death by color?

[luvabunny]

Out of a litter of 10, I have 4 survivors.
One was born dead, and 5, all broken blue, died between 3-4 weeks old, one right after the other.
The surviving siblings are 2 solid blue and 2 broken blue torte.

Is there such a thing as a lethal color gene?

The breed is English lop. Parents are totally unrelated.

Mama is REW with the following colors in her background, starting with parents first - blue steel, bkn blk torte, REW, sable, orange, bkn blue torte.
First time litter but they were out of the nestbox and eating on their own pretty good.
Papa is bkn blue torte with blue torte, bkn blue, blk torte, bkn black torte, bkn blue torte and bkn opal in his background. He nearly always throws me blue tortes and whatever color Mama has on her side.

I just found it very odd that all the lost bunnies were the same color, and died 1 at a time within a week of each other.

Before death, all appeared to be eating, drinking, pooping and acting normal.
I would go out in the barn each morning and find another dead. Once the last bkn blue died, all 4 of the remaining babies have been healthy and active.

I've already bred Mama back to the same Papa to see if it will happen again. Anyone ever heard of a lethal color gene in rabbits?

 

[akane]

There isn't a true lethal gene but sometimes the broken gene does seem to increase the risk of some problems. Usually though only in it's homozygous state(charlies). Did you breed 2 brokens together?

There are many other sudden death causes. Bad feed, bad hay, cocci, a few bacterial infections that might not show symptoms until too late....

 

[Miss M]

Very odd... the only color genetic combo I've heard of that causes death more often than normal is Charlie, which is two copies of the broken gene. They end up with very little color at all, and can have internal defects that kill them.

Ah, Akane beat me to it!

 

[luvabunny]

No charlies. As I said, Mama is a REW out of a bkn and a solid and Papa is a bkn out of a bkn and a solid.
All of the bkn blue babies were very heavily marked, with very little white. The ideal color pattern for bkn Elops.

Papa has never thrown me a charlie, even when bred with another bkn.

And two of the surviving bunnies are bkn, only they are bkn blue torte, instead of bkn blue.

Mama is out of a completely different line. Outcrossing about as far as you can go. Almost all of my other does are at least somewhat related to Papa, and I've never had this issue. Just makes me wonder about the genetic compatibility. Gonna give it another shot and see what happens.

 

[PSFAngoras]

If momma is a REW she could easily be hiding broken. It is possible that the kits are true Charlie's, but with heavy patterning.

 

[MamaSheepdog]

:yeahthat: To determine if your REW is a broken, breed her to a solid colored rabbit and see if you get any broken kits.

I'm sorry you lost the kits. Once they get past about a week old, I always consider them "safe" so when an older kit dies it is always more of a blow.

I hope the next litter does better. :clover:

 

[luvabunny]

Yes, she will be bred to a solid buck after this upcoming litter.

I purchased her for her butt! Her ears aren't spectacular, but she's got a fantastic loin and rear. Was hoping that would help my apparently narrow, somewhat hollow line I have now.

I have since purchased a monster buck out of my same, original lines. He is solid, and also built like a brick wall, so that will be her next mate. Any brokens out of those two, and I will know for sure.

 

[Peach]

I actually got more solids from a Broken x Broken breeding than my Solid x Broken breedings LOL and I got no charlies, but really light pattered brokens and enough color in the whisker bed. Both are heavily marked brokens, but I just have gotten lucky breeding the same doe to two different brokens and getting really light patterned brokens. Haven't had issues with them dying, but haven't kept any for show/breeding.

But breeding your REW to your solid will hopefully let you know if she is genetically broken or solid.

I wouldn't be too worried about color though,if you are breeding for show, type is what really matters. So hopefully your combinations will give you exactly what you want for your herd

 

[ladysown]

I've had does in the past that any kits of a certain colour always die before 5 weeks of age. ALL their other kits would be fine, just the ones that are a certain colour.

So yes, can colour affect mortality rates?

I believe so.

 

[luvabunny]

The color itself isn't really important, since color is not an issue for elops. They show only as solid or broken. I don't breed for color at all.

My main concern is that if this particular cross will produce non viable bkn blue babies each time, I am wasting my time making it. I purchased this doe on purpose to breed specifically to this buck.

