Line breeding- how far is too far?

[PSFAngoras]

I started out being completely against line breeding. I've learned a bit since, and now I don't see anything wrong with a single line breed here or there, or perhaps half brother and sister, but how far is too far?

I didn't see the pedigree on the champagne doe before I got her, I just knew she came from show lines. The buck I got I did get the pedigree when I got him, but I didnt look at it closely. Bad on me for not looking, but the guy was running the rabbit show, and he told me they would be a great breeding pair, so I took his word for it.

But breeding the two together I'm going to get the same rabbit as the great grand sire in three slots, and once in the grand sire category. One doe was line bred back to that buck is shown twice, which isn't a huge deal as it's line breeding, but then there also two full sisters on the pedigree. Everyone else is basically half brother and sister. The two that I have are basically aunt and nephew with several more complicated relations in the background.

I'm primarily looking for meat here, but some show might be nice too, but i'm more worried about what could go wrong with things this close than what I could potentially bring out that is good.

I know you can breed rabbits REALLY close, but is this too close? What do you all think? I'm not quite comfortable here, and how do I explain it to any potential buyers of the kits? Most people are against any line breeding, let alone lines this close. I'm a bit lost here.
ancake:

 

[Zass]

I'm going to go ahead and guess that much of the dirty work of removing the worst traits has already been done for you.
I'm sure their offspring will be very...consistent

If your looking for meat, this is also just a guess, but I'd suspect that they might produce better crossed with something else for hybrid vigor.

 

[DogCatMom]

I started out being completely against line breeding. I've learned a bit since, and now I don't see anything wrong with a single line breed here or there, or perhaps half brother and sister, but how far is too far?

I didn't see the pedigree on the champagne doe before I got her, I just knew she came from show lines. The buck I got I did get the pedigree when I got him, but I didnt look at it closely. Bad on me for not looking, but the guy was running the rabbit show, and he told me they would be a great breeding pair, so I took his word for it.

But breeding the two together I'm going to get the same rabbit as the great grand sire in three slots, and once in the grand sire category. One doe was line bred back to that buck is shown twice, which isn't a huge deal as it's line breeding, but then there also two full sisters on the pedigree. Everyone else is basically half brother and sister. The two that I have are basically aunt and nephew with several more complicated relations in the background.

I'm primarily looking for meat here, but some show might be nice too, but i'm more worried about what could go wrong with things this close than what I could potentially bring out that is good.

I know you can breed rabbits REALLY close, but is this too close? What do you all think? I'm not quite comfortable here, and how do I explain it to any potential buyers of the kits? Most people are against any line breeding, let alone lines this close. I'm a bit lost here.
ancake:

The concept you're struggling with is the Coefficient of Breeding, sometimes also called the Coefficient of Inbreeding. There's a good "work it through for yourself" explanation, with pedigrees and the math (it just involves fractions and exponents, despite the intimidating equation at the beginning of the article), here.

This is an easy-to-understand introduction to COI based on dogs; this one discusses horses; a rabbit breeder discusses line breeding and makes a software recommendation for calculating COIs here. The imprecise distinction between in- and line-breeding is discussed in this Wikipedia article.

My Bernese Mtn. Dog club featured a talk a few years ago by a genetics researcher who focused on the COI in our breed. Some associations between various traits (both good *and* bad) had been observed, and the research team was looking for dogs with one or more of the subject traits for DNA tests (cheek swabs, blood draw). I volunteered both of my dogs, but tuned out some of the talk because I had no plans to breed animals. Sorry! I hope these sources are of help anyway!

 

[Dood]

My production line of American Chinchillas is even more inbred than yours and it hasn't negatively effected them at all.

Their fertility is great, I have less than 1% stillbirths or weaning eneteritis and in 3 years I've only had one birth defect - a "pimple" that was an exposed spinal cord. I've not seen any malocclusions or other bone deformities, I've never had "snuffles" in my rabbitry and I got my first case of nestbox eye a few months ago - all in kits fatherd by my new Californian buck - so their immune systems are pretty good as well.

