New Zealand Rabbit Genetics Question

caseyhust · Sep 10, 2016

I bred a new zealand white rabbit to a new zealand black rabbit. There are a couple white kits, a couple black kits, an agouti, and a steel (unless it is a blue, I can't really tell what the difference between steel and blue is). I have other whites and blacks, and I was wondering if it was possible with breeding any of the rabbits I have to get a new zealand red rabbit or a new zealand broken rabbit? does the agouti potentially have the genes to make it happen with one my whites?

CandCpoultry101 · Sep 10, 2016

hi I have breed all New Zealand coolers and breed show quality new Zealand's and silver foxes and a agouti does not carry Brocken lines or will produce Brocken babies and in order to have broken you will need a Brocken buck or doe of either color.And in order to get a red you will have to have a red buck or doe,preferably both because red is the least dominant color in new Zealand's.Black is the most dominant.i hope this helps

Bunnylady · Sep 10, 2016

CandCpoultry101 said:
hi I have breed all New Zealand coolers and breed show quality new Zealand's and silver foxes and a agouti does not carry Brocken lines or will produce Brocken babies and in order to have broken you will need a Brocken buck or doe of either color.And in order to get a red you will have to have a red buck or doe,preferably both because red is the least dominant color in new Zealand's.Black is the most dominant.i hope this helps

If I understand what this poster is trying to say, they got some of what they said right, but a lot of it is not; at least, they aren't looking at things the right way . . . especially the part in bold print above.

There are a bunch of different genes involved in rabbit coat color, which are found in entirely different parts of the rabbit's genetic code, and it is the combined effect of all of them that results in the final color of the rabbit's coat. A rabbit has the ability to make two different pigments, a yellow/red pigment and a black/brown pigment, and each of those genes has something to say about how much of each pigment is produced, or where it appears in the rabbit's coat. The only gene that could be said to be able to make a color all on its own might be the gene for Ruby-eyed White (REW). The gene for REW shuts down pigment production completely, so you can't tell what the other genes the rabbit is carrying might code for.

The gene that codes for the broken pattern comes in two forms, broken or non-broken. As you know, broken is a pattern of white overlaid on some base color. Broken is a dominant gene, meaning that if a rabbit has that gene, you will see the results - it doesn't hide. A colored rabbit can't hide a broken gene - if it has a broken gene, it will have some white on it, even if it's just a little bit of white mostly on the face and feet.

The one exception to what I said about the broken gene not hiding has to do with the REW gene. Because REW shuts down all pigment produced in all parts of the coat, it is possible for a REW to be carrying a broken gene, and it not be visible - a pattern of white on a white coat would just be white. So if you breed a solid colored rabbit to a REW and get broken babies, it's because the REW was carrying broken, not the solid. But if you breed a REW to a solid and get a bunch of babies and none are broken, you can be pretty sure the REW doesn't carry broken (I once had a REW Holland Lop doe that I bred to a Smoke Pearl buck several times. She had about 5 or 6 babies each time, and in the first two litters, all of the babies were either REW or solid Smoke Pearls. It wasn't until the 3rd litter that I started seeing Broken Smoke Pearls, and figured out that the doe carried a broken gene).

As to the colors you saw in your current litter, this is a blue:

This is a steel:

And just to make it interesting, this is a blue steel:

Steel looks a lot like a Chestnut, though the normal banding of the agouti pattern often gets reduced to light ticking, and the belly is usually dark, not pale. The gene for steel happens in the same place as the main gene for red. Steel is a weird gene; it acts differently depending on what it is paired up with; a lot of combinations can be solid black, just like a black self, even if the rabbit has agouti genes.

As to whether you could get reds from your assorted blacks and whites - it's possible, but not terribly likely. Good reds don't only need the right combination of the major genes, they also need a bunch of little "helpers" that really crank up the red pigment, and those tend to get lost when breeding with other colors. If some of your rabbits had good, red parents, it would make it more likely.

