color) into a REW, all you need is two copies of the REW gene (c). All the other genes are still coding for all the other things they code for, you just can't see them, because that pair of REW genes shut down all pigment production.

Turning a Chestnut into a black is almost as easy; there are two ways to do it. One is a self gene. There is a gene, called the Agouti gene, that causes the agouti pattern of the Chestnut. The Agouti pattern has white on the insides of the ears, white around the eyes, around the nostrils, under the jaw, between the toes, under the belly, and on the underside of the tail. The body hairs of the Agouti are banded, as described before, with a black tip, a lighter band in the middle of the hair, and a blue-gray base. There is another gene in the same series that is called the self gene. A self patterned rabbit is solid black from nose to tail. Agouti is dominant, self is recessive, so if a rabbit has an agouti gene, it will be a visual agouti. The only way you will see self is if the rabbit inherits a copy of it from both parents.

Another way to get a solid black is with the steel gene. Steel happens in the E series. A rabbit with two copies of the steel gene will be identical to one with two copies of the self gene, even if it actually has agouti genes.

Red is a different kettle of fish entirely. Though it might look like it is one color from nose to tail, red is actually an agouti color. It takes a lot of fiddling to turn a chestnut into a red!

The first thing you need is non-extension genes (e) in the E series. The non-extension gene is the most recessive of the E's, so the only way you will see it is if the rabbit gets a copy from both parents. With non-extension genes, the black on the body hairs of an agouti-patterned animal gets pushed right to the very tip, creating a much wider light band in the middle. This animal is pretty much orange in color, with just a bit of "smut" on the ends of the body hairs.

To get that deep, brick red color, you need rufus modifiers. There are several of these, and basically, they just code for more or less of the red/yellow pigment. A rabbit that most of its rufus modifiers in the + form will be redder, one with them in the - form will be more yellow.

Our rabbit still has a white belly, though, and to get the red coloration there, you need the wide band genes. Wide band is recessive, so once again, both parents have to carry it for a baby to show it. Wide band acts a lot like the non-extension gene, in that it creates a wider light band on an agouti patterned animal's body hairs. Combined with the non-extension, there is virtually no black on the body hairs. Wide band also allows the red pigment to appear in other places where the agouti gene normally doesn't let it show, like the belly and the underside of the tail.

This is why people get so frustrated trying to breed the colors of the NZ's together. With a random NZW, all you know is that it has the REW genes; you can't know what it has at the A, the E, the W, etc. sites. The odds that a random NZW has non-extension, wide band, and all the right rufus modifiers are not great, so it's a crap shoot whether you could get decent reds when breeding to one. You might have better results breeding for blacks, but that isn't a guarantee, either.

 

[Syl in Tucson]

Bred same buck to another REW NZ and she had her babies last night. All the babies are white this time. (Well, they're pink) Didn't count on that! Also another HUGE litter. Not sure what it is about the number 13, but it keeps coming up. I hope this momma is better able to feed her brood than the other momma.

 

[Bunnylady]

We have a Cali buck that we have bred to our two NZ does.....one broken blk/wht and one red. The Cali genes must be strong because, out of the 8 kits that our broken doe had, 2 were broken blk/wht like her and the other 6 all turned out to look like Calis. Our red NZ doe just had her kits last week......looks like she has all black or cali-looking babes. We haven't bothered them, so I don't know how many of each she has yet.

Sorry about that, but I feel better, having gotten that out of my system.

It's just that I have heard people say that sooooooo many times, and that just isn't the way it works at all.

If this buck is a purebred Cali, he has two copies of the Cali/Himi/pointed gene at the C locus. All of his babies will get a copy of the pointed gene from him, because that's the only thing he has to give in that place. In the C series, there are 3 or 4 genes that are dominant to the pointed gene, and one (REW) that is recessive to it. Since your does aren't pointed in color, what they have determines what the babies look like.

You say that your does are New Zealands; one broken, one red. For simplicity's sake, I will assume that they are purebreds, and are just carrying genes that are typically found in New Zealands.

Since these does aren't NZW's, they clearly have at least one copy of the full-color gene. Full color is dominant to both pointed and REW, and just looking at them, you can't know if they have one copy of full color and one of REW, or two copies of full color.

Any baby that gets the full color gene from its mother will be full colored - that means that they have the ability to produce both black and yellow pigments, in whatever places on their bodies that the rest of their genetics allow them to.

If a doe produces a white baby (either REW or pointed) that means that the doe has a REW gene. A doe with one full-color gene and one REW gene has an equal chance of giving either gene to any particular baby. Put another way, every baby has a 50% chance of getting the full color gene,and a 50% chance of getting the REW gene.

