Rate and extent of losses from top spoilage
in alfalfa silages stored in bunker silos

Alfalfa silages were made in pilot- and farm-scale silos, and five sealing treatments were compared. After 90 days, sealing dramatically reduced DM losses at the 5 and 10 in. depths in the farm silos and at the 0 to 12, 12 to 24, and 24 to 36 in. depths in the pilot silos. Extending the storage period to 180 days in pilot silos had no effect on DM losses for sealed or delay sealed silages, but DM losses for unsealed silages continued to increase at all three depths. Placing a roof over the unsealed, farm-scale silo increased the silage DM content at all three depths, increased storage temperatures at the 10 and 20 in. depths, and reduced DM loss at the 10 in. depth compared to the unsealed silo without a roof. Rainfall was much above normal (16.8 in. during the first 90 days of storage; 11.2 in. the second 90 days) and contributed to huge increases in the moisture content of silage at the lower depths in the unsealed, no roof, pilot- and farm-scale silos.