Line Breeding

[poetrue]

Hey Everyone,

I've heard a lot of back and forth on line breeding whether you should or shouldn't do it. Which is why I'm putting this question in the debate section. My questions are more for informational purposes to myself and other breeders that don't know much about it.

What is your purpose in line-breeding? If you do line breed, how closely related are the chins you are breeding together? Do you find certain chin relations work better line bred versus others - like breeding cousins versus half siblings etc.?

Cheryl

 

[mark miller]

There are many different ways to use line breeding effectively. If you really get into the most successful award winning breeders lines. You will find that they all use a form of line breeding. I don't know of any special type of line breeding that is most effective for everyone, as far as a brother to sister, or father to daughter, or half brother to half sister, or grand daughter to grand father, sometimes it might work but not as a general rule for everyone. From my experience it's about understanding the traits and qualities that each line carries and then line breeding those traits to set them in deeper to the offspring. For example, I like to select a female with my good blue color line and breed it to a male out of my size line, then I take the offspring back to the blue color line, and then take that offspring back to the big size line again, and back and forth on and on. You really need atleast 2 established non-related lines to effectively line breed with and the more you know and understand about their lineage the better. Line breeding with only 1 line will become too closely related quickly and can lead to higher instances of genetic defects and sterile offspring. Line breeding is really only for experienced quality breeders, it's not something you should be doing when just starting out in breeding chins. The problems that you most often run into with line breeding is bringing out traits that are unexpected or not seen in the parents. Some times certain traits will skip a generation and then reappear in a line breeding. You have to remember line breeding will set in common traits, both good and bad traits. That is where strong evaluation needs to be done on offspring from line breeding. For example, if there is 1 bad trait like a grey belly gene in the lineage of an animal and you line breed that animal repeatedly, before you even realize it you've set that grey belly gene into that entire line and most of what you've crossed it with. This is an example of what most commonly happens when someone starts line breeding animals that they don't know the background lineage on and don't know how to evaluate the qualities and defects in their offspring from the line breeding. When done effectively by the experienced rancher of chinchillas, line breeding can be a tremendous tool to further set in good desired traits in their animals. When done by inexperienced new breeders line breeding can lead to setting in all kinds of health defects like teeth problems, fur defects like chewing, or swirly patterned lay down fur, grey bellies, grey bars, etc. Because of this serious line breeding should really only be done by experienced breeders that know and understand the lines they're working with and the backgrounds of those lines or the effects of line breeding will be more negative for your chins then positive.

 

[mishalaa]

Line breeding does not "lock in" or "set in" traits. What it does is increase homozygousness in the genome, one effect of which makes offspring more uniform in appearance. This is great when you want 100 identical looking chins to make a coat, for being more consistent on the show table, and for knowing with more certainty what genes will be passed to any offspring.

Another effect of increasing homozygousness is it brings out recessives - such as malo, furchewing, blueness, clarity.

There are only two alleles per gene, so a certain genetic allele cannot be "set in deeper," either - it's either homo, hetero, or not present. It cannot get "deeper" than that. Expression of any trait you target in linebreeding can be lost with one outcross.

Linebreeding can be very beneficial, but you have to cull and cull hard when undesired traits appear.

The most common linebreeding is father to daughter - for practical reasons (the male can service more than just one female) and for relatedness - because of mitochondrial DNA, which is only passed from the female, everyone is more related to their mother than their father, so a father/daughter pair is less related to each other than a mother/son pair. Subsequent generations are a little more open as to which relatives should be used, depending on a LOT of factors.

Typically as the inbreeding coefficient increases (i.e. the offspring are more "inbred"), production goes down. This is when outcrosses are necessary in order to keep producing, but you have to be as selective about your outcrosses as you are with the chins you originally chose to linebreed.

 

[poetrue]

Mark.

Thank you very much for replying it was extremely helpful. I've never once tried line breeding but have heard many arguments both for and against it. I think I begin to understand where a lot of the negative comments come from. Line breeding isn't something I would start without a lot of thought and experience, but I'm sure there are those that jumped into it prematurely and ended up with negative results.

Mish,

Your post was just as helpful. I had assumed that Mark basically meant what you stated about the homozygousness, if not worded the same. I also think it's good to think about the higher culling factor that would come with linebreeding. Obviously if a negative trait does become homozygous in the line you have to cull way up in order to stop that trait from progressive through the rest of that line going forward.