While I believe breeding her to the solid blue buck I have since purchased will likely also produce good quality show bunnies, I've just never had the problem of all bunnies of a certain color dying.

I know there are lethal color genes in horses, dogs and birds. I just hadn't ever heard of it in rabbits. Thank you ladysown for confirming that someone else has also observed this.

Hopefully, I can prove it, at least to myself, with the upcoming litter. You can bet that if there are any bkn blues, I will be keeping a close eye on them, and maybe even removing 1 or 2 to a different Mama to see if that changes anything. I'll keep this thread updated with what I find out. She should be due mid Feb.

 

[ladysown]

Let me be clear.

I don't think there are lethal colours in rabbits... BUT.. based on observation over the past 9 years of active breeding and observation...(as opposed to just breeding when I was a kid).

I've noticed that some buck/doe combinations don't work well when producing bunnies.
Some colours don't work well off certain does.
Some bucks may appear to be healthy, but their offspring, regardless of what doe they are bred to are not thrifty.
Some does produce kits that half the litter will thrive and half the litter will fail miserably.... and sometimes the division is based on colour.
Some does will appear healthy and yet their kits fail... EVEN IF fostered to another doe, and if the bad doe fosters, those fosterees will do just fine.

Genetics are odd things.
Sometimes we just can't predict what the outcome will be and it's NOT just colour that genetics affect.

I'd breed the doe again just to see if it was a fluke or not. You may or may not wish to foster out the broken blues to another doe to see if it's a deficiency somewhere in the line.

 

[skysthelimit]

Let me be clear.

I don't think there are lethal colours in rabbits... BUT.. based on observation over the past 9 years of active breeding and observation...(as opposed to just breeding when I was a kid).

I've noticed that some buck/doe combinations don't work well when producing bunnies.
Some colours don't work well off certain does.
Some bucks may appear to be healthy, but their offspring, regardless of what doe they are bred to are not thrifty.
Some does produce kits that half the litter will thrive and half the litter will fail miserably.... and sometimes the division is based on colour.
Some does will appear healthy and yet their kits fail... EVEN IF fostered to another doe, and if the bad doe fosters, those fosterees will do just fine.

Genetics are odd things.
Sometimes we just can't predict what the outcome will be and it's NOT just colour that genetics affect.

I'd breed the doe again just to see if it was a fluke or not. You may or may not wish to foster out the broken blues to another doe to see if it's a deficiency somewhere in the line.

I believe this too. Dilutes are reported to have issues if bred dilute to dilute for generations. I don't know. But I do know that some bunnies just don't work well together, and then some does, just don't do well. Every litter I had from a particular chin doe, died before they reached 14 weeks. A beautiful doe, but I culled her.
A castor doe had a successful litter with her breeder, but had three litters with me that died because she was on day 3-4 before she produced milk.

 

[akane]

Color has actually been found to impact chemicals and neurotransmitters in the brain. They did a study on gerbils and certain colors caused certain brain patterns. Several neurotransmitters also reside in the digestive tract like serotonin and can effect digestive health. So yes color can sometimes have other effects we don't normally see and maybe when you combine 2 rabbits carrying a specific set of modifier genes with a certain color you can lose kits. Personally I haven't seen it in rabbits. It's been pretty arbitrary which kits or litters are lost. Last litter that I lost some on was a black, broken black, and 2 broken sables. I lost a broken sable and a broken black. I have had trouble with small rodents. Certain colors from certain pairings coming out aggressive, poor breeders, or not surviving at all. It's not technically a lethal gene but just a bad combo between male and female.

 

[luvabunny]

Well, I guess we'll see with the next two litters.

She is due 2/12 as a breed back to the same buck where she lost the 5 bkn blue babies. If it happens again, I will never rebreed her to him.

After those babies (or lack thereof) I will be breeding her to the solid blue buck. If there is no success with him, she will be looking for a new home. I truly don't like REW rabbits anyway, and she just doesn't have the personality to make me get attached.

She was a first time Mama, but I couldn't find anything to make me believe it was her, or her lack of care, causing the babies death. The ones that died were the same size, eating as well, as active, and appeared as healthy, as the ones that lived. I do believe there was something going on I couldn't physically see, such as a genetic deficiency. I can't explain anything otherwise.

