Breeding siblings? Your thoughts and experiences please

[AmberRae]

Does anyone have any experiences breeding brother and sister? I have 2 that are perfect type and color and would love to see what their kits would look like. Their parents were not related in anyway. I am assuming if their are any genetic defects in them it would be very prevalent in their kits. I am pretty sure I am going to give it at least one try. I will be very sad if a defect shows up. I am an emtional whimp about that stuff.

 

[Zass]

My understanding is that close inbreeding is best attempted by those who are prepared for mercy culling any recessive genetic problems that may occur. If you are OK with it, it's a good way to learn a bit more about what genes they may have unexpressed.

 

[AmberRae]

Thank you Zass that is a good perspective to look at it from. It might not be for me after all.

 

[Rainey]

I was going to post about this topic this spring. We're breeding siblings this year--not same litter but same buck and doe. We did it once before when we weren't planning to keep any breeding stock from the litter and we didn't see any abnormalities before they all went to freezer camp. By following the 'breed the best and eat the rest' guideline, we've kept narrowing our genetics. The first 2 NZW does were bred to a SF buck, so no relationship there. But one was clearly better than the other so we kept does from her to breed back to the SF the next season. For a while we had Casco and her sister Berwick, both good and we kept a buck from one and does from another to breed. But last year Berwick didn't kindle and after a couple tries we gave up on her. And Casco's kits are still the best and she's such a good mother so this year all the young new breeders are from her.
I guess we'll just continue breeding the best and eating the rest until we see a problem. Then we'd have to bring in an unrelated buck. But it seems that often brings on problems of its own and it can be complicated by the way we feed. We don't want more rabbits than we're raising now (seem to have a natural immunity to rabbitosis) so we'll always be working with just a few does and one buck. Our next litter is due Monday and that is a sibling breeding--will let you know how it goes.
And I was just thinking how thankful I am that RT is a place I can post about this without getting lectured or blamed and shamed.

 

[SoDak Thriver]

And I was just thinking how thankful I am that RT is a place I can post about this without getting lectured or blamed and shamed.

Word, Rainey.

Line breeding can be very rewarding, and can go very wrong.

Like Rainey, we do the "breed the best, eat the rest" program, but our setup used to be really small. So small, that every winter, we had to reduce to one buck and two does. Now I have 5 does and 3 bucks, but deep genetic issues. Our litters are tragedies with many kits being still born, splay leg, or even if they make it to fryer weight, maloccluded. Living where I do, I'm unable to find a source of new genetic material close enough to make the drive. I'll probably have to wait until the state fair to find new Californians to reboot my herd.

Until then, I'm mixing and matching my breed stock to try to cull our way out of this nightmare. It's not for the faint of heart. Best of luck to you, whatever you decide! <br /><br /> -- Fri Apr 06, 2018 9:06 am -- <br /><br /> The most important lesson I took from this is to eat the pretty rabbits and keep the rabbits that made the pretty rabbits. :twisted:

 

[Rainey]

SoDak, this may be a dumb question, but I wondered how the problem first arose--if it was slow in developing or if you were going along getting healthy litters and suddenly had all these problems develop at once.
One of our first does had a splay leg kit and a couple stillborns in a litter of only 6 (NZW) and we didn't keep any of her offspring to breed. I think we've seen one splay leg since in a doe's first litter and didn't breed her again. We do have occasional litters with around 8 healthy kits and one doa, often looking not fully developed but hadn't considered that a problem. I'm wondering what I should be watching for and whether I can count on some early warning signs. Thanks for letting me learn from your experience.

 

[SoDak Thriver]

It was all of a sudden, but remember, we chose our breed stock every winter, based on show quality, and the rest went to freezer camp (we had a really small space to winter the rabbits). That means that there's no trial for a new breeding pair, so we are stuck until we get some success or new genes. <br /><br /> -- Sat Apr 07, 2018 5:58 am -- <br /><br /> Out of the litters that our current breed stock came from, there were no obvious defects in any of their siblings, so pretty sudden.

 

[michaels4gardens]

I personally have had very little trouble with any sort of "inbreeding/line breeding " but - I have heard from others who have had disasters.. I once worked for an older man who had several hundred does-- all of his rabbits looked identical - they were very productive- and grew very well- he claimed that after he bought his first few rabbits 30+ years before-, - he never brought in any outside rabbits of any kind-he had a totally closed rabbitry, and no visitors even went inside...- he said about the same thing Grumpy said, -"breed your best ,ship the rest".. he kept very good records, and tattooed every rabbit he kept back for replacements ..