I too was a bit worried when I got the full brother, sister and half sister (and first cousins )and when their pedigrees arived in the mail and I saw they were even more inbred than I thought I quickly started hunting for "new blood" as I've seen first hand the sort of problems dogs and cats can have when too closely bred but I've actually had more problems with my show bloodline of AmChins.

Personally I wouldn't worry about it too much

 

[skysthelimit]

My entire rabbitry is related for more gens than are on the ped, and I "outcrossed" back into the ped and got wonderful results. Whenever I go outside the line--that's when I'm complaining on RT (well a lot has to do with food too). If the breeder removed the bad apples along the way, then the dirty work has been done for you. Right now, I'm breeding father to daughter, and the dam of the doe is half sister to the sire. I'll let you know how that goes. I did get a litter of 8 healthy kits, and she raised three more, and bred back two days ago.

One thing about pure bred, and especially dogs---in a created breed, no one is really unrelated. All GSD's can trace their ancestry back to one dog, in a straight line. And since the books are closed, except for the occasional german import, the bloodlines are closed. There are some wrecks out there, but there are good breeders that throw away junk genes, and keep lines close, and get good results (think brackett line breeding).

 

[Zass]

This might sound rough for some, but,
the difference between rabbits and dogs, especially with meat lines, is that the unwanted animals are much more...disposable.

Every dog unlucky enough to inherit the bad stuff has to go somewhere. Is someone going to adopt it? How unfair is that to the person adopting?

Unlucky rabbits are easier to euthanize humanely than almost any other animal, and they still make for an excellent and healthy BBQ, or food for dogs or cats, snakes, birds of prey...or whatever else is in need of a high protein and low fat meal. The rapid rate of reproduction also gives breeders an option to locate and remove harmful recessives from a bloodline more quickly than most other species.

If someone else has already done all that for you, consider your buns potentially much more valuable than two unrelated animals.

 

[skysthelimit]

This might sound rough for some, but,
the difference between rabbits and dogs, especially with meat lines, is that the unwanted animals are much more...disposable.

Every dog unlucky enough to inherit the bad stuff has to go somewhere. Is someone going to adopt it? How unfair is that to the person adopting?

Unlucky rabbits are easier to euthanize humanely than almost any other animal, and they still make for an excellent and healthy BBQ, or food for dogs or cats, snakes, birds of prey...or whatever else is in need of a high protein and low fat meal. The rapid rate of reproduction also gives breeders an option to locate and remove harmful recessives from a bloodline more quickly than most other species.

If someone else has already done all that for you, consider your buns potentially much more valuable than two unrelated animals.

That's how I feel about it. There is a trait that I would like to see if my dog has, but I would have to line breed much closer than is acceptable. Then, if it does occur, what would I do with the puppies? Back in the day, they used to euthanize pups that showed inherited defects, now some bleeding heart would get you for that.

Since this is not a problem with rabbits, I don't see an issue with how close the line is bred.

 

[akane]

As long as the breeder has culled properly and you continue to cull aggressively there isn't really such a thing as too much inbreeding. Some people have closed rabbitries after buying their initial stock and breed off those rabbits for nearly a human generation worth until something forces them to sell or butcher everything. I know a few lines around here that have probably been inherited/sold as breeding groups for multiple human generations with minimal or no outcrossing. If you aren't in a very busy show area of the country most of any breed is closely related. The amount of issues is determined first by how healthy the animals you are starting with our and then by how strongly they are culled for quality. I'm driving to chicago and southern IL for the rest of my nd stock because the lack of breeders around here has led to breeders being able to sell everything they produce for a high price with most of it going back in to breeding instead of being culled out.

