Changing how animal diets are handled in the game would, I agree, be the best and most interesting way of adding management to the game. I would have thirteen major food categories, which could in turn have smaller sub-categories within those. The thirteen major categories would be:
- Dried Forage (hays)
- Browse (cut fresh branches)
- Produce (fruits and vegetables)
- Concentrates (pelleted diets for herbivores)
- Meat (mammalian and bird meat)
- Fish (marine and freshwater fish)
- Kibble (pelleted diets for carnivores)
- Seeds (includes nuts as well)
- Eggs (bird eggs)
- Livefood (live invertebrates)
- Specialist diet (pelleted or powdered diets for specific animals, such as insectivores and flamingos)
- Enrichment (food only used in enrichment items, and as such a marginal part of the actual diet)
- Supplements (vitamin and mineral supplements)
So, these are a few examples of what I could envisage being sub-categories within these major food groups:
Produce
- Leafy vegetables (such as lettuce, spinach and kale; cheap but large quantities need to be purchased to feed a larger animal until it is full)
- Watery vegetables (such as celery, cucumber, beans and corn; cheap and often highly palatable)
- Root vegetables (such as carrots and turnips as well as squashes; cheap but often quite high in sugar, so should not be massively important in the diet)
- Temperate fruits (containing citrus fruit, apples, pears and stone fruits - cheap but very high in sugar and not especially healthy)
- Berry fruits (cheap and high in sugar, but in smaller quantities can be good for many animals)
- Tropical fruits (things like bananas, pineapples and papaya - more expensive and again high in sugar, but is necessary for some species)
Concentrates
- Grazer pellet (very cheap, and useful for feeding grazing mammals such as zebras, white rhino, bovids, caprids and most antelopes)
- Browser pellet (relatively expensive, but is necessary for feeding giraffes, okapis, black and Indian rhinos, some antelopes and tapirs)
- Elephant pellet (expensive, but a necessary part of the diet for elephants)
- Pig pellet (very cheap, but only suitable for feeding to the wild pig species)
- Macropod pellet (relatively expensive, but useful for feeding kangaroos and wallabies)
- Leaf-eater primate pellet (relatively expensive, but necessary for all current in-game primate species)
- Panda cake (very expensive, but is a necessary part of the diet for both giant and red pandas)
- Ratite pellet (relatively cheap, useful for feeding all the ratites)
- Poultry pellet (very cheap, but only really useful for feeding the peafowl and cranes)
- Tortoise pellet (relatively expensive, but is useful for feeding tortoises and iguanas)
Livefood
- Cricket (easy to breed and cheap to source, but are fairly small so more are needed to sate the animal)
- Locust (easy to breed but more expensive to source, but larger and so less are needed to sate an animal)
- Mealworm (easy to breed and cheap to source, but not particularly nutritious)
- Soldier fly (takes more time to breed and more expensive to source, but very nutritious)
- Earthworm (easy to breed and cheap to source; particularly useful for birds like the peafowl)
- Field plankton (free to source, but needs appropriate habitat on the zoo grounds - for reference, field plankton is the term for wild invertebrates netted from long grass)
Each species has its preferred diet. The species has a tab added to a special Animal Diet Manager when it is added to the zoo (I decided that this would be easier than having a different diet tab for each individual animal). The type of food can be selected from a drop-down menu, and the ratios can be adjusted with sliding scales - for example a gorilla would need about 90% vegetables (any of the three types can work), and about 5% each leaf-eater primate pellet and browse.
Some foods - all the browse plus the field plankton, can be collected for free from the zoo grounds. The browse needs the appropriate plant to be growing on the zoo's grounds, otherwise the browse will need to be purchased and brought in. If a plant is harvested from too much, it can become damaged and needs time to recover, so multiple food plants can be scattered around the area - the keeper automatically goes for the nearest non-damaged plant. So, for example, to collect bamboo browse you will need a bamboo plant growing on your zoo. For field plankton, you need an area of long grass where the keeper visits with a net and makes a few swings through it. Fortunately, this resource does not get exhausted - so long as the long grass remains, it can always supply field plankton.
As an additional part of diet management, there would be three types of feed storage building required, plus two feed preparation buildings. The feed storage buildings would be:
- Feed Storage - The largest building that does not need a power source and stores dried forage, browse, produce, concentrates, seeds, specialist diet, enrichment and supplements
- Cold Storage - A mid-sized building that needs a power source and stores meat, fish, kibble and eggs
- Livefood Unit - The smallest building, needs a power source and provides only livefood
The feed preparation buildings would be:
- Animal Kitchen - The majority of animals have their food prepared here; they can be sited close to either feed storage or a livefood unit
- Carnivore Kitchen - Specifically where carnivorous animals have their food prepared; it is best to site these near to a cold storage facility
For livefood, the keeper goes straight from the Livefood Unit to the animal's enclosure - this food needs no further preparation.
Of course, for those who didn't want to get bogged down in micro-management and wanted to focus on other things in-game, there would be a new staff member - the nutritionist - who could do the job for you if you want.
