Wright´s Coefficient Of Inbreeding

[netheredge]

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The whippet archives as from early July,2011 contain 10 genereation pedigrees together with percentages relating to the coefficient of inbreeding. Could some member of this forum supply reasonable guidlines as to acceptable C.O.I. percentages. Would it be correct to say that a dog with a C.O.I of say 25% mated to a bitch with a C.O.I of 25% would produce offspring with a C.O.I. of 0.00% providing there is no dog commom to both pedireees.? If both parents have a C.O.I. of 0.00% and there is no dog common to both pedigrees would it also be correct to assume that that the offspring would have a 00.00% C.O.I? Has the Kennel Club laid down any rules under which a litter with a C.O.I exceeding a certain percentage would be refused K.C. registration?. Mathematics has never been my strong point although I did manage a pass at "0" level and later qualified as a certified corporate accountant. Looking forward to your comments. Netheredge

 

[Tiger Lily]

I don't know the ins and outs of the calculations myself but here is a quote from Wikipedia.....

Wikipedia link on Inbreeding

The inbreeding is computed as a percentage of chances for two alleles to be identical by descent. This percentage is called "inbreeding coefficient". There are several methods to compute this percentage, the two main ways are the path method[9] and the tabular method.[10][unreliable source?]

Typical inbreeding percentages are as follows, assuming no previous inbreeding between any parents:[dubious – discuss]

Father/daughter, mother/son or brother/sister → 25%

Grandfather/granddaughter or grandmother/grandson → 12.5%

Half-brother/half-sister → 12.5%

Uncle/niece or aunt/nephew → 12.5%

Great-grandfather/great-granddaughter or great-grandmother/great-grandson → 6.25%

Half-uncle/niece or half-aunt/nephew → 6.25%

First cousins → 6.25%

First cousins once removed or half-first cousins → 3.125%

Second cousins or first cousins twice removed → 1.5625%

Second cousins once removed or half-second cousins → 0.78125%

An inbreeding calculation may be used to determine the general genetic distance among relatives by multiplying by two, because any progeny would have a 1 in 2 risk of actually inheriting the identical alleles from both parents.

For instance, the parent/child or sibling/sibling relationships have 50% identical genetics.

I hope this helps!!

 

[Avalonia]

The whippet archives as from early July,2011 contain 10 genereation pedigrees together with percentages relating to the coefficient of inbreeding. Could some member of this forum supply reasonable guidlines as to acceptable C.O.I. percentages. Would it be correct to say that a dog with a C.O.I of say 25% mated to a bitch with a C.O.I of 25% would produce offspring with a C.O.I. of 0.00% providing there is no dog commom to both pedireees.? If both parents have a C.O.I. of 0.00% and there is no dog common to both pedigrees would it also be correct to assume that that the offspring would have a 00.00% C.O.I? Has the Kennel Club laid down any rules under which a litter with a C.O.I exceeding a certain percentage would be refused K.C. registration?. Mathematics has never been my strong point although I did manage a pass at "0" level and later qualified as a certified corporate accountant. Looking forward to your comments. Netheredge

Greetings, I am one of the team members of TWA and think I can answer your questions.

In answer to your first question, would it be correct to say that a dog with a high coi bred to a bitch with a high coi would produce offspring with a lower coi providing there are no common dogs in the pedigreee, the answer is yes, especially if there are no common dogs in the first four or five generations. After that it becomes more difficult, if the dogs are from the same country and same basic gene pool not to have at least some common ancestors. For the record, we own an English Ch. whippet with a coi over 25 because she is tightly linebred for multiple generations. I chose her and testmated her to the English whippet male from another kennel who has, to my knowledge, the highest coi of any English whippet I have seen... higher than our bitch -- in fact for 7 generations it is at or over 30. The coi of the children dropped to 15, which may still be high for some people but it not unacceptable compared to being over thirty.

In actual reality when we bred our bitch to a male that we imported from Finland who carries our earlier breeding from the late 80s (containing some older dogs from the English line in distant generations but not closely related) and an American outcross the coi of the resultant litter dropped to 3. something.

A one generation outcross using the TWA testmating can show any breeder the route to take to lower coi successfully and significantly with truly quality dogs you can admire.

Check before you breed.

To my knowledge there are no KC rules and none are planned at this time. What I can say from running coi on the TWA database of more than 110,000 dogs is that the whippet is an incredibly diverse breed and the coi averages of most of the breed are very low and of no concern. Dogs found world wide in significant numbers in many countries help keep coi low as there is so much genetic material that is unrelated over many many generations and so you will find coi rates are generally very low (under five) for vast numbers of whippets, including show whippets world wide.

