|
Post by Deleted on Jan 23, 2012 4:47:23 GMT -5
I'm just curious as to the effect of inbreeding in ferrets are? I know amongst various other species, inbreeding to some extent can be beneficial & in others it can be quite a lethal practice. I've read quite a lot on the topic in other species as such, but haven't been able to find anything that is particularly informational.
|
|
|
Post by allie516 on Jan 23, 2012 7:17:45 GMT -5
In breeding for any animal/ species is not good at all! I know in ferrets. It can lead to blindness and deafness. (If I am wrong someone feel free to correct me)
In Chinchillas It can lead to molo,(a teeth disease where the roots of the teeth grows into the skull) It can lead to lack of limps, or to many limbs. It can lead to blindness and deafness. Frankly any responsible breeder Will Not In breed!
I am sorry If I seem kinda rude. I have seen people inbreed different animals. And really bad things happened. I have seen animals born with a under developed spine, they let the poor thing starve to death, I have seen chinchillas born with no eyes, cats with extra parts. It is not pretty.
Just wanted to add. I do no breed. I never will, I have seen people try to breed, and it is heart breaking!
|
|
|
Post by Deleted on Jan 23, 2012 10:25:11 GMT -5
Ferret breeders do inbreed and linebreed. It can be good or bad. Depending on the lineage. (Study their lineage and you will pickup on it.) Here is a good web site that explains inbreeding and linebreeding. bowlingsite.mcf.com/genetics/inbreeding.html
|
|
|
Post by joan on Jan 23, 2012 12:13:25 GMT -5
I posted this on the Ferret Genetics group some years ago when there was a discussion of linebreeding and inbreeding: I was sent the following years ago by a long time Basenji breeder friend for those who don't understand why continual outcrossing is a path to disaster: "From spending some time on a genetics list (where there were some very good people and a lot of 'think they knew it alls') I noticed that the main problem was that people were trying to apply "population genetics" to individual breeding programs and could not separate the two in their minds. Population genetics preaches diversity (anti-inbreeding). And yes, diversity is necessary in the whole population. But short of God, who controls whole populations?? The owner of the list, a professor of genetics at a Canadian collage, ran a simulated breeding program with 8 breeders founding a theoretical breed. I took part in the program. Each breeder had a dog and a b**ch (littermates) to start. There were two inherited defects in the breed – one early onset and one late onset. Little was known of the background of the dogs because they were imported. A few of the foundation dogs were known to be related. Some dogs carried one problem and some the other but none of these foundation dogs carried both. Some didn't carry either. This was all the information we were given to start. Everyone bred theoretical litters. Since this was basically a diversity list, six of the breeders immediately went after diversity by breeding to males as distant from their bitches as they could get. One other breeder and myself believed in line- and inbreeding. The other breeder's dogs had known relatives in the program so she bred to them. Not wanting to cause a furor on the list, my first litter was an "accidental" breeding of brother to sister - when it turned out I had a fence climber. <G> This other breeder's dogs had the early onset problem. Since she had linebred she quickly discovered this and figured out where it came from so she knew which dogs to avoid in future breeding. In a few generations she had clear stock. My dogs carried the late onset problem and fortunately it showed up in my first litter so I knew it was there before I had gone too far down the wrong road. With late onset problems you can be in deep, deep do-do before you realize it. Both problems proved to be recessively inherited. I then bred my dogs, that hadn't come down with the problem, with dogs from the other breeder's line. As her dogs were now free of any problems the only thing we had to worry about was carriers of my late onset problem. By further linebreeding this too could be eliminated. The study was based on 10 generations and in that time the other breeder and I knew exactly what we had and where our one problem may be hiding. Given another few generations we could have eliminated it entirely. Seeing the results other people got from