4. 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.

5. 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.

6. 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.

7. 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.

8. Notice Alfalfa

9. 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.

10. Preparing the Active Ingredient Matrix
Copying data from the Ingredient Composition Storage Matrix to the Active Matrix:

11. Click on the “38” to highlight the Canola line, then press the right mouse button to pull down the edit menu, and click “Copy”.

12. Press the <Page Up> key or scroll up to see the Active Ingredient Composition Matrix

13. Click on the “15” to highlight the Alfalfa line, then press the right mouse button to pull down the edit menu, and click “Paste”.

14. Alfalfa Data Replaced by Canola Data

15. 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.

17. Highlight the data to be copied by holding down the left mouse button while dragging the mouse across the block.

18. Press the right mouse button and click on “Copy”.

19. 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.

20. And the Broiler Grower Feed becomes the “Current Specification”.

21. By Copying and Pasting, the Original Data Remains Unchanged
By Copying and Pasting, the Original Data Remains Unchanged. A New Nutrient Specification Can Always Be Copied and Stored for Future Use.

22. Ratios Between Nutrients
It is easy to specify ratios between nutrient minimum requirements in WUFFDA.
Simply insert a formula in the cell containing the requirement.
In the following example, the available phosphorus requirement in cell C14 is set equal to ~38.9 % of the calcium requirement in cell C12.

24. Ratios Between Nutrients
To assure that exact ratios will be achieved in the solutions is a more complex problem.
Another column or “nutrient” must be added to the ingredient matrix.
This causes the ratio information to be stored with the ingredient composition matrix and not with the nutritional requirements.

25. Ratios Between Nutrients
The new column is calculated by:
C=A-(P x B)
Where:
C = Coefficient
A = Value of First Nutrient
B = Value of Second Nutrient
P = Desired Proportion Between Nutrients

26. A new column to set the Calcium to Phosphorous Ratio equal to 2
A new column to set the Calcium to Phosphorous Ratio equal to is created by inserting an equation in the new column:

27. When the equation is copied to all the cells in the column, values for ingredients with higher Ca:P ratios are more positive :

28. The Value for the Ca:P ratio should be fixed at zero, so the positive and negative coefficients balance each other out.

29. The Available Phosphorous in the solution is exactly half the Calcium level when the Ca:P=2 coefficients total to zero.

30. If only the minimum requirement for Calcium is changed, the amounts of Calcium and Available Phosphorous in the solution changes.

31. 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:

33. 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.

34. 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.

35. Or You Can Get Excel to Formulate the Least-Cost Feed By Choosing “Solver…” From the Tools Menu.

36. Constraints have all been set in the Solver Dialogue Box, so just click on the “Solve” Button.

37. Hopefully Solver will find a solution and you can just click on the “OK” Button to see what it is.

38. The Amount of Each Ingredient in the Formula and the Nutrients the Diet Supplies Will Be Displayed.

39. 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.

40. “Print Preview” of a Feed Specification.

41. Output From Formulations
Results are also graphed on the “Graph” spreadsheet for viewing in another perspective: as a proportion of the minimum requirement.

42. Scroll to See Both Graphs

43. 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).

45. 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.

46. Sensitivity Analyses
Choose “Sensitivity” from the list of possible Reports in the Solver Results Dialogue Box.

47. 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.

48. This feed should contain % Corn unless the price increases by $0.989, or decreases by $ Corn’s current value is $5.25 per 100 pounds.

49. This formulation would begin to use barley if it’s price decreases by $2.0989.

50. The cost of the feed is expected to change by $0
The cost of the feed is expected to change by $ if the level of protein specified were to change by 1 unit up or down.

51. 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.

52. Good Luck
WUFFDA