They already do DNA testing to register horses so it shouldn't be to different on cattle I would think. I have no experience in that area but it's just a thought.
I don't think I would bet the farm on the results or my several thousand $$$$ purchase on this venture - lots of BIG hats with information on screens - our experience left many unanswered questions that on paper didn't quite fit - just saying ---
There are several levels of DNA testing that we do in the cattle industry now. When a bull goes into AI stud or a cow becomes a donor, they have to be DNA tested and parentage verified. Not all registries require this but most do. . There is testing to see if they carry any of the genetic defects - this is required on any suspect lines if an animal is to be registered in most association - once they are found to be clear, that goes into the data base. You can test to find the genetic status of polled, color,carcass traits. Each test you add costs more of course so you have to decide if it is worth it to you.
We had an interesting mixup a couple years ago on a heifer that my daughter was showing. The cow was supposed to have been AI'd to a certain bull and that was what was written on the AI sheet but when the calf came, it did not look the part. We went back and forth on what could have happened and such and finally ended up registering the calf as a daugther of that bull. But had such a niggling degree of doubt, I requested to parentage verify her. We inventoried semen in the meantime and discovered we were off straw count on two other bulls.. so I gave them the three sire possibilities. Meanwhile, the papers came back with her under the original bull and the EPDs for her were dismal. We were going into a set of breed shows at this point with the judges looking at both numbers and the actual animal. Thankfully, DNA results showed up online with her sire being a different bull and her EPDs went from being horrible to being in the top 5% of the breed in many traits. This heifer has had a very sucessful show season. While I know that the numbers arent' the only reason, we are glad a mistake was made and that we could prove it. There were other lessons here.. DOUBLE check the straws when they come out of the tank and then when theyt come out of the cow and if in doubt at all get the calf parentage verified early.
Also, 4H animals have to have hair pulled, in the event they win a big one, hair is pulled at that show and DNA is then ran on both samples to be sure they match in case someone would cheat.