Bunnylady · Sep 10, 2016

This subject got discussed in more detail on this thread:

https://www.backyardchickens.com/t/853013/new-zealand-rabbit-genetic-question

caseyhust · Sep 12, 2016

Thank you all for your replies. I think I am slowly gaining an understanding of New Zealand genetics. And thank you especially bunnylady for the pictures. Our kit is definitely not a steel. I am fairly confident it is a blue, but if somebody who knew what they were looking at told me it was a blue steel, I wouldn't disagree. I guess my question from here would be... if I were to keep the blue and mate it with some of my black and whites, would I be able to keep getting blues? Obviously it has one white gene (c) in it, so I would get some whites out of it, and I would probably get some blacks out of it, but I kind of want to get some more of the blues (my wife and I really like the color, and we tan our rabbit pelts, so some variety to go with black and white is nice). Is the blue color just from a certain level of black genes, or is there a blue gene(s)? Would I get anything besides black, white, and/or agoutis if I kept my agouti and mated it with black and whites (and maybe a blue if I am able to breed a blue niece or nephew for it? Finally, as I mate the black and whites I have, should I expect to keep getting blues and agoutis (the first time I mated my black buck with a different white female, I only got black and whites)? The mother from the litter with the blue and agouti is getting older and I am not sure how many litters she has left in her before I should replace her

Bunnylady · Sep 12, 2016

Blue in a rabbit is not like the blue/black/splash thing in birds - it's a completely separate gene series. There is a gene, called the dilution gene, that occurs in in its own location. It is recessive, so if you get a baby that is a dilute color, you know that both parents had to have at least one copy of the dilution gene.

Dilute affects both the black and yellow pigments, reducing the amount produced and causing it to clump inside the hair shaft so the effect is a much lighter color.
Black becomes blue, red becomes fawn, steel becomes blue steel. Since you have a chestnut in your litter, here's another possible color for your mystery baby - opal.

Which is the dilute of this color, chestnut:

A rabbit that is a dilute color can only give the dilution gene to its offspring, so if you breed it to another rabbit that has even one dilution gene, you should get (some) dilute colored offspring. Whether they'd be blue, opal, blue steel, or some other color we haven't talked about, well, that would be determined by what other genes they inherited. Be warned, though - I believe my rabbits put their heads together when I'm not there and ask each other, "how can we drive her crazy today?!" One of their oldest tricks goes like this: whatever color you are hoping to get from a cross, it will be the last one you see, or it will be the baby that crawls out of the nest and dies, or the runt that you wouldn't breed for beans!

caseyhust · Sep 14, 2016

Ok. Between what you have said and reading the Tap rabbitry site, I do think I am grasping at least the theory of their genetics. This is the rabbit in question in my litter:

So, would you say that this one looks blue or blue steel? Also, one last question on the genetics: Does an agouti (A_) have to carry a steel (Es) gene? I couldn't tell based on what I was reading, and I was wondering if the presence of the agouti in the litter meant that at least one of the parents was carrying a steel gene?

Thank you so much! You have been so incredibly helpful!

Bunnylady · Sep 14, 2016

I'm thinking that the brownish tint I'm seeing on that kit is sun fading; it looks like a blue to me.

Agouti happens in the A series: there is no direct link to Es or any other allele in the E series. You can certainly have Agouti patterning without the steel gene being present - many, many breeds have agouti patterned colors. A rabbit could also have a gene for steel without having agouti genes, the only problem is, you couldn't see it.

A rabbit has the potential to produce two pigments, black and yellow. The solid black rabbit has yellow pigment in his coat, you just can't see it because the black covers it up. The agouti gene restricts the black pigment to the tip of the hair shaft, revealing the yellow pigment in a band in the middle of the hair. Steel sort of counteracts some of the restriction of the agouti gene, so you get more black and less yellow on a steel colored rabbit. On a rabbit with self genes, the black is not restricted anyway, so there is no visible difference between a self with steel, and a self that doesn't have steel.

