Those pigs need to be fed to stay alive. In a zombie apocloypse i doubt people will be handing out their livestock. Wild animals should be limited to promote breedin, an underused used task in rpgwo. You could also give animals levels up to level 10 etc, giving them different food qualities through breeding, giving you the choice of killing some for food or keeping some to breed.
Everything on the mainland will be infected such that it is either a zombie or a mutant, including livestock. Anything zombie is dead, rotten meat and useless to sell or eat. We could have it poison a player if they desperate to eat it. Mutants are able to be saved but need a cure injection. Once back to normal, they can be bred and slaughtered for meat safely. Plus they would need a cure shot every so often to keep from being reinfected similar to players. So, only the successfully, dedicated player will be able to afford doing this.
Keep in mind, the market on Haven (about 1000-2000 people) will have various needs and wants from players on mainland. So the value of items will rise and fall with supply and demand. Fresh, safe meat I think will always be in good demand though, so ranchers should do well and earn plenty of credits to buy more cure, maybe even a cheaper livestock only cure.
I also dont know how you would implement scavenging. I disagree with adding an item spawn like in rpgwo v1 and v2 quests, where you could just camp a spawn for hours and get an item.
Scavenging isn't the right word but it is kinda both, split up...
Salvage : Use crowbar on car wreckage to get scrap iron. (the better your skill the better items can be salvaged like an engine, radio, etc. I think it will popup a list of all the items you see in the wreckage but depending on your skill is what you can actually pull out)
Forage: Search trash pile to find plastic water bottle. (the better your skill the better items are found, random somewhat)
The spawns for these and normal item spawns should be limited so you can't camp them. But the problem with limited spawn count is all the beginning players will get all the goodies and anyone that shows up later will have nothing or have to venture out farther at greater risk to find anything thus newbies become discouraged and quit. So, thinking that spawns should have a personal count for each player (or login account) that way it will always be there for any newb whenever they start up plus anyone who restarts a new player maybe. Then camping is useless but I can see some special spawns being unlimited but maybe only spawn once per day and still other spawns having an absolute limit.
I also question whether scavenging or foraging should be a skill as they could just farm supplies and food through its use unless you make rare spawns around the world that require it. If you want to get really creative, you could create a new type of food source like soilent green. This would obviously be just a usage item later in the development of the server.
Another way around this food issue would be to just give food quality. Livestock and farming should be only available to dedicated players and advanced characters, and the food would provide higher "quality food". These foods could give you some sort of stat bonus. Lower quality foods could either give you just a hunger boost or stat loss. All foods would give hunger boost.
Adding onto that, you could have a "infection meter" that fills up after certain tasks. If you eat tainted meat, you gain 60%+ infection meter. This infection meter should decay very slowly and insert any skill or items you want to modify this.
Adding Quality to items in V1/V2 was always on my list but never happened. Well, it sort of happened with weapons and armor in that they need repairing but low "quality" never changed the effectiveness of the equipment. Would like to add it to V4. It would be like a sword going dull or a gun needing cleaning or with food, the better quality (less rotten) the more you get out of it. Quality would also affect price. And items could have over 100% and give more damage or protection, etc.
I think a lot of food growing and production/processing will go to feed the Haven Market and not just players. Actually giving players a good reason to spend the time farming (plough, plant, water, harvest, etc).