Final answer:
Using the Pearson square method, to achieve 15% CP on an as-fed basis for a supplement for growing beef calves, one should mix approximately 87.3% corn gluten meal and 12.7% beet pulp.
Step-by-step explanation:
To formulate a supplement for growing beef calves that contains 15% CP on an as-fed basis using the Pearson square method, we will consider the crude protein (CP) percentages of beet pulp and corn gluten meal on a dry matter (DM) basis and include the dry matter content in our calculations.
The beet pulp has 9% CP [DM] and the corn gluten meal has 68.2% CP [DM]. The desired CP percentage is 15%, which we need to adjust for the DM content of the feed ingredients before using the Pearson square.
Therefore, the adjusted CP for beet pulp is 9% × 91% DM = 8.19% CP (as-fed basis), and for corn gluten meal it's 68.2% × 90% DM = 61.38% CP (as-fed basis).
To use the Pearson square, follow these steps:
- Place the desired percentage of CP in the middle of the square (15%).
- Place the adjusted as-fed CP percentages of beet pulp (8.19%) and corn gluten meal (61.38%) at the left corners of the square.
- Calculate the difference between each corner and the center value, and place these values at the right corners of the square.
- The difference for beet pulp is 15% - 8.19% = 6.81%, and for corn gluten meal it's 61.38% - 15% = 46.38%.
- The ratios for the two ingredients are then found by taking the value across from one ingredient and dividing by the total of the two values: Beet pulp ratio is 46.38 / (6.81 + 46.38) and corn gluten meal ratio is 6.81 / (6.81 + 46.38).
- These ratios give us the amounts of each ingredient to achieve the desired CP percentage. The final mixture should contain approximately 87.3% corn gluten meal and 12.7% beet pulp (as-fed basis).
This formulation will provide the required 15% CP for the growing beef calves.