Breeding coefficients

[Fran Griffin]

Just out of interest, I have just been looking at the inbreeding coefficients of some of the litters currently available and have discovered that many of them are way over the breed average of 13.4  one litters coefficient is way over 25.

I am wondering if breeders are bothered that they are producing litters with these results? If not can somebody please explain to me, as a Setter pet owner why this is so?  If I was currently looking for a puppy, these kind of results would make me look elsewhere.

[Rhonda Fisher]

Greg I am a horticulturalist, I don't read Bourkes Magazine. No one I know reads it.  If you were talking Dr Harry or Hugh W current television and radio personalities that do comment on dogs every week, then it might be something to really worry about. Even the Bondi Vet would have more pull in my opinion. I will have a look though.

[eva ciechonska]

Margaret I agree with you on the excellence of Mate Select for extracting info on COI's, health testing records etc.  Just a word of caution on the number of puppies a stud dog has produced, as I have found out by first hand experience.  Mate Select does not always tally with KC's own registration records for individual sires.  This is an anomally that must be addressed before it becomes accurate or credible.  I will reirerate what I have already posted.  The addition of progeny with ATC numbers artificially inflates a sire's litter record on Mate Select.

[eva ciechonska]

I have answered Torie on Anne's discussion especially the dangers of quoting data out of context. All statistics have to be set against number of dogs bred for any particular period, number of other sires used at the time, the number of years spanning a stud dog's activity etc.etc.

As Sue says, breeding practices have changed in the last twenty years and breeders (and stud dog owners) are much more aware of the pitfalls of putting all your eggs in one basket.  Also registration numbers of ISs have fallen steadily to under 1000 in 2011 so all the more to be vigilant.

Interesting analysis from John on a simple recessive condition that can be easily eradicated.  Other conditions are multi-factorial so not quite so simple as there are often external influences.

Incidentally Susan, I know you put a high store on reducing  COI's so do your own homebred dogs have a low coefficient?

[Susan Stone]

I'm trying to reply to both Sue and Eva here so hope I don't muddle things up...

 

Sue, one point you make is that it is the responsibility of the stud dog owners that their dog is not overused. I'm not sure I agrree with you, I feel it is as much the responsibility of the bitch owner AND the breed clubs to ensure that no dogs are overused. After all, there would be an outcry if a bitch had more than 5 litters but if the dog sires more than 10 nobody batters an eyelid... ok, I know there is a health issue in a bitch and obviously she should not be exploited for breeding purposes. But does it make sense that a male can sire as many puppies as the owner is willing to allow? Should there not be a code of ethics that prevents the overuse of stud dogs?

I am pleased to hear you say that times are changing and hope you are right. In Ann's discussion on type I got the impression that the preservation of type justified all breeding methods, be that overuse of stud dogs or be it inbreeding with higher than average COIs.

As Eva says, ideally someone would gather data of the number of Irish Setters registered each year with the KC and then compare how many individual stud dogs have been used. Also comply statistics as to the use of every stud dog in recent years. I do not have the KC Breed Records Supplement but I am sure some here do. Other countries must be just as vigilant, this is by no means something that only concerns the UK. Switzerland however is a bit off target as only three litters were born last year...

 

I think multifactorial conditions are very likely to follow the same pattern that John has outlined for the simple recessive gene of PRA rcd4. But as complex conditions are by definition complex it would be difficult to proove.

Eva, you ask about my personal breeding, I can tell you that my personal breeding is on hold as I do not know which way to turn. I have sadly experienced epilepsy in three litters from different combinations, I also experienced MO and GDV in my first litter from very different lines. If I continue breeding I am thinking of a true outcross and promise to let you know when the time has come. :-)

Here are the COIs of my last three litters according to Michelle Webster's brilliant database: B-litter COI of 12.4%, C-litter COI of 12.9%, D-litter COI of 11.3%. They are all below average but still not not low enough.

It frightens me to see litters advertised with COIs over 20% and more! 

[Astrid Landsaat]

Quote: "It frightens me to see litters advertised with COIs over 20% and more!"

This frightens me too Susan.

