I don't know that there is any official amount designated
anywhere. Lots of folks saw they should not have any at
all. They are high in fat so you have to be mindful of
that. But the real danger from them is the possibility of
them harboring the spores that can lead to Aspergillosis or
other respiratory issues. This danger exists because they
are grown underground so are at risk of having mold, etc.
inside the shell. That said, I do allow my Grey to have
about 3, maybe 4, per day. But I am also extrememly careful
where they come from, the cleanliness of them and just
generally "how they look". I realize I may be shooting craps
with it, despite how careful I am. But he loves them so, he
gets them and I just continue to try to be as vigilant as
possible. I'm not going to tell you what to do. You have to
decide but I hope this helps.