I had a pair of sisters, one has a beard, the other doesn't, the one with a beard, all her doe kids thus far grow beards too the other one, I out of four does I have kept one, and tabs on another and neither one have beards. So it's interesting we also have another doe that grows a small beard in the winter I love my girls beards
Ive never seen a dairy goat without a beard. Though does of course have much smaller under the chin beards that get slightly more full as they age. Typically no longer then 6 inches long and no larger in area then say a silver dollar. Bucks start out the same but as they age and rut it grows up their cheeks all the way to under their eye balls. Wethers will have beards more like does. The earlier you wether a boy the less hair and horn growth they will have.