Where did this come from?

Born today, a little miracle - but a very odd one on this farm!
Yes, I know recessive genes manifest themselves occasionally - but I have never seen a calf like this on our farm in 30 years of breeding! Maybe it's Shorthorn? That's the only Non-Red semen we have ever used to AI our Hereford herd. And usually that appears as just an odd spot of white on the legs of the normal Hereford markings. Even odder, I did NOT AI cows last summer - we let our bulls do things the way nature intended. I thought both our bulls were full-blooded (or nearly so) polled Hereford. What do you think is going on here? Well, at least this little one will be easy to spot when his mama has hidden him out in the pasture - and doesn't remember where she put him!