Originally Posted by
dizzy
Ron I don't know what Ian said but it would not surprise me if a lay person such as Ian interpreted what the experts said and articulated it in the fashion that you describe.It's a somewhat course way of stating it but in essence is on the money.
Despite what VVV claims the gene pool in the US, and Australia is shrinking. 10 years after John Wallace started the trotting register in 1870 odd there were over 16000 stallions and 30000 mares in it recorded as standard. In North America there are around 900 stallions today and in Australia around 300 being used for breeding. Each stallion does not serve equal numbers of mares with a large number of stallions serving as little as one mare. The mare population numbers around 30000 in total I believe. Proffesor Goves in his book classic families identified around 3000 foundation mare families in the USA, there are only around 300 active today with the remainder being extinct. I don't know if some one has done the numbers for the southern hemisphere but a similar trend could be expected.
In todays North American standardbred due to popularity of certain lines and the loss/culling of others the herd is very heavily populated with the descendants of the most popular stallions, Abercrombie largely through his sons Artsplace and to a lessor degree Life Sign and Albert Albert and of course there are others. As VVV points out the Meadow Skipper lines is very hidely spread through out the population but most of it through the descendents of his most successful sire son Most Happy Fella and then through his son Cam Fella and grandson No Nukes and their very successful sire sons. In other words the breed is becoming very heavy infused with the blood of relatively few horses.
Despite what VVV thinks inbreeding depression is real and encroaching on our herd. The most common characteristics of inbreeding depression are a reduction in size, declining fertility and a compromised immune system. For those that don't believe me or believe that these things result from inbreeding/intense line breeding go and ask a cattle or sheep farmer who breeds for the meat market. They are very aware of it as size is a critical function of the profitability of their industry, unlike ours.
As to Christian Cullen he has no Abercrombie blood, no Cam Fella blood and no No Nukes blood thus his importance in opening up the gene pool some in North America. Unfortunately he wasn't extensively used. Now despite what VVV thinks inbreeding does increase the risk of a genetic mutation happening, or it can just happen spontaneously. The end result is if it was a mutation that caused a very negative outcome in the herd such as the diseases I mentioned previously, and there are a least 4 more in Quarter horses, 6 in Arabians and another bunch in coloured horses. Just because it hasn't happened to us yet doesn't mean it cant. Perhaps it already has, many of the genetic diseases in the other breeds cause late term abortions and early death in foals. The quarter horses and arabians know because both breed registries contribute large sums to genetic research. To the best of my knowledge we don't contribute any money to genetic research, we just have people like VVV lamenting the low live foal percentages each year. Heres where VVV says but its still simalar to years ago, it is but how much has neo natal foal nursing improved?
Not all genetic mutations are unfavourable to the breed though. Just to prove to the likes of VVV that it can happen, remember Art Majors white colt in North America earlier in the year and Courage under Fires near white colt this season. Both of those are the result of a spontaneous gene mutation, which in this case just makes them a pretty colour. If either were to stand at stud then we could expect a number of their foals to also have the mutation and be white or near white in colour.
And of course if it wern't for the DMRT3 mutation we wouldn't have a breed or an industry.
VVV just because there hasn't been a horrendous disease show up yet does not mean that it cant, I am sorry that there isn't a 101 version for dummies written yet on this stuff because then perhaps you would better understand.