"Cattle from an area in central asia" - oh wait that's Mongol Cattle...
I would say a mongrel cowherd is part camel, part cow, part bison, part etc. and you can't figure out which part came from where.
I think there is a place for some variation in the seedstock business, largely because it takes SOME variety to bring customer herds to their specific needs. I don't see crossbred cattle as being mongrel when it is done with a good plan in place. Actually that applies to seedstock too...
There is a big difference in my mind between putting together a bunch of cows and putting together a COWHERD :!:
The EPD subject interests me. If you put a lot of pressure on breeding curvebenders with EPD, in general you will actually tend to increase inbreeding/genetic variation in the population.