[eva ciechonska]

Thank you for your response Susan and, interestingly I have turned down bitches for both my boys who would have produced a litter COI of more than 20%. My own litter last year has a COI of 12% but I did not deliberately set out to reduce it.  I would only ever use a COI as a a check and never let it be the overriding factor.

With respect to your personal COI's they are low and at that level do you really believe that they would have contributed to your problems with epilepsy and GDV?  It greatly concerns me that too much store is being placed on COI's as an answer to the elimination of all problems. 

[Margaret Sierakowski]

I dont think anybody has ever argued that lowering COIs will eliminate all problems, only that with lower COIs the spread of recessive gene problems and possibly also polygenetic problems would be slowed down.Genetic defects will still be present, but expressed less frequently.  Also lower COIs reduce the effects of inbreeding depression - weakened auto immune systems, lower fertility, smaller litters, lower birthweights, weedier finer boned dogs with poor dentition etc However the problem remains that after decades of inbreeding, and huge loss of genetic diversity, it takes more than the lowering of COIs to increase diversity again - the only way to do this is by outcrossing. Or by importing unrelated dogs from other countries if they can be found

[Susan Stone]

Thank you for your reply here, Margaret. I had no chance to contribute further to this discussion until now.

Eva, quite right we will not get all healthy dogs simply because a litter has a low COI. This  is not what I have been trying to say although one does tend to get a bit fixed on one subject at times.

Let me say the GDV case was from my first litter in 1984 and not linked to the B-, C- or D-litters I mentioned. I actually consider the 'classic' form of GDV (ie dogs under 10 years)  very likely to be a dominant form of inheritance with incomplete penetrance and if so would not be influenced by levels of inbreeding.

I know I am not the only one who has had problems with epilepsy and considering 'my' litters have not had an extremely  high COI it worries me all the more because it means that this kind of health issue - the ones we can not do a DNA test - are the ones that present the greatest risk to the breed. Considering that the lines I have bred from are the same ones that are prevalent in most of present day dogs, then surely it becomes clear that by continuing to breed with high levels of COI we may be heading for trouble...

It is these issues we need to be aware of and discuss openly. The loss of genetic diversity will mean that health problems such as these could become widespread even before we are aware there is a problme. It is thanks to the very simple tool of COIs that we can now visualise the lack of diversity and stear agains it.

   But if we continue to breed as we did in the past then our problems are guaranteed to increase. I think it was Dr Amrstong who was able to proove in Standard Poodles that dogs witha COI of less than 6.25% lived on average 4 years longer than those with a COI over 25%. It would be extremely interesting to have a similar statistic of comparing longevity with levels of COI in Irish Setters.

Most owners of Irish Setters are very happy if their dogs live a long a healthy life. In my experience they are not normally bothered as to whether or not their dog is of the preferred type for the show ring.

[eva ciechonska]

Not really Mel.........just going round in circles.

[Margaret Sierakowski]

Isnt health testing often about cleaning up a mess which has been allowed to happen instead of preventing it from happening in the first place? Health testing isnt enough, changing breeding practices is what will stop genetic problems from becoming widespread in a breed

[Torie Lancaster]

This has to be the most sensible comment I have read for ages and I am sure most caring breeders like yourself Margaret will agree.

[Pat Aldridge]

"Health testing isnt enough, changing breeding practices is what will stop genetic problems from becoming widespread in a breed."

It is breeders' mindsets that will need changing - I have read on this forum the opinions of some who do appear to be prepared to throw the baby out with the bathwater.  One example is PRArcd4 - using only DNA tested clear dogs in a breeding programme & not using carriers/affecteds (with clear dogs only - meaning puppies have to be DNA tested) - is one of the quickest ways to reduce the genetic diversity.  CLAD is another example of this - carriers' valuable lines were lost as many breeders wouldn't use them.  Why? 

Other breeds in the past have gone down this road of "breed from clears only" & are now in dire straits.  A lemming-like clean sweep of some of the most valuable (breedingwise) lines will only cause a bottleneck with the attendant increased expression of any genetic problems...we have the DNA tests, if we don't use them intelligently, lowering COIs isn't going to maintain or increase genetic diversity.