A lot of people think working whippets are immune to higher coi, but as someone who has entered nearly 8,000 English whippets on the TWA data base I can tell you as I enter and check coi at the same time, that some of the dogs doubled or tripled or quadrupled up on some of the desired bloodlines of the past from the working lines, that there are cois well over 20 in some of the working dogs too, so everyone concerned needs to look, no matter whether your dog is show or working.

In Sweden there is a registration requirement that all dogs (of all breeds) eligible for registration must have their coi under a set amount. However the qualifying amount is just 5 generations. There are a huge number of dogs who can go five generations with no common relatives in generations one through four, and a significant number who can even go 5 generations, but the real test of coi comes, in my view, when more generations -- but not ridiculouly more like the KC test mate which calculates coi even with missing generations on some of the dogs -- such as 7 are computed.

Scientists will tell you after 5 to 7 generations heritability of anything from ancestors prior to that drops like a rock, so a 7 generation coi gives you a very good snapshot of the dogs that may contribute things good and bad to your living dog or its descendants.

Hope this helps. If you need more info let me know.

Lanny Morry

 

[JAX]

The whippet archives as from early July,2011 contain 10 genereation pedigrees together with percentages relating to the coefficient of inbreeding. Could some member of this forum supply reasonable guidlines as to acceptable C.O.I. percentages. Would it be correct to say that a dog with a C.O.I of say 25% mated to a bitch with a C.O.I of 25% would produce offspring with a C.O.I. of 0.00% providing there is no dog commom to both pedireees.? If both parents have a C.O.I. of 0.00% and there is no dog common to both pedigrees would it also be correct to assume that that the offspring would have a 00.00% C.O.I? Has the Kennel Club laid down any rules under which a litter with a C.O.I exceeding a certain percentage would be refused K.C. registration?. Mathematics has never been my strong point although I did manage a pass at "0" level and later qualified as a certified corporate accountant. Looking forward to your comments. Netheredge

Greetings, I am one of the team members of TWA and think I can answer your questions.

In answer to your first question, would it be correct to say that a dog with a high coi bred to a bitch with a high coi would produce offspring with a lower coi providing there are no common dogs in the pedigreee, the answer is yes, especially if there are no common dogs in the first four or five generations. After that it becomes more difficult, if the dogs are from the same country and same basic gene pool not to have at least some common ancestors. For the record, we own an English Ch. whippet with a coi over 25 because she is tightly linebred for multiple generations. I chose her and testmated her to the English whippet male from another kennel who has, to my knowledge, the highest coi of any English whippet I have seen... higher than our bitch -- in fact for 7 generations it is at or over 30. The coi of the children dropped to 15, which may still be high for some people but it not unacceptable compared to being over thirty.

In actual reality when we bred our bitch to a male that we imported from Finland who carries our earlier breeding from the late 80s (containing some older dogs from the English line in distant generations but not closely related) and an American outcross the coi of the resultant litter dropped to 3. something.

A one generation outcross using the TWA testmating can show any breeder the route to take to lower coi successfully and significantly with truly quality dogs you can admire.

Check before you breed.

To my knowledge there are no KC rules and none are planned at this time. What I can say from running coi on the TWA database of more than 110,000 dogs is that the whippet is an incredibly diverse breed and the coi averages of most of the breed are very low and of no concern. Dogs found world wide in significant numbers in many countries help keep coi low as there is so much genetic material that is unrelated over many many generations and so you will find coi rates are generally very low (under five) for vast numbers of whippets, including show whippets world wide.

A lot of people think working whippets are immune to higher coi, but as someone who has entered nearly 8,000 English whippets on the TWA data base I can tell you as I enter and check coi at the same time, that some of the dogs doubled or tripled or quadrupled up on some of the desired bloodlines of the past from the working lines, that there are cois well over 20 in some of the working dogs too, so everyone concerned needs to look, no matter whether your dog is show or working.

In Sweden there is a registration requirement that all dogs (of all breeds) eligible for registration must have their coi under a set amount. However the qualifying amount is just 5 generations. There are a huge number of dogs who can go five generations with no common relatives in generations one through four, and a significant number who can even go 5 generations, but the real test of coi comes, in my view, when more generations -- but not ridiculouly more like the KC test mate which calculates coi even with missing generations on some of the dogs -- such as 7 are computed.

Scientists will tell you after 5 to 7 generations heritability of anything from ancestors prior to that drops like a rock, so a 7 generation coi gives you a very good snapshot of the dogs that may contribute things good and bad to your living dog or its descendants.

Hope this helps. If you need more info let me know.

