I don't know about any certification but I can thoroughly recommend ducks and chickens for eggs for your own use.
The kids would
love looking after them and it might prevent them begging for other 'pets'.
All you need is a hut with a perch or stand for them to sleep on at night, and a nesting box to lay their eggs inside it, some straw for bedding, a water container,a food container. And kids old enough to feed, put in water, collect eggs, and help clean out the shed. Oh and a fence to keep other animals out - dogs and foxes for instance.
Cats don't seem to bother with them.
Anne