What Color is This?

[JT17]

Trying to do my best to understand rabbit genetics. Honestly though...theres a lot to it. Can be a little difficult.
What color is this guy? He's my main buck and he is supposed to full New Zealand.

 

[Tale of Tails Rabbitry]

Gold-tipped steel. You can see the hairs are ticked with a golden color. Many New Zealand Whites are steel, but you cannot see it because all the color is removed, and some NZ Blacks are actually super steels or have two steel genes "EsEs" that extend the base color fully on the hair shaft to look like a solid black. At least one of the parents of your rabbit was a "Es_" steel to pass on the gene. It is a dominate gene so if you have steel, you are likely to see it on the agouti rabbit....unless it has a non-extension gene along with it as in "Ese" which may or may not show any ticking anywhere. You also will not see steel on a self rabbit having "aa."

If you are curious about the genotype: A_ B_ C_ D_ EsE
A - agouti
B - black
C - full color on coat
D - dense color (not diluted)
Es - steel
E - full extension

 

[JT17]

Any recommended reading for better understanding genetics? Im wanting to have a better chance at predicting the colors of kits for my breeding program

 

[Tale of Tails Rabbitry]

I have read lots of sites on the Internet, but not all the information is accurate on some. Between those sites that really messed me up with trying to understand steel in particular and the ever patient and helpful Bunnylady teaching me right here on this board, I finally got some it through my thick head. It took months though.

Also, the more you learn about color genetics, the more you realize that the hidden recessives are going to make predicting really hard and yet the more you learn the better you get at understanding the possibilities or what you are seeing in your nesting box and why...and then there is how rabbits are pretty unpredictable regardless of what you think you know, because they are rabbits.

I am not an expert, but like you my interest was piqued when I was cross breeding NZWs and Silver Foxes getting all kinds of crazy patterns and fur colors. My first GTSs were not as golden as yours is, far darker actually, but my last one was quite golden: Same dam, different sire. You will come to understand that there are modifiers that control this that we do not yet understand, but we know they have to be there somewhere. In fact, I know someone who specifically breeds for steel and is a wealth of information on the subject, where most breeders specifically try to avoid steel.

So about genetics...let me walk you through an easy one that I wrote up for a FB Silver Fox group new to genetics, but you should be aware that even though I discussed chocolate and it is a color seen in my breed (although not highly desired), chocolate should not be in New Zealand lines (...and yet I have seen some chocolate NZs):

There are many ways to begin explaining genetics, but I thought that it might be helpful as an introduction to start with the simplest, the B-locus. A locus holds two alleles, one from each parent. The B-locus can only have two alleles that are symbolized as "B" and "b". The most dominate is written as a capital letter and recessives are written as small letters. Since the B-locus has only two possible alleles, this is simple, but there are other loci (plural for locus) that have more than just two possible alleles and an order of dominance (and even some alleles with co-dominance).

The B-locus is the base color.

"B" stands for black based (blue is also black based, more later)
"b" stands for chocolate based (lilac is also chocolate based, more later)

Every variation in rabbit coat colors are either black or chocolate based.

There are three possible combinations on the B-locus:

BB - homozygous black (two same alleles)
Bb - heterozyous black (two different alleles)
bb - chocolate, which is always homozygous

Then there is this:

B_ - black with unknown second allele

Since "B" is dominate, much of the time you will see the genotype written as "B_" because the second allele may not be known even if the colors of the parents are both black based.

In other words, if the rabbit is black based, it will have at least one "B" and one "B" is all it takes to make it a black based color.

If just one parent is "BB" then it can only contribute a "B" so all the offspring will have a least one dominate "B" making all the offspring a black based color. However, the other parent could be "carrying chocolate", another way to say it may be "Bb" or may be a heterozygous black. You will not know for certain which of the offspring is "BB" or "Bb" without test breeding, which is why it would be written "B_" even if both parents were black.

Recessives like "b" hide so it takes two recessives on the locus to be seen. Unless one parent was chocolate "bb", you will not know if "b" is carried by a black or not, with certainty. Test breeding is often done to bring out the second allele. If any offspring is chocolate out of two black parents, both parents must be heterozygous blacks having "Bb" because the only way to have a chocolate based color is if there are two recessive "bb" on the B-locus, one from each parent.

A test breeding usually is done with a rabbit known to have recessives and may be like this:

Black "B_" x Chocolate "bb"

If there is ANY chocolate offspring, the black parent is "Bb".
If ALL the offspring are black, it MAY be that the black parent is "BB" and future breedings would still be needed to confirm.
(By the way, all the black offspring from this breeding will be heterozygous black "Bb".)

Just so I know I explained well enough for everyone to get it (you can look above for the answers):

1. Which is dominate "B" or "b"?

2. Is "BB" homozygous or heterozygous?

3. What colors are the following?
BB =
Bb =
B_ =
bb =

4. If you breed two blacks together, what could be the possible base colors?

5. What genotypes and colors are possible with:
For instance, BB x BB = only BB blacks
BB x Bb =
Bb x Bb =

Now try this one last one for extra credit:
Can two chocolate based SF rabbits produce black based offspring?


JT17, if you can get this much, then I might know where to send you, but for the most part there are quite a few alleles that you should be aware of yet not see on a New Zealand, which is why learning color genetics more specific to your breed is a bit easier. I will post the answers for you to see how you did.

