Well, I looked it up so here is some info: "The release of eggs in female rabbits is triggered by sexual intercourse, not by a cycle of hormones as in humans. Contrary to popular belief, the rabbit has a cycle of mating receptivity; rabbits are receptive to mating about 14 of every 16 days."
So bastically when a rabbit reaches adult phase, it can mate every 14 of 16 days. Compare that to other animals that usually have to wait a year . And transfer that to a world of sentient animals. Basically… condom companies in zootopia are swimming in money.

This comic comes to mind