Lanny Morry

Most of this has been on TWF / Lanny is an ordinary poster as are alot of folk.

When breeding IMO you should use the dog that will compliment your bitch and what ever your bitch is lacking , find in the dog , no COI will do that for you. JMO

 

[Avalonia]

Most of this has been on TWF / Lanny is an ordinary poster as are alot of folk.

When breeding IMO you should use the dog that will compliment your bitch and what ever your bitch is lacking , find in the dog , no COI will do that for you. JMO

Jax, actually I AM a member of the TWA team and have been for several years and I was amongst the group those who test drove the coi system now on TWA for several months before it was launched and was active in consultations in this issue before the launch.

All this said, in my view coi is only one number of factors one could/should consider when breeding whippets. We have owned whippets for nearly 30 years and bred them for more than two decades (we were involved in whippet rescue and took in and homed five dogs needing homes during the time we took time to learn about the breed before rushing out to breed a first litter) and our critieria have always included the demonstrated health and vigour of a bloodline, based on the ancestors, and the qualities we most admire in whippets -- including correct conformation, size (we breed to English standard not the American one which produces bigger dogs with unusual toplines and croups), temperament and longevity. We have linebred sometimes very tightly throughout our entire breeding career (our being my son Mick and I) and we continue to type and linebreed, using well constructed dogs from other bloodlines that are compatible with our type. Coi is only a tool in a breeders arsenal and nothing replaces a really good eye, a genuine appreciation for breed type and quality, and a knowledge based on experience of seeing firsthand over an extended period of time of how linebreeding works best -- all this based on a very good knowledge of the breed generally and dogs in the line used and brought into the in the linebreeding program, as well as those brought in for the requisite outcrosses that must accompany linebreeding.

I certainly still do not believe that coi replaces anything such as the eye and knowledge of the breed and the dogs in a bloodline, good and bad, of a of a good and conscientious breeder committed to the breed and active in it for an extended period of time, and who has a vision and follows it.

Coi will certainly not be the instrument we use to determine the next sire of an Avalonia litter, and it won't be the instrument we base our decision on when we breed our next litter because we can rely on decades of knowledge we have built up of the lines we have relied on and built our breeding program with. No mathematical formula can replace what you see in the results produced from an active planned and carefully built breeding progam. But that comes with time, and more than one or two litters.

If nothing else the coi system provided by TWA shows all owners and breeders and would be breeders planning for the future who the ancestors are who have made the dogs they have on their premises that they are planning to breed, and that allows breeders a further tool to analyze the qualities their dog they plan to breed may have captured from ancestors, and it may also therefore suggest routes forward -- especially trying a test mating analysis -- in a breeding program based on what you learn about what those ancestors might have brought to the table in breeding programs of other dogs where they are appear and not just your own.

In my view, nothing, positively nothing beats having a good eye, a clear and consistent vision of the breed past, present and looking to the future, and the knowledge that comes out of watching and observing a breed for a long period of time that goes with most breeders who have elected to make a long term commitment to the breed. Mentors - people in the breed longer than a minute or five years -- such as those we had in our three decades in whippets are worth their weight in gold because they can be everything from sounding boards of ones ideas good and crazy, to reporters with recall who can remember and describe the best and the worst they have seen, and tell you why, based on a lifetimeof living with and loving the breed. For those new to the breed, a good mentor can simply be someone to bounce ideas off and one who can encourage you to think through decisions about what you are looking for before you breed.

There is enough daylight now, so I have to run and let my boy dogs and our boarders out for their first run of the morning.

Ciao for now.

Lanny

 

[chelynnah]

No disrespect intended, I'm just a bit confused...

Most of this has been on TWF

So what if it's been on TWF - not every member here is a member there and vice versa, so no reason information can't be posted on both boards. People have been complaining that this board has been so quiet, so why not start a conversation here even if it's been covered on a completely separate board?

Lanny is an ordinary poster as are alot of folk.

Lanny is an ordinary poster here, and on TWF - however she was stating that she was a team member of TWA' - meaning a Team member on THE WHIPPET ARCHIVES. So I'm not sure what your point is or if I'm missing something?

As for COI and the original question - I personally believe it's a really helpful tool to be used in conjunction with all the other tools in our arsenal - be it our own knowledge, utilising the knowledge of those who've gone before us, studying, learning. As Lanny said, I don't believe it replaces anything, and I would never do a breeding solely based on COI, however I do think it is a useful tool that can be used in a myriad of ways.

Wendy

 

[netheredge]

Thank you all for your interesting replies. Kindest regards, Netheredge home of Veredon Lovey Dovey, Broadacres Sobbin and three old ladies