Mandatory Spay and Neutering of pets

What are your thoughts about mandatory to have pets fixed ? Having a mandatory pet registry? To start, (this is random and just throwing ideas out there) Pets would be required to be registered with your city county or state (whatever) . Pets under a certain age that are not fixed would be required to be fixed. To breed, you would have to be a registered breeder. Every pet owner would receive a tag for their pet, that can be scanned for identification purposes.