Dogs actually are pretty good for livestock too. Same traits as pigs, but breed faster.
But yes, pigs. Best way to mass produce meat. Sheep are for wool, and fuck the rest.
(Wellll okay unless you like certain animals if you specifically WANT to farm cavies then that's a good reason to farm cavies. But they're bad for food
)
I'm a bad person. I modded cavies to yield a bar of soap when butchered. 
So in my forts early on a few cavy are along for emergency first aid use.
I think soap-cavies counts as an appropriately Dwarven !!Science!! creation, so.
Can we make pig hooves count as sun berry seeds next?
No. You might be able to turn pig hooves into sun berry seeds, though. And perhaps their tails into cloth.