using our dogs helped too. The health problems were randomly computer generated within their possibilities. The other six people thought they could control problems with outcrossing. Some of them started with the early onset problem, some had the late onset problem and at least one of them had clear dogs with no problems. Each of these six breeders bred to six or seven other people's dogs. Everyone kept records that were shared. After 3 or 4 generations, these 6 people started seeing the problems. After a few more generations they could no longer outcross because everyone else had done the same thing and bred to all the different dogs. All their pedigrees were the same hodge-podge of the many foundation dogs and now they all carried both problems. Since none of the six had linebred it was never discovered which of the foundation dogs were the healthy ones. These were the dogs that should have been used for back-crosses. Now it was too late. The six people with the outcrossed dogs now had affected and/or carriers of two genetic problems and they had no idea who carried what recessively. Instead of there being some clear and some with one problem all of their dogs now carried two problems recessively. Now that the six people had already incorporated everything into their breeding programs there was no diversity left. The two breeders who line bred had healthy stock with only a few carrying one problem and they knew where to expect that problem to show up. So, who's ahead here? The only way to keep diversity within a breed is by line breeding. Let me say that again so you know I didn't make a mistake. "THE ONLY WAY TO KEEP DIVERSITY WITHIN A BREED IS BY LINE BREEDING." One breeder must linebreed on a certain few dog long enough to establish a separate line (different from all the rest). Another breeder must linebreed on a few different dogs and establish another line. A third breeder should linebreed on yet some other dogs and establish yet another line. A fourth breeder – etc., etc., etc. NOW we have diversity! Even if all are descended from the same limited number of ancestors, by having different lines, we maintained diversity. When you linebreed and run into a problem you can always outcross. If you are already outcrossing and run into a problem (and you will) where do you go then? My grandmother always used to say, "Sweep your own doorstep first." If each breeder creates and monitors their own line, the breed will prosper. No breeder can maintain diversity by himself and any attempt to do so will lead to disaster for the breeder and the breed – it takes a network of breeders working together with individual lines to maintain diversity. Linebreeding and inbreeding get a bad rap because `popular studs' are overused. The big winners owned by the politically correct individuals are bred to the most. Soon they are in everyone's pedigrees multiple times. Their problems are spread throughout the breed and the diversity of animals that are not big winners or properly owned is lost."
|
|
|
Post by Deleted on Jan 23, 2012 16:17:30 GMT -5
This is so true....especially the following..... "Linebreeding and inbreeding get a bad rap because `popular studs' are overused. The big winners owned by the politically correct individuals are bred to the most. Soon they are in everyone's pedigrees multiple times. Their problems are spread throughout the breed and the diversity of animals that are not big winners or properly owned is lost." Also, the desire to fix traits within a line can result in disaster....it takes a LOT of time and effort to develop a demonstrated-to-be-healthy line with desirable characteristics. Some breeders have become "successful" even though they have bred for high-turnover to fix a trait more quickly.....animals that are bred too often/too soon result in lines that can have big issues even though they look great and win at shows.....it takes time and patience (generations) to prove/demonstrate the integrity of a genetic line. Again, I could NEVER be a breeder....it would make me nuts because I'm too much of a control freak. The "ups and downs" of breeding would result in my death due to STRESS! -jennifer
|
|
|
Post by Deleted on Jan 23, 2012 16:31:24 GMT -5
Honestly I couldn't follow a lot of that about line breeding etc but I never would have thought that inbreeding/line breeding to any extent could be a positive thing. Learn new things every day! And I'm with you Jennifer -- I could never be a breeder!