 

[Marinea]

I breed one set of siblings. Only a first generation, and advise buyers of the kits not to breed litter mates. This duo is very productive, and I have had no problems with the kits.

 

[michaels4gardens]

when I had a commercial rabbitry,..... I had 4 sections, - when i selected replacement bucks- I rotated the genetics -IE - bucks selected from section #1 ,-bred does in section #2, etc .... the does always stayed in their own section... so although I didn't bring in any "new blood" I had genetic diversity ... but very predictable genetic diversity ... I started out with 4 does and a buck from the man mentioned above... each doe and replacement does from her- became a section...

 

[Rainey]

when I had a commercial rabbitry,..... I had 4 sections, - when i selected replacement bucks- I rotated the genetics -IE - bucks selected from section #1 ,-bred does in section #2, etc .... the does always stayed in their own section... so although I didn't bring in any "new blood" I had genetic diversity ... but very predictable genetic diversity ... I started out with 4 does and a buck from the man mentioned above... each doe and replacement does from her- became a section...

If I had a larger rabbity I would not breed such near relatives, but I don't have and don't plan to have more than 3 or 4 does being bred in any given year. But in your case, Michael, you were starting with related does and buck from this man who had not brought in new stock for 30 years. Does that matter? Is it relevant that I started with a buck that was a different breed from my does? Or is that not as important as whatever genetic flaws the starting rabbits carry? I'm realizing more and more how very little I understand about genetics.

 

[alforddm]

Is it relevant that I started with a buck that was a different breed from my does? Or is that not as important as whatever genetic flaws the starting rabbits carry? I'm realizing more and more how very little I understand about genetics.

It's not as important as whatever genetic flaw your original rabbits carried. Say one of your rabbits carried one (we all carry some detrimental mutations) mutation with a recessive mode of inheritance. We will call it (z). So your starting buck was Zz. He carries one normal allele and one "broken" allele. Statistically, 1/2 of the kits he sires also carry the recessive z mutation but you never see it because the Dams are all ZZ so no detrimental effects appear. However, when you start keeping does from this buck and breeding them back to him (or breeding to a sibling carrier) you end up with kits that are zz. These kits maybe viable and good looking/growing rabbits but the mutation does something funny to their reproductive tract so that a high percentage of their kits are stillborn. It maybe as simple of decreased blood flow. It maybe hormonal. There are many possible scenarios some of which are potentially much more complex. There is the possibility that whatever is causing it is polygenic meaning that multiple genes are involved.

In a slightly larger herd, this probably wouldn't matter at all because the poorly reproducing rabbits would just be culled and replaced.

 

[michaels4gardens]

when I had a commercial rabbitry,..... I had 4 sections, - when i selected replacement bucks- I rotated the genetics -IE - bucks selected from section #1 ,-bred does in section #2, etc .... the does always stayed in their own section... so although I didn't bring in any "new blood" I had genetic diversity ... but very predictable genetic diversity ... I started out with 4 does and a buck from the man mentioned above... each doe and replacement does from her- became a section...

If I had a larger rabbity I would not breed such near relatives, but I don't have and don't plan to have more than 3 or 4 does being bred in any given year. But in your case, Michael, you were starting with related does and buck from this man who had not brought in new stock for 30 years. Does that matter? Is it relevant that I started with a buck that was a different breed from my does? Or is that not as important as whatever genetic flaws the starting rabbits carry? I'm realizing more and more how very little I understand about genetics.

I can't see in the dark either -- the only way we find out- is to breed them...

 

[MaggieJ]

Quite a number of years ago, there was a much-quoted study where rabbit siblings were bred to each other for 17 generations before they ran into problems. I have no way of telling how accurate was this information, nor do I have any references to quote to support it.

The thing about inbreeding and line-breeding is that they intensify both desirable and undesirable characteristics. I don't think you can really be sure what you'll get until you try it.

Like Rainey, my rabbitry was small and I rarely had more than one buck at a time. So the rabbits were quite inbred, though I avoided sibling matings because that was the conventional wisdom at the time.

In all the years I had rabbits I only brought in three new ones. One, a doe, barely made it out of quarantine and neither of the bucks thrived long-term, though both lasted long enough to contribute their genes to the mix and their offspring were fine. In a small rabbitry, you constantly run the risk of needing an import if something happens to your one buck.

