a structure for preparing and storing haylage and protecting the haylage from the air. Airtight upright silos are the most commonly used type. Designs for six upright hay silos have been developed in the USSR.
Metal top-loading silos have a diameter of 6 m, a height of 16 m, and a volume of 400 cu m. The silo has a series of closable, airtight hatches running from top to bottom, through which feed is removed and dropped to the ground. The silo is loaded by a pneumatic system. Welded metal silos with a volume of 400 cu m are bottom-loaded through a hatch in the bottom part of the silo by means of a special rotary mechanism. Wooden silos are 7 m in diameter and 16 m high and have a hood made of a polyethylene film. Top-loading, prefabricated, reinforced-concrete silos are 6 m in diameter and 16 m high. Brick silos are 8 m in diameter and 18 m high, with a volume of 800 cu m; they are loaded from the top at any height. Top-loading silos constructed of reinforced-concrete blocks are 7.3 m in diameter and 21 m high, with a volume of 900 cu m.
The silos are erected on monolithic foundations. Airtight hatches are installed in the walls for unloading the haylage. The silos are enclosed with metal tops equipped with a service hatch, and the seams of the towers are made airtight with putty. On farms the silos are usually arranged in blocks near the feed shop. A shaft is installed along the unloading hatches on each tower for unloading the haylage onto conveyors; pneumatic pipelines and metal service ladders are mounted in line with the shaft.
Brick and concrete upright silos available on farms are used to prepare haylage. They are presealed by painting the plaster on the inside with a lacquer that seals out air, equipping the unloading ports with hermetically sealing metal hatches, and installing a plastic hood beneath the existing roof. Haylage keeps well in such silos; there is no waste, and the haylage does not heat up.
Haylage can also be stored in concrete trenches 6–8 m wide and 2.5–4 m deep. The length of the trench is calculated so that the trench can be filled with feed within a certain period of time (not more than four days). The walls of the trench are plastered and rubbed over with a cement solution to make them airproof. When trenches are built from prefabricated reinforced concrete, the gaps between blocks are filled with concrete and rubbed over with a cement solution. The walls of the trench are coated with a solution of bitumen in benzine to make them more airtight.
Similar haylage silos are used abroad.
L. I. KROPP