I never realized about the mitochondrial DNA, that's very useful to know. It would definitely be a factor in determining some of the line bred pairings.

Cheryl

 

[mishalaa]

When researching linebreeding, I've come across the terms "locked/set in," and "set deeper" in more than one place - put in such a way this gives the impression that a line that has been linebred for blueness (just for example) for four generations, would take four generations of outcrossing to undo. This isn't true, it can disappear in one if you don't choose your outcross well.

I should also mention that while linebreeding can and has brought out malo and other health maladies - it has to be in the lines for that to happen. If culling like crazy you can actually breed these genes out (rather than "set them in") faster by linebreeding than by constantly outcrossing.

There is a very good section on linebreeding, including diagrams that show several generations of linebreeding, in Chinchilla Care by J. Houston.

 

[mark miller]

I have studied V.P. Wyatt, Chapin Hand, and Ralph Shoots breeding practices. All of them were very successful breeders of chins that used line breeding extensively. V.P. Wyatt had the smallest herd and it was all related from line breeding. He had clear blue color throughout his standards as a result from his line breeding. I studied his herd book extensively as well as Chapin Hand's. This is where I learned my line breeding practices. I've studied Genetics through school and College to apply to my chinchillas. I know what the book says, but sometimes you find differences when you apply that to real life experience. I developed a blue color line of females that continued to be bluer and clearer in color every time I bred them back to the original color line. By the time I had done this for several generations I had a line of females (about 20 of them) that it didn't matter what male from what lines I put them with all their offspring carried the blue color. Granted, I only used top quality show males from different backgrounds with these females, but the results were the same. All of the female babies from these breedings were always bluer then the males. I'm truly convinced that I line bred that blue color gene into those females so much that it became dominant in their offspring regardless of the male I put them with. This isn't a theory of mine, this was proven in a live study in our barn with our breeding program. I've based all my breeding practices on line breeding with chinchillas. It's how I was taught to breed my chins and I've taken it to the next level above the way Pick (V.P) and my Grandpa Chapin taught me. I actually think about 2 generations ahead on my line breeding always trying to evolve it to the next level. When I pair 2 animals to line breed, I already know who that offspring will be mated to when old enough and usually the next generations offspring as well. This is how I continue to improve my quality each year. I've been doing this for 30 years, it truly is my passion. I agree with you Mish that sometimes 1 wrong outcross can completely change the qualities in the offspring which I have experienced also. But, I truly did develop a heavily line bred group of females that carried that color to their offspring when mated to several different line males and I have the real life results to prove it. I continue to work with that line of females and am now in the process of crossing them with a completely new line I've never tried with them before. I know exactly where I want to go with it and it's going to take me 2 more generations of line breeding to completely mesh the lines the way I want to. I'm anxious to document my results of this current line breeding experiment.

 

[poetrue]

There is a very good section on linebreeding, including diagrams that show several generations of linebreeding, in Chinchilla Care by J. Houston.

Mish thanks I have not heard of this book before. I will definitely have to check it out and see what it says! I'm sure it will be helpful on breeding quality chins and caring for chins overall.

I have studied V.P. Wyatt, Chapin Hand, and Ralph Shoots breeding practices. All of them were very successful breeders of chins that used line breeding extensively. I studied V.P. Wyatt's his herd book extensively as well as Chapin Hand's. This is where I learned my line breeding practices. I'm anxious to document my results of this current line breeding experiment.

Mark for those of us out there that do not have access to the long-term ranchers or even to any bigger breeders in our area, do you have any good book suggestions on chinchillas in general as well as anything specific to line breeding?

Additionally do either of you have any suggestions on contacting any of the ranchers in order to develop a mentoring type relationship for any of the younger breeders that are really looking to learn and improve chinchillas? I know I've always used the shows to really start talking with the bigger breeders/ranchers all over the country as well as always helping out with classification or animal handling to be able to get a good look at all the animals in the show and develop that eye for quality.

