Yes, similar systems are also in place for eggs and poultry. And yes in all cases there are exemptions in place for very small farms, but not enough to make much of a difference.

"Alternative" products like duck eggs, water buffalo or goat's milk, etc. do not count, so there is some room for market diversification there, I guess.

It has the net effect of keeping dairy prices at what's seen as an acceptable stable level that also keeps dairy farmer's in business, at the expense of diversity in the marketplace and access to new farmers.