gizmom":1l8uy5od said:
The association list potential carriers as an FYI. In the case of OH M1 and DD you do not have to test you just need to be aware not to breed a OHP bull to a OHP heifer.
https://www.angus.org/pub/OH/OHFactSheet.pdf
https://www.angus.org/pub/M1/M1FactSheet.pdf
https://www.angus.org/pub/DD/DDFactSheet.pdf
Hopefully the fact sheets will answer some of your questions.
gizmom
Thanks. I have read them all previously. The new one, OH, just snuck up on me. They don't seem to have given it much fanfare, unlike the prior ones.
I tested for DD because in my one or two that were DDP, it was due to a long-ago ancestor and I figured they were probably clear. One cow was NHP, though, and she turned out to be a carrier so we have to test all of her heifers (haven't gotten any males from her but they would be steers anyway).
I just don't know how/where this ends. I have a background, of sorts, in biology, including some genetics. The more they dig, the more they will find. I worry that we may lose a lot of unknown positive benefits and end up with a small gene pool if the current trend is followed to its logical conclusion.
Too, AAA "says" that testing for OH and DD is optional, but if you are selling replacement heifers, you either have to explain to buyers that those ominous words on your reg certs "don't mean anything, heh heh heh", OR you test them and run a very real risk that now your animal bears a DDC or OHC code instead of just a "possible" code.
I have zero problem with them doing this on genetic defects that are of serious concern. But light eyes?!
We need to keep in mind that some "defects" carry other, surprising positive benefits. For example, "sickle cell" in humans confers some protection against malaria. See, eg,
http://www.cdc.gov/malaria/about/biolog ... _cell.html.
Nesi, AAA says the defect is cosmetic: "While some affected calves have sensitivity to
light, they are believed to be otherwise normal functionally and physiologically." (So, only a portion of the affected calves have some light sensitivity. Keep in mind these are "affected" calves, not carriers or possible carriers, who are totally normal).