Here is a Fact Sheet by AAA on the Angus DD defect:
If you purchase ANY Angus
commercial or PB cattle (even crossbreds) you are taking the chance of several defects in the breed. Not bashing - just facts. AAA does
not require a breeder to test anything. You can run a DNA test on your heifers (not sure, but don't think it's very costly - maybe $45???). Not saying ALL Angus cattle are of high risk - but, evidently there is a good population around you that are carriers. What is the chance you purchased two unrelated animals and both are carriers?
LOL - now are you ready to try black Simmental (required to be tested if Angus or Chianina or Shorthorn or Maine, etc) genetics are used to create the offspring in question.
LOL - I'm being a smartazz.
Back to your replacement heifers. If you would like to keep them, just test them. If they test clean, your good. If 1 or more test positive - you can ship or keep as long as you test the sire you plan to use.
In the Simmental breed, if an animal tests positive, you still have the right to register them, but the genetic defect is put on their registration