Horse grain is pretty good, actually. And my friend gave out her dog's jerky treats to us guests (not bad, a bit bland). I ate some of my foster parrot's food because it was that colored stuff that isn't very good for them, and I tested it against the Harrisons- you could definitely tell. It was like sugary cereal versus the 'colon blasters' as my mom calls them (high fiber).
And if you ever get the chance- panda chow is SO GOOD. When I was working at the one zoo we had a red panda (cute but flexible and nippy) and we would snack on that panda chow at all the meetings.
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On the other end of the spectrum my cousin tricked me into eating "animal crackers" that is, dog treats made to look like the cookie of the same name. They tasted sort of stale, but I was hungry. My aunt came in and gasped, grabbed the bowl of dog treats and started yelling. hehe.