A Black is not a black?!

[CO Int]

Hi everyone

I've got quite a complicated color issue. So far I have very few test breedings and no self color rabbits (that I know of) to test some of my theories so I've been spending a lot of time on the genetic calculator. :lol:

I breed a local South African rabbit breed that was developed from a large base of genes. Some of the ancestry includes Flemish Giants, New Zealand, Rex, Satin, Silver Fox, Chinchilla and maybe some angoras in between as well.

The breed standard only recognizes three colors - agouti, black and steel. Originally any chocolate and blue lines were removed, but they are looking to introduce the colors back in.

Steel is extremely dominant in the breed and therefore without test breeding very difficult to determine if a rabbit is black or super steel. However, I've noticed a lot of silvering/scattered white hairs on the "blacks". I have a doe that is black with scattered white hairs but has produced several black, agouti and steel kits. This makes me wonder if she is an agouti non-extension steel or a self black carrying steel. Is there any way to know? If I could find a self rabbit I might be able to answer my own question - what breeds are typically self colored?

Here is a very standard looking black. They don't really appear black. He is a 12 week old buck. I know he still has a baby coat - but he kind of demonstrates my question as I have older does that show the same kind of coloring. He doesn't really look black. He has some scattered white hairs but his fur appears brown. I didn't keep him to breed so I have no idea if he carried the steel gene but his father is a true agouti (A_ B_ Cc D_ E_). His mother is (__ B_ Cc D_ Es_)

Then I have this doe who parents were both steel. I'll breed her in a few months and should know more about her then but I'm wondering if silvering could be an issue here? These scattered white hairs are just too regular to be scattered for my taste and they are becoming more obvious as she gets older (she's 6 months now). The hair is also very thick at the base and very thin at the tip - the entire hair is white.

Just as I was starting to think I had steel sorted in my head the silvering thing popped up. Originally I didn't even consider silvering until I found out that the Silver Fox was part of the base genetics. With co-dominance being possible is it another variation on top of everything in the mix? I have 6 "black" rabbits of which only this one doe is showing a consistent kind of patterning - the others definitely appear like scattered white hairs - random and you can count them on one hand.

There have been several people both locally and internationally involved in the color genetics of this breed but it seems most people seem stumped. Some have suggested that they are dominant black (Ed) but if they were would all of them be black? Also, how does that tie in with the rabbit not actually appearing black?

Any help is appreciated - I will not give up until I understand color genetics!

 

[ladysown]

could they be self-chin?

That's what's been suggested to me with my black kits that aren't really black.

 

[CO Int]

I've been playing with the Kim's hutch Calculator and interesting I do get a lot of breeding possibilities that are close to what I'm getting IRL.

So maybe self chin is the what's happening here. Eventually I guess if a chin pops up I'll at least be able to confirm that one.

Have to edit: I found a couple of pictures of rabbits that are seal that look very similar to mine. My rabbits are on wire floors with no urine pooling possible and are never exposed to the sun but they definitely have a brown tinge to their coat which is amplified by the flash from the camera - I don't think I've had a true black yet but will compare them all to see if I can see a shade difference. But this doe cannot produce seal with an chestnut buck. So self steel seems to be a more likely answer.

 

[ladysown]

I always struggle with loading image. This is what I get in one of my litters. They look either very black or kinda chocolatey without being chocolate. Some get ticking as they mature.

 

[Zass]

White markings, like silvering and scattered white hairs are not at all connected to a base genetic color and can appear over any pattern.

 

[CO Int]

She is certainly very pretty! I'll just take a uneducated guess and say she is a chocolate GTS. Either way I wish my babies were such a pretty color!

One of the things I've been learning about genetics is that all genes work in sequence and what one does doesn't necessarily affect the other.

It took me a while to understand that alleles are on different locations and you have to deal with the whole ABCDE...

So I understand that silvering and scattered white hairs has nothing to do with color and I didn't write it very nicely but I have two separate questions:
1. Is the picture I posted of the buck a black or not? It definitely is not a super steel but could possibly carry the steel gene.
2. Can the white hairs be silvering, scattered white hairs or is it a possible super steel? Or all three?

 

[ladysown]

i would suspect he's black once he matures. kit colour can be weird. I don't know about the silvering and how those genetics play into it all.

 

[hotzcatz]

https://web.archive.org/web/20170912070600/http://www.oceansideangoras.com/silvering-in-angoras.html

Very good article on the silvering gene. I don't think Oceanside has their website anymore, but pulled this up on an internet archive page.

I'm still trying to figure out what color this rabbit may be. She should be black but there's that patch of chocolate on her head. In an angora, the black dilutes to silver gray when the 'wool' gets longer. So the 'gray' body color is actually black and it is normal for it to be the silver color instead of black. However, that chocolate patch on her head is a complete unknown.

