Submitted to: Forages for Ruminants Conference Proceedings Quality
Publication Type: Proceedings
Publication Acceptance Date: September 27, 1994
Publication Date: N/A
Technical Abstract: Silo selection is an important consideration in designing a silage system. Costs, labor requirements, energy requirements and losses are all influenced by the type of structure used. These factors are interrelated, making it difficult to determine the best option. Proper comparison of silage systems requires a comprehensive analysis of all factors from harvest to feeding. A computer model called DAFOSYM provides such an analysis. DAFOSYM simulates the growth, harvest storage, feeding and use of alfalfa and corn on dairy farms. DAFOSYM was used to compare the performance and economics of bunker, stave and sealed tower silage systems on representative Ontario dairy farms. The simulation results imply that there are only small differences between silage systems which use either well managed top-unloaded, stave silos or bunker silos. Bunker silos may cost a little more than stave silos, and their use normally results in a little greater storage loss of dry matter and nutrients. On a smaller farm, the stave silo system provided a little greater net return to the farm. On a larger farm where a large bunker was used in place of two or more smaller tower stave silos, the total system costs and net returns were similar. Bottom unloaded sealed silos were least economical. The structure and unloader were more costly than that used for other types and the required lower harvest moisture content caused greater harvest losses. When a cover was not used on bunker silos, stave silo systems became the most economical option. The use of a plastic cover on a bunker silo returned $8 for each additional dollar spent on plastic and the labor required to handle the plastic.