Answer :
Final answer:
The %N * 6.25 formula is used to estimate crude protein content based on nitrogen analysis and the Kjeldahl method. The factor 6.25 converts nitrogen percentage to crude protein, assuming proteins are approximately 16% nitrogen.
Explanation:
This estimation is based on the Kjeldahl method, a chemical procedure developed by Johan Kjeldahl. The factor 6.25 derives from the average nitrogen content in proteins, which is approximately 16%. Given a certain percentage of nitrogen (%N) determined through analysis, multiplying this value by 6.25 gives the corresponding crude protein percentage.
To find the crude protein in a given sample, as in the example provided, a nitrogen content of 7.0g is multiplied by 6.25, resulting in a crude protein content of 43.75g. This is essential for understanding the nutritional value of feeds and fertilizers and ensuring proper dietary requirements are met.
Examples
- If a nitrogen analysis indicates 7.0g of nitrogen, the crude protein content would be calculated as 7.0 x 6.25, equal to 43.75g of crude protein.
- In a fertiliser sample, if 40% by weight is nutrient, a 500g sample would contain 200g of nutrients as seen in the calculation 0.4 x 500g.
