Here's an extra-large chicken coop.
Shop category: Chicken Enclosures
Animals: 1000 chickens
Purchase price: $310,000
Feed capacity: 100,000
Straw capacity: 45,000 (Rapeseed straw is also accepted if it's included in your map)
Take good care of the animals, and you'll get plenty of eggs and manure to fertilize your fields.
Daily upkeep costs: $130
A visually customized manure heap is also available in the "Silos" category.