This is how Indie Stone fixed the Chicken Apocalypse problem.   [Presented without comment.]     Can you upload a console file with these issue from an unmodded game?  

Thanks for the suggestion. I agree that excessive numbers of items can contribute to memory usage and potentially to OutOfMemory crashes. However, I do not believe this fully explains what I am seeing in this save. In my case there are very few items actually lying on the ground. Most loot is stored normally inside bookshelves, crates, containers, and other storage objects. I do not have massive piles of loose items covering the map. More importantly, the save is exhibiting several animal-related issues that seem unrelated to simple item count: Real chicken duplication (not just UI duplication). Duplicated chickens with identical names/IDs. Both chicks and hens affected. Incorrect animal counts inside animal zones. Chickens appearing to be overwritten/renamed into duplicates. Extremely rapid hutch dirt accumulation (from freshly cleaned to 74% dirt within only a few in-game hours). Mass chicken deaths inside the affected hutch. Periodic stutters every 4–6 seconds that appear around the same time these animal issues occur. I have also observed that when the animals are alive and behaving normally, the periodic stutters seem to be absent or significantly reduced. Additionally, the issue persists across new characters created in the same world, which suggests the problem may be tied to world data rather than a specific character. So while memory usage from stored items may certainly be a contributing factor, I am not convinced it explains the animal duplication, incorrect animal data, hutch corruption, rapid dirt accumulation, mass deaths, and periodic stutters that are all occurring in the same save. If needed, I can provide console logs and further details about the affected animal zones.

Sure. However, it does not make sense and seems to be a bug. And that is the reason why we report it here. Pigs seem to be different than other animals (regarding poop). Or to put it more formally: "Some animals are more equal than others". Who knew that TIS implemented this as well. 

Can you try disabling it briefly while playing to see if it helps at all?

I assume if you play with the sandbox you can add the dung items to the list of items that despawn from the ground.