Stores grain/corn/teff grass as fodder for your farm animals, increasing the farm's productivity.
Silo is an Agricultural Improvement module for animal farms, which improves the efficiency of animal farms when provided with certain resources specific to the region: 
Grain in the Old World, 
Corn in the New World, 
Teff in Enbesa. It consumes 1 ton of appropriate resource every 5 minutes (0.2 tons per minute), so by default one grain/corn/teff farm can support up to 5 silos. When operational, a silo increases the productivity of its animal farm by +100% and also makes it provide extra ton of the product every 3rd cycle. Effectively, with no other bonuses being active, a farm with a silo has its output increased to 266%.
Silo requires 
Bright Harvest DLC and can be built in the Old World (and Cape Trelawney), the New World and Enbesa. It has to be built within the radius of the farm building and it needs its own road connection to the 
Warehouse or appropriate crop farm. Each animal farm can have only one silo.