As a kit she was a very dark chocolate, I'd thought perhaps she was sable, but she can't be sable due to her parents. Maybe some sort of mutated black?

 

[MissMuja]

I got the exact same question then you for my "non black" kits.
I crossed a Californian buck with a NZ broken red and got 9 kits, but only black or broken black kits, where I was expecting Chestnut and broken chestnut. Now that the kits are 2 months and a half, I see some brownish color, almost like dark chocolate or Gold Tipped Steel.

I also have a New Zealand broken black that I crossed with a NZR and the Californian (I should have not do both for the same litter), at first I thought the kits were all black and that the NZR was maybe too young, but now that I worked the fur in daylight, there is again dark chocolate and broken dark chocolate, some with white tipping.

So I wonder if my NZ broken black and my Californian might have the steel gene to explain those non black / dark chocolate kits. I will try to put a picture of the pelt, with the contrast, the dark chocolate shows a lot, but it is darker in real.

 

[Zass]

Steel seems to be very common in new zealands, californians, and many other breeds. The red is the only one mentioned who absolutely could not have steel, but could still throw it if paired with a rabbit that has steel genes. It's a tricky gene that can make rabbits look from "all the way black" on one side of the spectrum, to "almost chestnut" on the other.

 

[hotzcatz]

Whatever made the chocolate patch on the black doe's head seems to not have survived to her adult coat. She's now a regular black rabbit, although she never did grow out the 'furnishings' on her head and ears. She's supposed to be a lot fuzzier than she is. Not any of it particularly matters, though, since she's not going to be a breeder. I don't think she is an improvement on what an English angora should be, so she won't be part of the breeder herd. Still dunno why she had the chocolate on her head, though. <br /><br /> __________ Fri May 07, 2021 1:45 am __________ <br /><br /> Well, now I've changed my mind and she will have one test mating with the albino buck to see if maybe she is a dark sable and has the light chinchilla gene. If she does, it should show up if she's bred to an albino.

The nice thing about rabbits is they can be bred quickly. It won't take long to find out if there's a genetic reason for her to have had a chocolate head as a kit. Otherwise, maybe somebunny peed on her head as a kit? Would that bleach black to chocolate? Personally, I'd expect it to bleach to blue, but rabbits can do the strangest things.

 

[Cosima]

Maybe the red-brown is because of the sun but I’m not sure since the reason I know is because of cat research. I assume that it’s for all animals.

 

[reverie]

Hi everyone

I've got quite a complicated color issue. So far I have very few test breedings and no self color rabbits (that I know of) to test some of my theories so I've been spending a lot of time on the genetic calculator. :lol:

I breed a local South African rabbit breed that was developed from a large base of genes. Some of the ancestry includes Flemish Giants, New Zealand, Rex, Satin, Silver Fox, Chinchilla and maybe some angoras in between as well.

The breed standard only recognizes three colors - agouti, black and steel. Originally any chocolate and blue lines were removed, but they are looking to introduce the colors back in.

Steel is extremely dominant in the breed and therefore without test breeding very difficult to determine if a rabbit is black or super steel. However, I've noticed a lot of silvering/scattered white hairs on the "blacks". I have a doe that is black with scattered white hairs but has produced several black, agouti and steel kits. This makes me wonder if she is an agouti non-extension steel or a self black carrying steel. Is there any way to know? If I could find a self rabbit I might be able to answer my own question - what breeds are typically self colored?

Here is a very standard looking black. They don't really appear black. He is a 12 week old buck. I know he still has a baby coat - but he kind of demonstrates my question as I have older does that show the same kind of coloring. He doesn't really look black. He has some scattered white hairs but his fur appears brown. I didn't keep him to breed so I have no idea if he carried the steel gene but his father is a true agouti (A_ B_ Cc D_ E_). His mother is (__ B_ Cc D_ Es_)

Then I have this doe who parents were both steel. I'll breed her in a few months and should know more about her then but I'm wondering if silvering could be an issue here? These scattered white hairs are just too regular to be scattered for my taste and they are becoming more obvious as she gets older (she's 6 months now). The hair is also very thick at the base and very thin at the tip - the entire hair is white.

Just as I was starting to think I had steel sorted in my head the silvering thing popped up. Originally I didn't even consider silvering until I found out that the Silver Fox was part of the base genetics. With co-dominance being possible is it another variation on top of everything in the mix? I have 6 "black" rabbits of which only this one doe is showing a consistent kind of patterning - the others definitely appear like scattered white hairs - random and you can count them on one hand.

