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WUFFDA Basics. WUFFDA requires the MicroSoft Excel spreadsheet program with the Solver Option installed. Basic knowledge of spreadsheet usage is all that is required to use the program. WUFFDA can solve a problem with 25 ingredients and 34 nutrients. First Step in the Formulation Process.
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WUFFDA Basics • WUFFDA requires the MicroSoft Excel spreadsheet program with the Solver Option installed. • Basic knowledge of spreadsheet usage is all that is required to use the program. • WUFFDA can solve a problem with 25 ingredients and 34 nutrients.
First Step in the Formulation Process • Prepare an ingredient composition matrix. • WUFFDA contains nutrient composition data for a large number of ingredients. • You may enter data directly into the “Active” Ingredient Matrix • Or you may copy data from the “Storage” matrix to the Active matrix.
Ingredients • The Active Ingredient Composition Matrix Box is at the top of the “Ingredients” spreadsheet. • Ingredient composition information is stored at the bottom of the “Ingredients” spreadsheet. • The composition of any number of ingredients may be stored there.
Active Ingredients • The ingredients in the Active Ingredient Composition Matrix Box will be used in the current formulation. • The next window shows a typical ingredient composition matrix for a broiler diet.
Preparing the Active Ingredient Matrix • Copy ingredient composition data from the storage area at the bottom of the spreadsheet to the active matrix area at the top • Always make any changes that you want to be permanent at the bottom of the sheet and copy them to the top.
Preparing the Active Ingredient Matrix • Copying data from the Ingredient Composition Storage Matrix to the Active Matrix:
Click on the “38” to highlight the Canola line, then press the right mouse button to pull down the edit menu, and click “Copy”.
Press the <Page Up> key or scroll up to see the Active Ingredient Composition Matrix
Click on the “15” to highlight the Alfalfa line, then press the right mouse button to pull down the edit menu, and click “Paste”.
Nutrient Requirements • Next, the nutritional requirements must be set: • Lists of nutritional requirements are contained on the “Nutrients” spreadsheet. • You can enter data directly into the “Current Specification” Area. • Or you may Cut and Paste from stored requirement lists.
Highlight the data to be copied by holding down the left mouse button while dragging the mouse across the block.
Place the cursor on cell C4 at the upper left corner of the Current Specification Box and choose “Paste” from the pull-down edit menu.
And the Broiler Grower Feed becomes the “Current Specification”.
By Copying and Pasting, the Original Data Remains Unchanged. A New Nutrient Specification Can Always Be Copied and Stored for Future Use.
Formulating A Diet • When the ingredients have been chosen and the nutrient limits have been set, it is time to formulate the diet. • Go to the “Formulate” Spreadsheet:
Formulating a Feed • The Formulate Spreadsheet contains the same minimum and maximum requirement data as the Ingredient and Nutrient Spreadsheets. • Changes to requirement data should only be made on the Ingredients and Nutrient Spreadsheets.
Formulating a Feed • You can enter data directly into the “Amounts” column on the left of the spreadsheet, and the nutrients supplied by those amounts will be displayed on the right in the “Supplied” column. • This is an excellent method of estimating what is in a feed that is already formulated.
Or You Can Get Excel to Formulate the Least-Cost Feed By Choosing “Solver…” From the Tools Menu.
Constraints have all been set in the Solver Dialogue Box, so just click on the “Solve” Button.
Hopefully Solver will find a solution and you can just click on the “OK” Button to see what it is.
The Amount of Each Ingredient in the Formula and the Nutrients the Diet Supplies Will Be Displayed.
Output From Formulations • The information from the Formulate Spreadsheet is Automatically transferred to the Feed Spec. Spreadsheet for printing on a black & white printer, on a single sheet of paper.
Output From Formulations • Results are also graphed on the “Graph” spreadsheet for viewing in another perspective: as a proportion of the minimum requirement.
Output From Formulations • A mixing sheet can also be printed from the “Mixing Sheet” Spreadsheet. • The <Ctrl> and <m> keys must be pressed together to sort the data from the largest ingredient to the smallest (the order they should be added to the mixer).
Sensitivity Analyses • Solver can give information on how feeds may change: • Changes in ingredient usage when ingredient prices change. • Changes in feed prices when nutrient levels change.
Sensitivity Analyses Choose “Sensitivity” from the list of possible Reports in the Solver Results Dialogue Box.
Sensitivity Analyses • This creates the Sensitivity Report Spreadsheet, containing all the necessary information. • Each time the feed is formulated an additional Sensitivity Report is created if requested. It may be best to delete them as soon as they are no longer needed.
This feed should contain 52.09 % Corn unless the price increases by $0.989, or decreases by $0.129. Corn’s current value is $5.25 per 100 pounds.
This formulation would begin to use barley if it’s price decreases by $2.0989.
The cost of the feed is expected to change by $0.4201 if the level of protein specified were to change by 1 unit up or down.
Time to Give WUFFDA a Try • If you don’t get a feasible solution: • Relax constraints one at a time until you get a feasible solution. This should help identify the problem. • Make sure you use the same units throughout the problem. • Make sure there is Methionine Plus Cystine activity in the DL-Methionine, etc.
