Hannah, our yearling, had tiny teats when she first freshened. It was a three finger milk job so I left her doelings on her and they stretched them out. Of course my three fingers kept milking her out once a day to make sure she was emptied until the kids did their job. Then I have kept milking as the two doelings have a favorite side emptying one more than the other. Recently I've noticed that Now one teat has become longer than the other. Not quite what I had in mind. I'd say it was the kid's fault but I know better as it has never happened before and I've had dairy goats 33 years. It must be on the bucks side and something genetic. I'm not as familiar with his relatives. I'll blame on him anyway as that sounds as good a reason as any.
I always say, "Pretty is as pretty does." for I've had some goats with pretty udders that were not fun to milk and I'm not talking about their personalities. Leah was just such a goat. That girl had looks but it took all my strength to squeeze milk out of her. Not fun! It seemed like a competition between her keeping it in and my trying to get it out. Milking her took time and all my strength leaving my hands cramping and the end. The problem was orifices that were too small. An orifice is the hole in which milk comes out. You can not imagine how many times I wanted to take a hot needle and poke a bigger hole. Would it have worked? I wondered. But I'm sure Leah would never had let me come near her again.
Too big an orifice hole and the doe is susceptible to mastitis since it leaves a wide open space for bacteria to crawl inside. Too large a teats in circumference and it is hard to grab a hold of and squeeze. It also makes it hard for kids to put the teat into their tiny mouths to suckle. Too small and the funnel has little area for the milk to pool before coming out and it takes more squeezes.
Another thing you can not tell from the show ring is the exact placement of the orifice hole. Orifices are not always placed at the bottom of the teat. If not, you have to turn your wrist so as to aim at the bucket and it takes a bit of practice. Sometimes I get a doe with just one side that goes askew, and sometimes it shoots off in odd directions on both sides. That takes a little finesse. A new doeling does not appreciate your squirting her in the leg or belly until you get the hang of it. Even when you do, you'll still mess up on occasion. I do anyway.
You don't want a doe with teats too large because it is hard to get a good grip. Too long and they are likely to get caught on fences and rip. So like Goldilocks, "not too big and not too small" is best. It is also a bit of preference. I know people who like larger teats and as for myself I don't. My hands are small. And of course you do not want does with more than two teats. The extra or extras may not function but they might and anyway they are not a genetic trait you want to pass on. These are things one often does not pay attention to when buying a doe but since you have to deal with it so often, it pays to check it out before you hand over the money. For a little more visual reference on correct teat placement, I've added the ADGA sites page on udders. But I'm curious, what do you have in your barnyard?http://adga.org/seeing-a-dairy-goat-by-the-numbers/