it should be a very rare treat, mine get a bite of cheese every once in awhile and love it. of course always watch your ducks and make sure they are acting normal after trying anything new.You may want to reconsider recommending dairy. Birds are known to be lactose intolerant, and unable to digest dairy well. Since they were never nursed by their mothers, like mammals are, they never developed the need to digest milk. More than one avian veterinarian has told me to avoid even the tiniest amount of dairy found in probiotics for my ducks.
That being said, I do know members who feed their birds dairy and their birds haven't dropped dead. But it could be causing digestive issues, like it does with humans, and their birds can't communicate the problem.
@Chickmgnet I am unaware about garbonzo beans specifically, I keep meaning to ask my vet. I admit my bad ducks are obsessed with stealing my food. I swear one distracts me with cuteness while the other lunges onto my plate. They have swiped a black bean before, and multiple times, tofu. They have also plunged their bills right into my soy milk. The soy bean product has to stay above duck bill level at all times.