There have been several people both locally and internationally involved in the color genetics of this breed but it seems most people seem stumped. Some have suggested that they are dominant black (Ed) but if they were would all of them be black? Also, how does that tie in with the rabbit not actually appearing black?

Any help is appreciated - I will not give up until I understand color genetics!

I know nothing about SF but have delt with steel. Black can look a bit brown like that - due to sun, humidity, or urine stain. I would suspect steel/super steel for the scattered white hairs like that. But I also don't know about silver fox genes and how they express, if they come into play with that

 

[CO Int]

I've been wanting to write for ages on this saga of mine - which has turned into a very complicated issue. I can't reply from my home PC as my IP address is South Africa and we are on the baddie list, so it's driving me nuts.

I breed a locally developed rabbit that has excellent feed conversion and great heat tolerance. This rabbit breed is on the brink of extinction, with only 30 original does and 4 original bucks left. I guess most people would ask why bother but as meat production animals they are unsurpassed. Their average weight is about 11 pounds but they only eat about 2 oz of pellets. Not per pound - per day. They have an incredible food conversion ratio. They can also tolerate heat well into triple digits.

I have 3 full sisters (father was GTS and mother was GTS) that all appeared black. They were however not super steels. The tipping was very visible and I didn't see one of the three that looked like a self. After playing around with the idea that they might be seal, a self chin or anything else under the sun, I've been able to go back in the pedigrees (and visit those rabbits that are still alive) to see what is happening. I have also been able to test breed all three girls to a chestnut agouti buck (who carries REW) and they produced GTS, chestnut agouti and blacks.

After searching far and wide it seems that the self gene doesn't exist in this breed anymore, so a self is highly unlikely. In the development of the breed Flemish, Chin and NZ was used so it left a wide range of other options. But none of the normal color combinations made sense. After conferring with some world class geneticists the most likely answer seems to be a modifier that is linked to the extension gene - (most likely ED from English spot which was also used in the development of the breed). It turns the gold so dark that it appears black. But, to make things more complicated, I realized there was some physical issue in these rabbits as well. Our black (and only the black) rabbits had scoliosis and kyphosis. It was developmental - it only developed after 6 weeks of age over a period of months. After going back several generations it seems that all of the affected rabbits had a specific grand sire - who was black, and most likely carried some genetic mutation which was getting more and more concentrated in the subsequent generations.

The doe in the picture was a perfect example. Her father was a chestnut agouti - mother is the doe in the picture with the silvering. She was 6 pounds at 9 weeks and 11 pounds at 6 months. But something was up. I had her slaughtered and not only did she have a very bad spine but she was also very bendy. I could almost touch her neck to her backside. Poor girl. I had a lot of hope pinned on her because of her excellent growth, but it was not meant to be. The experts can't really decide how the modifier affects the connective tissue development, but the closest explanation is like charlie in broken.

We are now slowly eradicating all black rabbits from the breeding herd, but with such a small number left it's not easy. Also as an additional stumbling block is that chestnut agouti can be carriers but the effect can only be seen on rabbits that carry the steel gene.

I'm pretty sure that this is not what most people have when they are dealing with the question of black rabbits but it's been a huge learning curve. It has taken me and several other breeders months to figure this out. We finally have an answer, but the solution is a long drawn out one.

 

[hotzcatz]

Fascinating that one ancestor could have such impact.

Seems you could inbreed to destruction and see if there's any survivors? That may get rid of the gene, but there'd be a lot of culls.

It can be very hard to eradicate a specific gene in a small herd. Do you try to keep the level of inbreeding below a certain number?

 

[CO Int]

We are following two distinct breeding principles.

The first one is exactly that - we are breeding for destruction. So far we have had about 47 culls out of 61 rabbits. It's painful and a long waiting game. But we are doing it to maintain a pure line. It's so frustrating that we can't see the feed conversion because it's so easy to lose.

We are also introducing new blood from NZ red as we have seen that the rufus in the Reds override the modifier and in turn produce proper gold tipped steels (still waiting to see what wide band will do in the long run). We also lose coat quality and feed conversion, so we have to go back to our "destruction" line to cross back to. Hopefully after our detour we will have about 75% of our genetics back minus the unwelcome modifier. But I think it will likely take at least 4 generations after that before we have cemented the breed again.

I've also used a Rex doe that has an excellent top line and is also proving to be great in feed conversion - she gets fat on air. It's just another angle but her babies are not old enough to see if they make will make weight. They do have excellent coats though so there is potential.

Our first cross babies are showing excellent improvement (hybrid vigor and all that) and we have some really stunning youngsters out of our destruction line for them to go back to. I'd have to wait for those to grow up to see if they retain the feed conversion ratio. It's a long term project but I am thoroughly enjoying it.