Friday, 16 March 2012

inbreeding coefficient

Firstly an apology as my blog is still getting so many hits a day and I have been just too stretched for time to update.
I spent two days at Crufts, and was lucky enough to spend time with the experts from the Animal Health Trust talking about conserving a rare breed. Basically if you are conserving a breed or any type of animal then you make sure that you always as near as possible to 0% for the coefficency of breeding.
To try and explain, this was written by John Armstrong of the canine diversity project.

Percent Contribution

If sufficient data is available, one way of determining the significance of an ancestor is to calculate his percent contribution to the current dogs. The % contribution (aka percentage of blood) is determined by the way genes are passed from the parents to the progeny. An individual inherits one set of chromosomes, and the genes they carry, from his or her sire and a second, homologous (equivalent) set from the dam. Thus, each parent makes a 50% contribution. As the parents in any generation always contribute 50% of their genes to their progeny, it seems reasonable to expect that 25% will come from each grandparent, 12.5% from each great-grandparent, and so on. However, once we are past the parents, we are dealing in probabilities, not certainties. This is not like mixing paint! When dad passes you one set of his chromosomes, they will include a selection of ones inherited from both his parents, but there is no guarantee that the selection will be exactly equal. There is even a small chance (very small) that he will pass on those from only one of his parents.
By the time we get back 10 generations, the contribution from each of the 1024 ancestors would, in theory, amount to slightly less than 0.1%. However, in the pedigree of the average purebred dog, there are seldom more than 100-200 different names and some appear 50 times or more. These are the significant ancestors that make the major genetic contributions.

So 0% for conserving a breed, almost impossible with a genepool so small for the barbet. However it is worth thinking about if you are buying a puppy, ask for the inbreeding coefficient.
However this is only one of many things to check before you think about buying a pup, but its something to be aware of. If it were foolproof for genetic problems/epilepsy/hip problems and all the current diseases that dogs suffer from then vets would never see dogs such as first crosses (F1) in their surgeries and sadly they do. I have owned three complete crossbreeds, one died at 4 years old of cancer, one died at 7 from a heart attack, the love of my life died at 10 years old of liver cancer, they were all the result of 0% inbreeding. My two pedigree dogs, one a standard poodle who is very much alive at 11 (12 years old next month) and I owned a Cavalier King Charles Spaniel who died at 10 years of old age.
So if buying a pedigree dog, ask the question and write down the result, confirm also over how many generations the % was calculated.As a guide, The Swedish Barbet Club has issued guidelines over registration for their club members, and that is less than 9% over 5 generations.At the moment the next two litters expected in the UK very very soon, so I am very excited are under 9% over 6 generations. 
Its important that breeders in the UK are open and honest and the information about the dogs freely available. If Barbet puppies are advertised on free puppy sites, then please check health reports are available from the breeder, and do check the source of the barbets, remember I am the owner of a fake barbet, bought from gumtree several years ago. A good quality barbet with good health reports and all the paperwork will not be found by surfing for puppies. The breed is still in its foundation stage in the UK, these things take time,but with our record of hip scores (available on the GB site) we are heading in the right direction. It was a good moment for me when I took a rehome boy into my vet with a lump in his ear, I thought it was hair but it was going to be a two man job as no way was he going to sit still, and at the back of my mind, maybe it was a growth or something similar. My vet had a look, and asked me to book him in for a general so he could deal with it, well....I don't like generals on dogs and a vet is a vet, they should have a better look before they decide to risk a dog with a general, so I made my feelings known   politely and scared the vet BUT he looked at my records again and said '' of course these are your barbets, let me get the forceps and see what is down there, most breeds I would not dare to do this but your barbets are always beautifully behaved'' so he disappeared and  returned with forceps that almost made me vomit as they were huge!, this beautiful boy sat there and had a hairball removed from his ear that I should have taken a photo off, it was rock hard and must have been uncomfortable and he didn't make a sound. So the barbet reputation at my vets is still 100%. Apologies as I have digressed as I was thinking about the charactor of the breed, so the above piece was my thoughts.