|
|
|
Post by Heather on Jan 23, 2012 16:33:00 GMT -5
Thank you Joan. Very nice. Breeding always sounds easy from the wrong side of the fence or for those that are watching. Breeding is a study in not only biology and genetics but of probability and cause. Most of the people who've been instructors/mentors/friends line breed with the occasional outcross. Joan is correct in her process, she knows not only from the simulation that she partook but also from the her lifetime study breeding dogs and ferrets. One of the problems is when a problem is discovered (and everybody can point to the farms if they like) they won't retire that line if the issue is too severe. As a breeder one sometimes has to count up ones losses and admit that a line is too damaged to repair and walk away and start over. ciao
|
|
|
Post by katt on Jan 23, 2012 17:52:42 GMT -5
The problem with inbreeding (and any type of breeding really) lies in irresponsible breeders, and recessive mutations. *cough cough FERRET MILLS* *ahem* If there is a recessive mutation an animal can carry the gene without showing symptoms so to speak. With Proper Line breeding, this can be effectively eliminated as Joan stated. However, if not done by someone who knows what they are doing, inbreeding can result in proliferation of the recessive mutation(s) and a decrease in the health of the animal. Then you end up with the same problems if not more, as outcrossing as Joan described it. With ferret mills, they are typically breeding for "fancy" exotic colors that will sell faster and for more $, as well as more docile temperaments, with little regard to the overall health of the animal. Thus, you end up with a higher potential for homozygous recessive animals who express (or "show symptoms of") the recessive mutation/defect. Now that can happen with or without inbreeding, it is just with inbreeding you have relatives who are all more likely to carry the heritable recessive gene as opposed to the more random chances with a non-relative (though without knowing genetic background, you could be adding in a whole new slew of defects), and thus a higher chance of getting a homozygous recessive animal IF YOU ARE BREEDING IRRESPONSIBLY. Unfortunately, irresponsible breeding is irresponsible breeding whether you are outcrossing or line breeding. IMO the breeders Joan mentioned who outcrossed were breeding irrespinsibly as they were not 100% certain of their line's genetic background, and continued to breed to uncertain genetics, creaiting further and further uncertainty. Whereas by line-breeding the other 2 were able to decipher exactly what the genetic backround was. The key with any breeding is careful research and preparation, knowledge of the genetics of the animal you intend to work with, and a knowledge of the genetic background of the individuals you are chosing to breed. If you don't know their background, well then you'd better know how to line breed to figure it out and weed out genetic defects. I hope I'm making sense and not rambling too much here. ;D In summary, YES inbreeding can be very bad when done incorrectly/irresponsibly, but ANY and ALL irresponsible breeding can have very bad results.
|
|
|
Post by Heather on Jan 23, 2012 20:54:48 GMT -5
Exactly You made perfect sense...hence the whole idea of the farms. They're line breeding with a specific purpose regardless of health issues. They have a very narrow and specific agenda (colour, gentleness and profitability), unfortunately, health and longevity are not in the agenda ciao
|
|
|
Post by Deleted on Jan 23, 2012 22:16:34 GMT -5
It can be VERY difficult to determine whether or not a defective gene is present because you cannot test for it (at least not with ferrets). Problems with DNA can be inherited (germline) or acquired (somatic), so it's VERY DIFFICULT to assess breeder ferrets for genetic issues before breeding takes place. This is why it takes generations to determine the quality of a genetic line. Somatic mutations can and will cause issues - the only way (other than genetic testing, which is not available for ferrets) to distinguish between germline ans somatic mutations is by tracking the offspring and identifying patterns of inheritance.
This is a LOT of work, and TIME is required to gain a true understanding of the quality of a genetic line. Unfortunately, MOST breeders in the US have intermingled lines, and even the privately bred ferrets succumb to genetic issues. Also, the US show systems do define color standards. Another thing I fail to understand is show classes for ferrets that are physically challenged, which can include ferrets born with issues most likely caused by germline mutations. There are NO guarantees with any ferrets. Even the best lines are NOT perfect.
Good breeding is very difficult!
-jennifer
|
|
|
Post by lumene on Jan 23, 2012 23:15:16 GMT -5
If only humans were that smart with each other instead of breeding like rodents...
|
|
|
Post by joan on Jan 23, 2012 23:20:01 GMT -5
Thanks, Heather, but I can't take the credit for what I posted. I got it from a long time breeder friend who had found it on a breeders forum. She sent it to me when I was looking for a way to explain line/inbreeding to people who didn't understand how genetics work or how/why to plan a long term breeding program.