 

[hotzcatz]

There's a lovely pedigree program called "Kintracks" and it's newer version "Animal Breeder" (I think that's the new name) that will track the Coefficient of Inbreeding for you. We started out with essentially six rabbits (3 of each gender) in 2009 and we're still managing to keep the COI below 25%. I don't think we'd be able to do that if we didn't have the program do all the math of who's related to whom by what percentage. https://www.kintraks.com/

It's even a free program if you're running an older computer - Win7 and older. Even should you pay full price for it, it's only $25 Australian and there's free upgrades and support forever after. I've been using it for years and it's really useful for pedigrees, tracking weights, notes, etc. etc.

 

[RebelScumHan]

I do it. My doe just gave birth to her first litter from her brother... all healthy, beautiful babies. We breed father to daughter, too. There was an experiment that showed it took something like 36 generations of inbreeding before ANY issues emerged. It's just not something to worry about and it's really one of the best ways to bring out those fantastic genetics you want.

 

[Rainey]

I do it. My doe just gave birth to her first litter from her brother... all healthy, beautiful babies. We breed father to daughter, too. There was an experiment that showed it took something like 36 generations of inbreeding before ANY issues emerged. It's just not something to worry about and it's really one of the best ways to bring out those fantastic genetics you want.

We've already bred 2 does to full siblings this spring and one doe is bred to her son and one doe to her father. I'm wondering why breeding siblings is seen as a problem by some who don't see father/daughter or mother/son breeding that way Wouldn't you have the same problem of the recessive genes manifesting in some of the offspring?
Another question--even when you have unrelated rabbits, you don't now what recessive genes they might carry and could get the same sort of problems in any given match for breeding.
Do most people bring new rabbits into their breeding programs to avoid problems associated with inbreeding or to introduce desirable traits--better markings or type etc?
Bottom line for me--we're just raising rabbits for meat for ourselves and what we have is good enough for our purposes so we'll go on as we started as long as we have healthy litters that grow out on our feed in a reasonable time.
I really appreciate all the folks who addressed this issue and hope it wasn't a hijack to take it away from (or beyond?) the original post.

 

[michaels4gardens]

I do it. My doe just gave birth to her first litter from her brother... all healthy, beautiful babies. We breed father to daughter, too. There was an experiment that showed it took something like 36 generations of inbreeding before ANY issues emerged. It's just not something to worry about and it's really one of the best ways to bring out those fantastic genetics you want.

We've already bred 2 does to full siblings this spring and one doe is bred to her son and one doe to her father. I'm wondering why breeding siblings is seen as a problem by some who don't see father/daughter or mother/son breeding that way Wouldn't you have the same problem of the recessive genes manifesting in some of the offspring?
Another question--even when you have unrelated rabbits, you don't now what recessive genes they might carry and could get the same sort of problems in any given match for breeding.
Do most people bring new rabbits into their breeding programs to avoid problems associated with inbreeding or to introduce desirable traits--better markings or type etc?
Bottom line for me--we're just raising rabbits for meat for ourselves and what we have is good enough for our purposes so we'll go on as we started as long as we have healthy litters that grow out on our feed in a reasonable time.
I really appreciate all the folks who addressed this issue and hope it wasn't a hijack to take it away from (or beyond?) the original post.

most people bring in "fresh blood" because they have been told that they need to, by "others" I have had far more genetic problems from bringing in "fresh blood" to my herd then I ever had from line, or in breeding..

 

[ladysown]

what inbreeding does is show deficiencies in your herd. IF you have any hidden genetic issues that's where you'll see it. For instance... I didn't know I had fuzzies in my herd until I started breeding father to daughter and suddenly I have bucket loads of them. TRYING to get rid of it as doing fuzzies is not what I want to do. SOME of them come out looking like jersey woolies if you look at their profile so I'm thinking someone fudged on a pedigree somewhere.

if you have any teeth problems in your herd FIX THAT before you breed inline. You don't want to fix that into your herd, along with pinched hips, curved spines etc.

Only breed that VERY VERY best of your herd to your very very best.

 

[hotzcatz]

It also matters which two siblings are crossed. If their parents aren't closely related to each other, then it's about a 25% inbred and probably not much culling necessary. I've got one buck that is the result of a sire/daughter cross but that was an intentional (as far as I'm concerned) inbreeding. I wanted to get a concentration of genes from the original buck to his replacement. If that buck from the sire/daughter cross were bred to a full sibling, the coefficient of inbreeding would be almost 60%.

When the rabbits here get too inbred, then the Vienna marks start showing up. That's a DQ on the show table, but otherwise a fairly harmless gene as far as I know.