 

[Bunnylady]

Any recommended reading for better understanding genetics? Im wanting to have a better chance at predicting the colors of kits for my breeding program

What is your goal with your breeding program? If showing is your goal, you are far, far better off breeding rabbits of the same color together. Yeah, I know, that's boring, but mixing colors up can result in a lot of non-showable colors, like your Steel buck. To get the white, you just need two copies of one gene - the Ruby-eyed White gene - but REW's tell you nothing about the other genes they carry, and you can get some real surprises when breeding to them. Red requires a specific combination of several genes, and if you outcross Red to some other color, it can take several generations (and a lot of luck!) to get back to "good" Reds.

If selling breeding stock is a goal, once again, keeping colors to themselves is still the best plan. Some people may know that New Zealands come in Black, Red, White, Blue, and Broken, but if they see things like Tort, Steel, Fawn, Opal, etc, they may not believe they are looking at purebreds, and be only willing to pay mixed-breed prices (and possibly have doubts about your honesty!)

 

[Pastor Dave]

Things are definitely changing all the time. Things changed sooooo much in the 20 year break I took from rabbits before starting back up. I had never heard of a broken pattern rabbit like you may get in crossing NZW and NZ Blacks. We had them, but they wouldn't have qualified for showing. I dive back in a few years ago and sooooo many recognized colors that breeders attempt to get. New breeds too. It used to be pretty simple. Not necessarily better, but simpler.

 

[Tale of Tails Rabbitry]

Things are definitely changing all the time. Things changed sooooo much in the 20 year break I took from rabbits before starting back up. I had never heard of a broken pattern rabbit like you may get in crossing NZW and NZ Blacks. We had them, but they wouldn't have qualified for showing. I dive back in a few years ago and sooooo many recognized colors that breeders attempt to get. New breeds too. It used to be pretty simple. Not necessarily better, but simpler.

@Pastor Dave I get that. I used to think that broken was the natural combination of a solid color like black and a REW, when I was finding them from crossing NZW and Silver Foxes, however--and this is for anyone reading this that may not know how it works--the broken gene is dominate and always shows itself, except on a REW that would hide it. So the REWs are carriers of the broken patterns not seen until bred with something other than another REW.

And, colors and new breeds are not the only thing that has gotten more complicated. Actually, I am in the midst of conversations about how some top breeders have become quite focused on the top lines and are changing the commercial body type to be quite unnatural and unbalanced looking. My breed, Silver Foxes, were changed from their original mandolin body type to "New Zealands with Silver Fox fur," as I call them sometime before or around the 1990s. Now it is swept into how some top show breeders are going for a higher peak farther back over the hip joints with ALL commercial class breeds, which makes me a bit concern about crippling, stressing the back legs and hips, or perhaps causing complications with kindling.

In all honestly, it was so much easier when I just raised rabbits just for meat and furs.

 

[JT17]

@Bunnylady my breeding plan is to get breed stock and eventually show (not completely sure on that yet). Right now I raise them for meat and breed stock. So it probably would be a good idea to raise them to one color.
I have a line of REWs that i keep going, but thought it would be neat to see what tho buck with my REW doe throws as far as colors with kits. She just kindled a week ago. Cant tell the colors just yet but only one of the 6 is going to be white.
@Tale of Tails Rabbitry those are some good ones. Made me think. What are the answers?

 

[Tale of Tails Rabbitry]

@JT17 You should post pictures of your kits so we can help you ID the colors and help you with the genotypes of your breeders! However, if you have one kit that is a REW then your GTS buck is A_ B_ Cc D_ EsE, because a REW kit has to have "cc" and each allele must come one parent. You may have known the REW doe has "cc" because that is what makes her a REW, but you may not know that the buck carried "c" (unless one of his parents was a REW) because it is a recessive (small letters are recessives) which is not seen when there is a more dominate allele on the same locus, as in this case. The capital "C" is dominate and stands for full color. The "c" is recessive and stands for the inability to express any color. The C-locus is unlike the B-locus, because it has five possible alleles not just two, but only two can fit on the locus. Also, the other three should not be in the NZ genetic make-up, so unless you get something funky, you really only need to know that "C" is color turned on and "c" is color turned off or white. Under the "cc" REW can be a black, blue, red, steel, or even broken that is not expressed because of the REW removes all color.

You probably now realize that what I wrote previously on the B-locus is just a taste of rabbit genetics and one of the easiest loci to learn, but as I said most websites and books teach ALL the genetics, which can be so overwhelming and most would be irrelevant to New Zealands. On the other hand, NZs have colors that are not (should not) be found in my Silver Fox breed, like red. Also with steel in play, it gets very, very complicated and there is a lot of flawed information on the Internet on it.

I believe that the American Rabbit Breeders Association (ARBA) currently recognizes these colors for NZ: red, black, blue, broken (those colors mingled with white), and white. You should consider joining it and getting the Standard of Perfection book, if you are planning to show--do not get the e-book because if you need to ever change computers they will not provide a second key without buying another one (ask me how I know ) Notice no chocolate, so that "b" allele should not be in the NZ because most breeders would have worked to breed it out upon any discovery of it.

So here are the answers:

1. Which is dominate "B" or "b"?
The capital letter "B" is dominate.

2. Is "BB" homozygous or heterozygous?
Homozygous.

3. What colors are the following?
BB = black
Bb = black (carrying chocolate)
B_ = black (with unknown second allele)
bb = chocolate

4. If you breed two blacks together, what could be the possible base colors?
black and chocolate

5. What genotypes and colors are possible with:
For instance, BB x BB = only BB blacks
BB x Bb = BB blacks and Bb blacks
Bb x Bb = BB blacks, Bb blacks, and bb chocolates

Can two chocolate based SF rabbits produce black based offspring?
No, bb and bb cannot produce B_.

 

[JT17]

Heres some pictures of the kits. The one that died was pink skinned. It died at birth though.