I have learned so much from this forum. When evaulating hips, how much emphasis should be placed on ZW ratings? Can this number be looked up online? Also, how important is an "a" rating over an "a-fast normal" Thanks for the help.
I think, dogs that were imported to the US, the ZW number doesn't get updated unless the have a litter that is registered with the SV and the litter when old enough are Xrayed and submitted to the SV for certification. I might be wrong and if I am Chris or someone will straighten me out.
The a1 (a-normal) verses the a2 (fast normal) to me isn't as simple as just looking at the particular rating for the dog. I want to know what is behind it and also siblings and half siblings. I would always prefer the a1 on the hips and normal elbows. Elbows to me are every bit as important as hips. But I would and will look at an a2 (fast normal) and check the pedigree and see if I am comfortable or not, this can be different depending on if you are buying a pup in hopes of a future breeding prospect or a great companion and some sport type work.
I'm not Chris, but....the ZW number is a tool...not all dogs x-rayed are entered in the system though so it can be skewed. People may take a look at a young dog's films, things do look so good, that dog isn't submitted then.
If you import a dog, their ZW can still be effected by how littermates are producing in Europe that are in the system; or if the dog imported has had progeny in Europe who are now entered in the system with their hip ratings. There are dogs who have been entered into the system, lets say bred in Belgium. I believe those dogs are automatically assigned a 100 which is the breed average..so those numbers can also be off.
Like I said, it's one tool to use...look at the pedigree for hips, then the siblings of your breeding pair for the hip ratings. Some combinations of breeding bloodlines can improve on hips, some don't, so also need to take that into consideration.
The ZW number really needs to be looked at as part of the whole family - the littermates, half siblings, and their progeny too. If a female is koered in Austria or the Netherlands or Belgium and only 1 or 2 of her pups get into the system and are FN, and then she has a dozen pups whose hips go A or OFA Good and Excellent...her number can be really skewed! My own female has produced 2 FNs and a Fair from one male, and from 2 other males, OFA Goods and Excellent (both adult and prelim films). Unfortunately, only the pups from the first male in Europe are done there, so the Goods and Excellent are not affecting her ZW number which would go down dramatically otherwise.
As Trish says, some dogs are known to be improvers (Aly Vordersteinwald for example) and other dogs are not improvers, and need to be bred to females with good hips and lines. Some dogs are "known" to be poor hip producers, but are producing some other trait well, so are used, but need to used wisely.