 

[ohiogoatgirl]

x2
linebreeding is when you breed within the line and only keep the really great.. and keep getting great to really great with occasional goods.

linebreeding gone wrong is when people keep and breed animals for things that are bad and get worse. personally i think todays "bulldogs" are adorable but i mean really they are doomed from birth to have some sort of problem or other. but the short mashed face and squat build, etc, its being bred in and in and in.

inbreeding, is when you have good lines but now you hit the edge of the world and everythings going wrong.. like could be great type and fur and color etc but litters are tiny or theres abortions alot or deformed kits etc etc.

inbreeding is also, just personal view, that linebreeding gone wrong is taking all the blame masked by the word inbreeding when its not so by people who dont know or dont care enough to find out.



one good example would be fainting goats (tennesse goats, tennesse fainting goats,...) which all came from one guy in tennessee with 1 buck and 5 does who goat these funky kids that would faint. now i dont even know what the population of them in the USA would even be but i know theres plenty. and actually the only thing wrong with them is the myotonia gene that causes the fainting to varying degrees.

 

[PSFAngoras]

It's good to hear so many reassuring views. Some of the bigger rabbitries around here seem to frown on line breeding, so it's no wonder that so many of is who are starting to get into this with a breeding goal feel like line breeding is something that should be avoided.

 

[akane]

With good linebreeding you should never hit the end. Entire species have gone on for 100 or more years off a handful of animals. Most of our pet rodents from gerbils to more exotic things like degus (started with 10 individuals), the jird species, and chinchillas or the marsupial sugar gliders(imported to indonesia and then some offspring of those imported to the US) started with a few pairs often imported for scientific study and then importation being closed. Chinchillas had a slightly bigger start with a few buying larger numbers to start the pelt industry but still they were listed endangered at the time and none have been allowed to be taken from the wild since. Break it down further in to breeding for new colors and coat mutations and if there was a limit to inbreeding even when done well we would have seen it in most exotics species. Sometimes a disorder pops up but in another 20 years it is usually mostly removed. Right now with sugar gliders they are working on the male mosiacs sometimes being infertile and trying to cull them all out of the species in favor of lines that don't throw sterile offspring. With chins a few of the color varieties have gotten a bit smaller or weak in coat density but they've already fixed that on a couple colors and greatly improved one of the newer colors in the past few years. There is a chinchilla coat mutation that 2 breeders have been working on for I believe about the past 50years without new stock until they recently offered them for sale to the public and set aside a few to export to Europe. Each person will have to cross to their own line of standards and then inbreed for probably close to as long before they make another line with the same quality. Some will probably buy as many of the original breeding (including regular coated animals) as they can so they do not have to outcross and lose quality only to spend a lifetime breeding it back in.

 

[ohiogoatgirl]

ya i mean look at nature even. once natgeo show i saw once talked about how there was a storm on the mainland and these marsupial or something animals little cute things were holding to dear life on this big tree (they lived in trees) and it got tossed in the ocean.. floats and floats and somehow a bunch of them hibernate or whatever and wake up and the fallen tree landed on an island.. well fast forward and theres this species of cute little marsupial things on a couple islands hundreds of miles from the mainland.
all from some that hung tight to a fallen tree in the ocean. yup.

(((goes hiding from my own sheer nerd outbreak i just had xD )))

 

[squidpop]

I think that's also what happened with every species in New Zealand. A pair of birds some how flew here and bred or a pair of reptiles clung on to something and floated here. The theory as to why there are no mammals in New Zealand is that, if they did cling on to a branch they would have frozen because NZ is so far from other land masses, while cold blooded reptiles could have survived in the cold ocean for longer periods of time.

 

[Prisma]

Nothing wrong, ideally should be best route if bads are weeded out and not fixed into a herd. Egyptians wed relatives only for a very long time, probably some other groups too, and had fewer issues to a point but there were also problems that popped up from hidden recessives (cleft palates for one). Eat the bad keep the good with rabbits.

 

[Bad Habit]

I had a line that started with a pair that were 1/2 brother and sister, and I kept back a doe to breed back to the sire. Didn't have any birth defects, kits are hardy and easy going and healthy... but I started getting odd markings. Probably just something doubling up in my particular line, and I'm breeding for BEW so colour doesn't matter so much to me. But there you have it