While I don't doubt that MF (and the other commercial breeders) did a fair amount of inbreeding to set and produce the fancy colors when they first appeared, I'm sure they went back to routinely outcrossing once they had enough breeding stock with the desired colors and temperaments...bear in mind, MF has many THOUSANDS of ferrets, and have brought in thousands of unrelated breeding stock at least twice in the past 15 or so years that I'm aware of. AFAIK, they still maintain sable breeding stock with full pignentation for their laboratory sales as research facilities wouldn't want the problems inherent in the silvers and dilute colors. It's highly unlikely that the two are interbred, as it's been years since I've seen pics of any MF ferrets with full pigmentation.
What the continual outcrossing, along with breeding for the fancy colors, has accomplished in both the commercially and privately bred ferrets is to produce breeding stock which carries most or all of the genetic defects and diseases in ferrets. I watched the same thing happen in my breed (Basenjis) during the late 70s and 80s, as the new breeders coming in put winning and breeding to the winners ahead of breeding for health and temperament.
When I began showing/breeding Basenjis in 1963, they were an extremely healthy, long lived breed from an intensely inbred and linebred background where the problems in the original breeding stock from Africa had been brought out in the open and eliminated. There were a number of breeders in the UK and the US with top quality lines which were all closely linebred and inbred...most of these lines were healthy and long lived.
During the 70s, Basenjis began to do very well at the group and BIS level, which brought in newcomers who were only interested in winning and had very little interest in learning about the background of the various lines...or in the long term health of the ones they bred. Thus, serious diseases with late onset which were carried by the top winners in that period were spread throughout the breeding population and it became harder and harder to find quality dogs to breed to which had healthy backgrounds.
My own line was based on two old UK lines which were established in the 50s and I outcrossed only when I needed to correct a fault or bring in a trait my line lacked. As the other breeders with these lines called it quits, I gradually ran out of dogs with the quality, type, health and temperament I wanted. I was not willing to compromise my standards to bring in dogs with a background of health problems and/or genetic defects, so I called it quits in 1992...placed my younger ones with other breeders and kept my older ones.
I didn't miss the showing, as there were so few breeders left who were interested in anything but breeding/showing winners, but I did miss planning the litters and raising the pups. I'd been interested in ferrets since I first saw them in the early 80s, so decided to try that after rehabbing pet shop ferrets for a couple years in the mid 90s. After a few years of breeding and researching US ferrets (and ferret breeders), I wrote one of my long time dog breeder friends that it seemed quite clear that I'd gone from the frying pan into the fire as I would have to import breeding stock if I wanted to continue breeding healthy, long lived ferrets...which is what I've done.
While it's highly unlikely that the US breeders who have been breeding the fancy colors for 10-20 years or more will ever acknowledge that their winning lines should be removed from further breeding due to all their health problems, I am encouraged that I've heard from others in the past few years who have realized that the vast majority of US bred ferrets are genetic disasters and are interested in breeding sable ferrets free of the fancy colors backgrounds.
|
|
|
Post by Deleted on Jan 24, 2012 11:23:32 GMT -5
Just chiming in with the only info I know to add to this discussion:
Cichlids (Fish) specifically Lake Malawi African types are genetically wired to prefer siblings for mating purposes in the wild. Sort of a "I know I'm healthy and dominant so my siblings are too" mentality. Many breeders using F0 or F1 stock have no success breeding in captivity until the pairs are made of siblings.
~Kelli
|
|
|
Post by Deleted on Jan 29, 2012 23:37:54 GMT -5
Inbreeding is a major reason why ferrets are a indangerd spises on my planet, not cool.
|
|
|
Post by Heather on Jan 30, 2012 1:18:44 GMT -5
Not exactly Aaron....people who don't know how to use it correctly is why ferrets are an endangered species ciao
|
|