Cheryl

 

[mishalaa]

Mark - I'm truly glad you've developed a really blue line. That's a great example of what linebreeding for several generations can do. However, I'm not convinced you've made the trait dominant and set so deep that you can breed them to anything. You said yourself, you only used top show quality males as your outcrosses, and I'm certain you're no slouch when it comes to picking from lines to breed, so there's not much of a control in this experiment. That said, I don't want you to prove me wrong either - I'd rather you keep doing what you're doing and breeding blue girls. =)

I have not yet gotten far linebreeding my herd, but I do have several generations mapped out as well with what I want to achieve. However, as I'm just starting out I am prepared for a lot of nasty to pop up, so I am leaving that map pretty loose for contingencies.

Cheryl - If you're coming to Nationals again this year, Jay Firebaugh would be a great person to talk to. He only has about 16 breeding females, has linebred extensively, and actually beat everyone including Hummel with less than a full string for the standard breeder award at Nats last year, so he's been pretty successful at it.

 

[ticklechin]

Should line bred chinchillas be sold as pets? My worst case of genetic issues in one chin and exibited the issues at 11 months old was produced by a experienced rancher who line bred. Was it my bad luck or do the genetic issues come up?

 

[poetrue]

Cheryl - If you're coming to Nationals again this year, Jay Firebaugh would be a great person to talk to. He only has about 16 breeding females, has linebred extensively, and actually beat everyone including Hummel with less than a full string for the standard breeder award at Nats last year, so he's been pretty successful at it.

Thanks for the tip. I had seen him briefly at nationals last year and saw how well his animals did too. So this year I'll have to see if I can get a chance to talk to him. I'd love to pick your brain too on what you've tried so far and what has/has not worked for you. I've been working with the same line for many years now always using outcrosses and have had much success with them. I've been contemplating line breeding, but really want to learn more before dipping my toes in!

 

[Vyxxin]

Like said by Mish and the others, linebreeding does NOT create health issues so much as cause them to be expressed quicker. Were you unlucky? Not really, there are (I'm sure) many animals with exacerbated health conditions due to linebreeding...should that animal have been sold as a pet? Well, idealistic answer is no...due to the properties of linebreeding ranchers/breeders should be very careful about selling linebred animals from questionable health lines. Does it happen? I'm sure. You said your animal did not show signs until it was 11mos old...so basically 9mos after it was sold. You do need to be very careful when linebreeding because while it makes good traits stand out better it can also make bad traits stand out better. Most good breeders (Mish, Mark...) will tell you this is the best way to cull out bad qualities because you aren't passing it unknown to offspring by outcrossing. You're causing it to show up with linebreeding. BUT, this goes back to the loose use of the word cull I suppose...

 

[poetrue]

Should line bred chinchillas be sold as pets? My worst case of genetic issues in one chin and exibited the issues at 11 months old was produced by a experienced rancher who line bred. Was it my bad luck or do the genetic issues come up?

Dawn I don't think that genetic issues is specific to line breeding. The worst case of malo I ever had in my herd came from 2 completely unrelated parents from 2 different breeders. The parents have never showed any signs of malo and had been bred multiple times in the past with other chins and none of their other kits have shown any signs of malo. Together though they had 2 kits in a row (breedback) that needed teeth clippings prior to being weaned. Neither parent is being bred at this point, they were retired after this breeding. Both kits though needed to be put down prior to being 1yr old. Genetic malo is a recessive trait so it can seemingly randomly pop up in anyones herd regardless of their breeding style. When linebreeding it is more probable to get kits homozygous for malo though if any chin in the line carriers the malo gene, since you'd be mating a malo carrier back to another malo carrier. Which is why a breeder needs to cull and cull hard per what Mish stated, if any chin in the line pops up with a genetic fault like malo.

Cheryl

 

[VolunteerChin22]

In theory, in the old days of chin linebreeding there was no pet market so that scenario would be non-existant/small. What would happen is the animal in question would just be pelted/euthanized and the line culled. Problems in the pet market are a modern day issue.

It does however probably create a situation for the breeder to be notified faster if there is a problem - say take Dawn's 11 mo chin for instance - if that chin had been pelted in prime at 9mo then the malo would have been unknown to the breeder and they would have continued to linebreed creating more problems. Of course this would rely on the pet person actually knowing where the chin came from and notifying the breeder - possibly few and far between.

