An economic impact decision support tool for farm specific estimation of not covering horizontal silos storing corn silage
In a horizontal silo (i.e. bunkers and trenches), considerable silage is exposed to environmental elements and, if left uncovered, results in significant feed shrink and economic loss. Depending on the silo dimensions and silage density, 25% of the total volume of corn silage may be within the top 1 m of silage. The objective of this project was to create a producer-friendly dashboard tool (SAP America, Inc. Newtown Square, PA) to highlight the cost of not covering a horizontal silo storing corn silage. Farm-specific inputs of the dashboard tool are adjustable by the end user and include silo dimensions, dry matter of the silage, price of shelled corn/bushel, and total cost to cover silage including price of cover and labor. Bunker silage volume was calculated using silo dimensions including: (1) wall height (height of the silage next to the wall), (2) mean width (width of the silo measured half way up the silo), (3) filling ramp length (length of front filling ramp measured horizontally), (4) dome height (height of the silage above the top of the wall), (5) back ramp length (length of the back silage ramp measured horizontally), and (6) wall length (wall length at the top of the silo). Bunker silage volume calculations were generated from Brian Holmes’s Investment and Annual Costs of Forage Storage Calculator (www.uwex.edu/ces/crops/uwforage/bunkersilovolume10-18-08.xls) from the University of Wisconsin-Madison. The dashboard tool outputs lost revenues from not covering a silo. This was calculated by silage price per ton (price of shelled corn/bushel × 8), multiplied by dry matter lost, and subtracting the cost of covering silage. To demonstrate model utility, total bunker silage amount was set at 1494 metric tons, dry matter density was 6.35 kg/m3, price of corn was $5.00/bushel, total price of plastic was $485/horizontal silo, and total labor cost was $100 for covering the silo. With these inputs, the total lost revenues from not covering the silo was $1,100/year. Dairy producers may use this model as a decision support tool to highlight lost revenue from not covering silos.
Keywords: silage covering, economic dashboard, extension tool