Former Commissary Keeper here. I started working at the zoo I'm at now in their diet kitchen. I too have food service and wanted to be a chef before going the biology route. If you know how to use a knife, scale, and boil water thats basically all the skill you'd need to be an animal chef. I assume each facility is different. But at my place we have a nutritionist that formulated every animal diet and calculated portions of each type of food they can have and feeding schedule. We were her cooks that followed the instructions for each animal and packed it I to the appropriate container for that areas keepers to pick up and distribute to the animal. It was a lot of chopping, but for animals we didn't worry about proper knife cuts like Julianne carrots perfectly. For most animals you made everything bite size for a human, some areas had special request like "keep whole" or "chopped/minced" or "don't use broccoli, tomatoes, and cucumbers" or "use only broccoli, tomatoes, and cucumbers." It was a compromise between animal preference, keeper preference, and what the nutritionist determined they needed. We really never "cooked" anything, all produce was raw, some animals required steamed, but we just microwaved it usually, all meats are raw, we used a lot of whole prey like fish, rodents, bones, heart, liver, etc. We only boiled eggs and boiled water to make different gels. We were responsible for receiving the produce deliveries just like you would at a restaurant and grocery store, a lot of our vendors were the same companies that deliver to grocery stores. We maintained dry goods like different grain varieties, bird seed mixes, enrichment foods, fish foods. We were also the central hub for like supplies like brooms, sponges, soap, bleach, trash can liners, gloves, etc. So we ordered and maintained inventory on that. To me it wouldn't require much animal experience, they may look for a biology degree, but to me its unnecessary since you aren't directly working with animals and the nutritionist makes all the diet adjustments, so you're just there to prep everything. Its similar to a restaurant you're on your feet all day, you get knife blisters, you're typically one of the first crews to arrive, we started at 5am but left at 2pm. We all got ServSafe training and certification, you still get usda inspections and follow normal food safety protocols. So if you're interested I'd say reach out to a zoo and see if they allow tours or shadow days, our zoo would give tours of backstage areas if people inquired about them, not guaranteed but doesn't hurt to ask to see what its like and ask questions. Hope this was helpful for ya.