Food and measuring food

Looks like the time vs. time of day typo really was the big issue. The lesson of this story: never blame other people before checking over your own work very, very carefully. And don't leap to conclusions about what's broken - it's likely something very silly.

I can't quite wrap my head around how I want to do hunger yet. A lot of animals, especially grazing animals, seem to eat a lot. That is, they'll kind of hang out and nibble for a lot of hours. So they need regular access to food, and aren't going to eat the few pounds of hay/grass in one minute-long turn.

I'm tempted to say that the sheep will need access to adequately nutritious pasture for a certain number of hours a day, or they'll need a certain quantity of supplemental feed (probably in the barn). This gets a little dicey, since it requires looking at some hard numbers and deciding how I'm going to handle weights and measures and stuff. Since I don't quite have that crystallized, I'm going to work on some other stuff for now.

Before I handle harvest-type things, I need to set up a basic weights and measures system. I've got the most basic weight and volume set-up now, but it's not up to handling hay harvest, much less apple harvest. Part of the difficulty I'm having is that the measures are radically different across the world, plus there's some weird farm measures, like bushels.

I considered breaking this down to "meal-units" - the amount of food a person would reasonably eat in a sitting - but I think that's too vague and variable. Some of the factors I'm juggling:
Storage - Assuming the player will set aside space for storage of foods for both people and animals, what does that look like? What's a bushel of wheat vs. a sack of wheat flour vs. a "pile" of hay? (How big is a ton of hay, anyway?)
Quality - high quality hay has more nutritional value than low quality hay, and in real life, an animal fed high quality hay will eat less of it, and/or require less supplemental feeding
Carriable/describle quantities - I want the character to be able to visualize and handle the quantities of food we're talking about, without fine tuning. So not "You feed 2.5 grams of wheat to the chicken. She's thrilled!" but "You scatter a handful of grain for the flock." How much hay does a sheep eat a day? An armful? A flake? Half that? Would there even be hay flakes if there's no baler?
Different kinds of foods and equivalencies - does it matter if you give chickens cracked corn vs. wheat? What about sheep on turnips rather than alfalfa?
Calories - I'm not planning on handling detailed caloric intake for the animals - probably just quantity of certain foods - but I am considering it for people-food. Eating three solid meals of spinach a day is not the same as eating three solid meals of bread and cheese. Basically, this is an extension of food equivalencies.

A lot of these issues are solved for animals if I can figure out pasturization. On the other hand, I can't assume players won't try grain-only diets for the sheep, so there needs to be some back-up systems in place. I'm not really sure how to program the different factors, so I'm setting it aside for now while I turn over different possibilities. I think if I have a clear conception of where that piece needs to go, it won't be too ugly to slot it in a bit later.