 

[ticklechin]

So for the flip side of the coin, could a herd that has been line bred with no outcrossing and those with issues culled eventually be malo or genetic issue free? If that could happen, sign me up. As far as my chin goes, he was a cull from the ranch I got from a middle man, so I have no idea if the ranch knew what happened. I told the middle man.

 

[Vyxxin]

Well, to a large degree the answer is yes. If strict culling took place and it was a closed herd...but I think MOST agree that an outcross is needed EVENTUALLY. Still, hypothetically yes. If you buy an animal from a linebred herd that strictly culls...your animals should be much more disease free than those that are outcrossed.

The other side of that coin, if everyone supported pelting/culling to the truest sense...most herds would already be much more genetically sound. Granted, there will be shady breeders in every industry but pelting/culling has become such a dirty word that being known to take part in such practices can black list you as a breeder.

Sidenote, regardless of outcrossing linebreeding a LOT of malo gets passed along because in a pelting herd the animal may not reach the noticeable stages before getting pelted.

 

[poetrue]

Sidenote, regardless of outcrossing linebreeding a LOT of malo gets passed along because in a pelting herd the animal may not reach the noticeable stages before getting pelted.

Ange,

Wouldn't enough of the chins be kept for breeding purposes to catch the malo in the lines though, even if the rest are pelted at their prime prior to malo setting in?

Cheryl

 

[Vyxxin]

Well yes, and no. Because malo is recessive only some of the kits would have malo even if both parents carried the genes. THEN out of ALL kits born only the very best would be held back for breeding and the rest would be pelted. SO, it could be many years before a kit is kept for breeding that got both recessives proving the parents to be carriers. Regardless, and this could be happenstance, any malo I've personally ran into came from tight (not entirely closed) herds that were primarily pelting herds. Not to badmouth ranchers, or pelting, as those herds DO tend to be very much more aware of malo and keeping their herds free of it...but the fact remains that if you pelt a lot of your offspring malo could go undetected if you're not very careful about your breeding practices.

 

[ticklechin]

Vyxxin, I appreciate your honesty about malo and why we still have it when theoretically it could have been bred out of chins, its what I thought for years but never heard said out loud by someone in the business.

 

[mark miller]

Cheryl, it sounds like you're doing it right. You've got a line you're familiar with, have worked with, know the qualities of the animals in the lineage. That's a huge advantage when line breeding. You know and understand the line your working with and what's behind it. The female line that I developed and line bred was purely my Grandfathers lines when I started with it. I knew the animals behind it, remembered their strengths and weaknesses and knew exactly what I was trying to establish with the line breeding. It was kind of a fluke in my case. I had a female pop out of an average pair of parents that was crystal blue color on top with a sparkling white belly. I researched further back into her lineage to animals I had to ask my Grandpa about because they were before I got into chins. He helped me pinpoint exactly where the blue color came from in the lines. The female was a 1st place at Natl's. She was a longer body type animal, lacking in fur density,conformation, and overall size. She was the bluest female I had ever produced and I knew right then I had the tool I needed to start a line breed with. I knew her strengths and I knew her weaknesses and I knew her background. These are the essentials when getting into line breeding. My purpose for the line breed was to re-produce the blue color and white belly with more frequency while trying to find the right outcross male to improve fur density, size, and conformation. From my experience, in order to successfully line breed you have to really understand the qualities of the animals you're line breeding. That's not just in the animals your breeding together, but their parents and grandparents and as far back as you can go. When you physically know those animals and their attributes you can isolate where the traits are coming from in the offspring specifically to what ancestor. This will assist you in taking the line breed forward and knowing what line to go back to in order to bring out the next desired trait that is still lacking in this offspring produced. Knowledge of the animal, research of the lineage, understanding of the qualities both that you can see and what you desire, strict evaluation of the offspring, and knowing what the goal you're trying to attain is what will give you the best results when line breeding. Once you've established all of those things, then it's just trial and error with the animals till you attain your line breeding goals.

 

[mishalaa]

Yes - in theory - if unhealthy animals are culled, a strain could be developed that is genetically disease free. I work at an animal research facility at a major university where we have strains of mice that have been linebred with no outcrossing for over 300 generations. More is known about their DNA than is known about the human genome.

I say in theory because we still get the occasional mouse with malo - but when it's one in thousands of genetically identical animals, the cause is most likely environmental rather than genetic.