There are no predators in the rabbitry, nothing wrong with the feed or hay, no known intestinal distress of any kind, the bunnies died with clean bottoms, dry noses, and clear eyes. Every other rabbit in the barn, including other babies, and their littermates, is doing well. Just the bkn blues of this one litter. I have bkn blues from the same Papa and a different Mama who are doing fine. Weird.

 

[concreteblonde]

Out of a litter of 10, I have 4 survivors.
One was born dead, and 5, all broken blue, died between 3-4 weeks old, one right after the other.
The surviving siblings are 2 solid blue and 2 broken blue torte.

Is there such a thing as a lethal color gene?

The breed is English lop. Parents are totally unrelated.

Mama is REW with the following colors in her background, starting with parents first - blue steel, bkn blk torte, REW, sable, orange, bkn blue torte.
First time litter but they were out of the nestbox and eating on their own pretty good.
Papa is bkn blue torte with blue torte, bkn blue, blk torte, bkn black torte, bkn blue torte and bkn opal in his background. He nearly always throws me blue tortes and whatever color Mama has on her side.

I just found it very odd that all the lost bunnies were the same color, and died 1 at a time within a week of each other.

Before death, all appeared to be eating, drinking, pooping and acting normal.
I would go out in the barn each morning and find another dead. Once the last bkn blue died, all 4 of the remaining babies have been healthy and active.

I've already bred Mama back to the same Papa to see if it will happen again. Anyone ever heard of a lethal color gene in rabbits?

I found a ppt. presentation on inheritance types. It covers both human and animal.

It speaks of Lethal Alleles.

"Many lethal alleles prevent cell division

Some lethal allele exert their effect later in life
Huntington disease
Characterized by progressive degeneration of the nervous system, dementia and early death
The age of onset of the disease is usually between 30 to 50

Conditional lethal alleles may kill an organism only when certain environmental conditions prevail
Temperature-sensitive (ts) lethals
A developing Drosophila larva may be killed at 30 C
But it will survive if grown at 22 C"

I don't believe it is just color that kills, but the other mutations that go along with the specific color. Such as Sickle Cell Anemia in black people. There are blood disorders among Indian tribes that don't affect any other person or known tribe.

So, I don't think it's the color, but the mutations that ride along with the color of that particular animal or human.

Just my two cents.

 

[Prisma]

When I had English Lops, at that age, unless the kits where removed or the cage space was very large and there was no nest box in with them still, I lost kids. Moms would jump in and inadvertently swish them, was just trying to be a good mommas but doesn't work out that way when landing directly on top of kids causing internal injury. So there's that possibility too. 2 kits are less likely to get stepped on than more.

 

[luvabunny]

Yes, I guess lethal alleles is more of what I was leaning towards. Not necessarily the bkn blue color itself, but the allowance of deficient genes which show themselves in this specific cross causing this specific color.

Obviously, the cross itself isn't lethal, as there are still 4 very healthy, very happy babies from it. However, like in horses and dogs, certain colors promote certain genetic deficiencies.

Pretty much everyone knows not to breed the Impressive horse bloodlines into certain mares, and not to breed two merle dogs together. It's not the color of the animals themselves, but the color the gene produces when they are crossed which increases the likelihood of blindness, deafness or even death.

At the point the bunnies were being found dead, they were out of the nestbox and it had been removed. My cages are 24 x 36, so plenty of room for Mama and nine 3 week old babies. Grass hay in the floor of the cage, so plenty to munch on and for cushion / warmth. I truly do not believe Mama had anything to do with the deaths. Generally if Mama is getting sick of the babies, one finds marks, etc on other babies as well. None have been found.

 

[concreteblonde]

How are the rest of the bunnies doing? Everything still okay?

 

[luvabunny]

The four remaining bunnies are doing fine. They will be 8 weeks old soon. All 4 greet me at the front of the cage and love to climb onto my arms and lick my hands and nose. Such sweet little things.

One is going to be the star in a magic show this upcoming weekend. Gramma is a professional magician and has visiting grandkids she wants to put on a show for. Renting the bunny for a Saturday. It will be returned in less than 6 hours.

Never to early to begin earning their keep!