I can't forget the chicken in Beastars (similar show to zootopia but not for kids) who sells her own eggs to other students and is proud of it.

There are human farms.

Bull milk

We have three options here:

All dairy products are actually non-dairy equivalents that happened to just take the original names.

There are equally intelligent milk-producing species that either keep themselves in a milk producing state or are otherwise forced into said state.

Or

There is an unseen slave caste of lesser intelligent members of species that are harvested for their products.

They keep humans as livestock.

Maybe it’s like Beastars where animal products like eggs are just a pretty normal type of labor

Zootopia? Based on what I've seen online, who's getting milked? Anything that moves.

Probably the femboys

There isn't ice cream. They sell water based flavoured ice. Don't know what the English word for that is.

I've had some non dairy ice cream that's pretty good

The almonds

Also why does Mickey Mouse keep Goofy's intellectually disabled relative as a pet? It's the sort of messed up thing I'd do, but not suitable for a children's character.

Vegan?

No, no, ...

The question (and shorter answer) is who isn't getting milked.

We have human milk ice cream, why do you think it’s weird in Zootopia to have milk from other mammals