Feed Formulation Using Excel

Introduction

• Focus on feed formulation practice and tutorial videos.
• Discuss using software like WUFFDA or CFC 5 for feed formulation.
• Emphasize the potential of using Excel for feed formulation if specialized software is not available.
  • Example: Balancing diet using Excel for least cost feed formulation.
  • Future video: Non-linear programming models for maximum profit feed formulation.

Essential Steps

1. **Activating Solver Function in Excel:

   • Go to File > Options > Add-ins -> click Go and check Solver Add-in box.
   • Confirm activation in Data menu.

2. **Ingredients Information:

   • Need data on ingredient prices and nutrient composition.

   • Enter ingredients list, e.g., corn, wheat, soybean oil, etc.

   • Identify energy, protein feeds, and additives.

     • Energy ingredients: Corn, wheat, wheat middlings, soybean oil, canola.
     • Protein ingredients: Soybean meal, fish meal.
     • Calcium sources: Oyster shell meal, limestone.
     • Calcium & Phosphorus: Di-calcium phosphate.
     • Sodium sources: Sodium bicarbonate, salt.
     • Amino acids & Additives: Lysine, DL Methionine, Threonine, vitamins, and minerals.

3. **Formatting Ingredient Table:

   • Use Excel's format as table feature for better visual separation.

4. **Setting Constraints for Ingredients:

   • Define minimum and maximum inclusion rates (in percentage).
   • Fixed values for premixes (e.g., 0.25% for vitamins and minerals).

5. **Nutrient Requirements:

   • Specify nutrient constraints such as energy, protein, calcium, phosphorus, etc.
   • Example for broiler (Ross 308) grower phase nutrient requirements.
   • Varying minimum and maximum values based on experience.

Specifying Feed Formulation in Excel

1. **Creating Formula Sections:

   • Use SUMPRODUCT function to calculate diet specifications and nutrient concentrations:

     =SUMPRODUCT(weighting_row, inclusion_rate_row)
     

2. **Dietary Cost Calculation:

   • Calculate total cost by summarizing the product of cost and inclusion rate.

3. **Using Solver for Optimization:

   • Access Solver under Data tab.
   • Objective: Minimize dietary cost.
   • Adjust variable cells: Ingredient inclusion rates.
   • Set constraints: Inclusion rates, nutrient requirements, maintaining diet at 100%.
   • Solver method: Simplex LP for linear programming.
   • Apply multiple iterations, adjusting constraints as needed.

Important Considerations:

1. **Accuracy of Results:
   • Post-solver, verify and adjust infeasible or impractical values manually.
2. **Validation of Ingredient Constraints:
   • Example: Ensuring appropriate levels for soybean oil, soybean meal, fish meal, etc.

Practical Tips

• Format result table for print clarity.
• Example adjustments to enhance readability: Vertical alignment of final formulas, sorting.

Conclusion

• Demonstration of formulating a diet in Excel.
• Encouragement to experiment and practice with given method.
• Invitation to ask questions and look forward to future episodes.

Note

Future episodes to cover:

• Non-linear programming models.
• Use of digestible amino acids, especially with by-products in animal diets.

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Feel free to comment with any questions!