For each baby, it's like flipping a coin. With your buck, you know what he's going to give - the pointed gene, since that's the only thing he has. If the doe gives the baby the full-color gene, you get a full-color baby. If the doe gives the baby a REW gene, well, REW is recessive to pointed, so you get a Cali colored baby. In any given litter, you could get all Calis, no Calis, any combination of Cali and full colored babies, and it's still just like flipping a coin that many times. Genes don't overpower each other to get inherited, it's only in getting expressed that dominance comes into the picture.

 

[balloonflower]

There are people here who know way more about rabbit genetics than I, but I believe the color variations are just that--colors. The reason rew are most common meat rabbits is that the pelt is also most desirable on a larger scale--white can be colored to whatever. I have silver fox and love their coats, but there is limited use for the black fur, even though it is gorgeous.

NZ aren't the only good meat rabbits--Californian, Satin, Chinchilla, Palomino, Silver Fox....you're just looking for a good end size, growth rate, body type, and meat-to-bone ratio.

 

[aprille218]

Depending on what the albino rabbit carries for other genes you may end up with many different colors but no REW's (albinos) unless the colored rabbit carries the small c albino gene.
Aprille

 

[Bunnylady]

Some rabbit people will start foaming at the mouth if you use the word "albino," you want to be careful using that word. Even though that's what they are genetically, the word we use is White" or Ruby-eyed White (REW).

Obviously, every REW rabbit is carrying the genes for other colors, you just can't see the results of them because the REW genes shut down the production of all pigment to the coat and eyes. A NZW may be carrying red genes, or maybe not - you can't tell. A lot of the NZW's that I know of have produced Steel when crossed to other colors, and since Steel and Red happen at the same place in the gene code, they can't be both a Steel and a Red at the same time. Actually, one copy of Steel (Es) and one of Red (e) gives you a black rabbit that looks exactly like a black self.

Both red and white are recessive colors; the only way you see them is if the rabbit gets a gene for them from both parents. Red is in the E series; a red rabbit has two copies of what is called the non-extension gene (ee). White (REW) happens in the C series, so your NZW has two copies of the REW gene (cc). If your hypothetical New Zealand White carries at least one gene for Red, you might get red babies when you breed red x white. If the Red happens to carry a REW gene, you could get White offspring.

The most likely result of a Red x White cross would be Chestnut, which is what a lot of people think of as the wild-type coloration. Since a lot of NZW's carry Steel, another result could be solid black. Since broken has become a popular color for NZ's, there is also the possibility that the NZW might be carrying Broken, and you wouldn't see it until you crossed it with a colored rabbit.

 

[Timmy]

OK thanks. What is steel? I have black nz bucks & red nz bucks but no nz does. I was going to look for does and was considering white does because they are more readily available. also I have cals what would the result of a black or red nz buck over a cal doe be color wise? I know it would be a mutt as far as breed goes but nz cal cross is a common cross for meat production. Also sorry if I offended anyone with the word albino

 

[Bunnylady]

Steel is one of many genes that affect the amount of black that appears in a rabbit's coat. You can only see the effect of the Steel gene on Agouti-patterned animals. On your typical Chestnut, the body hairs are banded; there is a black tip, then a band of a lighter yellow/tan color, then a sort of blue-gray next to the skin. On a Steel, there is more black at the tip, so that it nearly covers the lighter band in the middle. The Steel is much darker in color than the Chestnut, and it often has black on the belly as well.

Steel is a strange gene. Two copies of it gives you a rabbit that is totally black, just like a black self. There are other combinations with it that will look like a black self, even though the rabbit is a genetic Agouti.

As to the NZ x Cal cross, I wouldn't expect to find non-extension genes (Red) in a Cal, but the rest of it pretty much applies. The pointed pattern of the Cal happens at the same place as the REW, it's just one step higher on the ladder of dominance (if a rabbit gets a copy of REW from one parent, and a copy of the Himi/pointed white gene from the other, it'll be pointed). I even know of at least one person who got steel-colored offspring when they bred something else (I think it was a Palomino) to a Cal.

 

[Timmy]

Thanks Bunny Lady for sharing your knowledge with me. I raise cals for production purposes. My daughter shows meat pens in 4h and wanted something other than the standard white rabbits that are primarily shown around here for her project this year. That's where the reds and blacks came in. We have 4 red bucks and 4 black bucks. So I figured I'd hang on to one of each just to play around with. And see what I get. I'll probably start with putting them over my cal does. And in the meantime see if I can find a nice wnz doe and maybe a red and black. Thanks again for the help. Can you recommend any good books on rabbit genetics? Or any other sources of information on the subject? I've keep rabbits sense I was a child but never had any interest in there color genetics until now.