Field exercise: formulate three feeds (starter, grower, layer) with your raw materials and compare them

This lesson is part of Making feed on the farm, expert level specialisation. It opens to every registered student, from free registration. Levels 1 to 5 and the tracks remain readable by everyone.

Until now, the formulas came from the lesson. This time, they come from you: your raw materials, your prices of the month, your analysis reports, your spreadsheet. The exercise has you build three complete feeds, broiler starter, broiler grower and layer, check every nutrient, then put them side by side in a comparison table with four indicators every expert calculates: cost per 100 kg, cost per 1,000 kcal, cost per kilo of protein, and cost per bird or per month. The example is solved from start to finish in units so that you can check your method; your figures will give your results. By the end, you will have three formulas ready for the workshop, dated, and the sheet that will serve you every month.

• ✓Gather the exercise data: targets of the three phases, list of available raw materials with their contents (analyses or table) and their prices delivered to the workshop in units
• ✓Formulate in the spreadsheet a starter feed, a grower feed and a layer feed, and check every nutrient within target
• ✓Calculate and interpret the four comparison indicators (cost per 100 kg, per 1,000 kcal, per kilo of protein, per bird or per month)
• ✓Fill in the exercise sheet, test the sensitivity of the three formulas to a rise in maize, and conclude for the workshop

1. The equipment and the rules of the game
2. Step 1: the three targets, side by side
3. Step 2: the starter formula S1, solved
4. Step 3: the three formulas in a row, and the four indicators
5. Step 4: the exercise sheet to fill in
6. Step 5: sensitivity to the maize price, and the variant
7. Going further

• •Three targets side by side: starter 2,950 to 3,050 kcal, 22%, lysine ≥ 1.25, methionine ≥ 0.50, Ca 0.9 to 1.0, avail. P 0.45 to 0.50; grower 3,050 to 3,150, 20%, 1.10, 0.45, 0.85 to 0.95, 0.40 to 0.45; layer 2,750 to 2,850, 17%, 0.75 to 0.90, 0.40, Ca 3.5 to 4.2, avail. P 0.38 to 0.42; no cotton in starter or layer.
• •S1 starter (100 kg): maize 59.05; soya 30.3; fish meal 5; oil 2.5; limestone 0.9; phosphate 1.3; salt 0.25; premix 0.5; DL-methionine 0.2 → 2,983 kcal, 22.0%, lysine 1.25, methionine 0.58, Ca 0.99, avail. P 0.48, Na 0.15; 196.12 u.
• •Four indicators: cost per 100 kg (S1 196.12; G2 184.46; L1 159.57 u), per 1,000 kcal (0.66; 0.60; 0.58), per kg of protein (8.91; 9.22; 9.39), per bird or per month (1.08 per chick; 2.85 per chicken; 5.28 per hen per month); read together.
• •Sensitivity to maize + 20%: S1 + 6.0%, G2 + 6.9%, L1 + 7.5%: the layer is the first to open up to alternatives in the lean season; variant: one alternative at half limit, all columns rechecked, saving > 1 to 2% = candidate for a trial.
• •Sheet dated and filed with the formula version; a "no" box = draft; end point: one batch of each made, checked, grower retained sample analysed within tolerance.