Believe it or not, red is an agouti-patterned color. It starts with the agouti gene restricting some of the black pigment, then has the non-extension genes (ee) restricting it even more, then has the wide-band genes (ww) to push any remaining black out, plus a bunch of rufous modifiers (++++) to push the yellow/red pigment into overdrive and give you that deep brick red color.

One of the crazy things about the steel gene is that you need a very specific combination of genes in order to be able to recognize it. Not only do you need agouti at the A locus, you need one copy of steel (Es) and one copy of normal extension (E) at the E locus. There are other possibilities in the E series; namely, non-extension (e) and harlequin (ej). The only combination that is guaranteed to give you a visual steel is EsE. A rabbit with EsEs will be solid black, in appearance exactly like a rabbit with self genes (I saw somebody recently refer to this combination as a "super steel"). A rabbit with the Ese or Esej may also be solid in color, or it may have just a little bit of lighter ticking visible on its coat (similar in appearance to silver, the difference being that the ticking would be light/no pigment on only part of the hair shaft, and silvering has completely white hairs).

Because steel happens in one gene series, and dilution happens somewhere else, you can have rabbits that are both dilute and steel. As I said, your kit looks like a blue, but it is possible that it is genetically a blue "super steel." Just looking at them, it's impossible to know if your black rabbits are black because they have self genes, or black because they have steel genes, or they could even have both . . .

Eyes rolling back in your head yet?

secuono · Sep 15, 2022

Bunnylady said:
If I understand what this poster is trying to say, they got some of what they said right, but a lot of it is not; at least, they aren't looking at things the right way . . . especially the part in bold print above.

There are a bunch of different genes involved in rabbit coat color, which are found in entirely different parts of the rabbit's genetic code, and it is the combined effect of all of them that results in the final color of the rabbit's coat. A rabbit has the ability to make two different pigments, a yellow/red pigment and a black/brown pigment, and each of those genes has something to say about how much of each pigment is produced, or where it appears in the rabbit's coat. The only gene that could be said to be able to make a color all on its own might be the gene for Ruby-eyed White (REW). The gene for REW shuts down pigment production completely, so you can't tell what the other genes the rabbit is carrying might code for.

The gene that codes for the broken pattern comes in two forms, broken or non-broken. As you know, broken is a pattern of white overlaid on some base color. Broken is a dominant gene, meaning that if a rabbit has that gene, you will see the results - it doesn't hide. A colored rabbit can't hide a broken gene - if it has a broken gene, it will have some white on it, even if it's just a little bit of white mostly on the face and feet.

The one exception to what I said about the broken gene not hiding has to do with the REW gene. Because REW shuts down all pigment produced in all parts of the coat, it is possible for a REW to be carrying a broken gene, and it not be visible - a pattern of white on a white coat would just be white. So if you breed a solid colored rabbit to a REW and get broken babies, it's because the REW was carrying broken, not the solid. But if you breed a REW to a solid and get a bunch of babies and none are broken, you can be pretty sure the REW doesn't carry broken (I once had a REW Holland Lop doe that I bred to a Smoke Pearl buck several times. She had about 5 or 6 babies each time, and in the first two litters, all of the babies were either REW or solid Smoke Pearls. It wasn't until the 3rd litter that I started seeing Broken Smoke Pearls, and figured out that the doe carried a broken gene).

As to the colors you saw in your current litter, this is a blue:

This is a steel:

And just to make it interesting, this is a blue steel:

Steel looks a lot like a Chestnut, though the normal banding of the agouti pattern often gets reduced to light ticking, and the belly is usually dark, not pale. The gene for steel happens in the same place as the main gene for red. Steel is a weird gene; it acts differently depending on what it is paired up with; a lot of combinations can be solid black, just like a black self, even if the rabbit has agouti genes.

As to whether you could get reds from your assorted blacks and whites - it's possible, but not terribly likely. Good reds don't only need the right combination of the major genes, they also need a bunch of little "helpers" that really crank up the red pigment, and those tend to get lost when breeding with other colors. If some of your rabbits had good, red parents, it would make it more likely.