Question

What is a direct measure of the proportion of the dietary protein that can be utilised by the animal for synthesising body tissues and compounds?

• A. Ideal protein value
• B. Biological value
• C. Digestible crude protein value
• D. Protein efficiency ratio

Hint:

Biological Value (BV) focuses specifically on the utilization of absorbed nitrogen.
This makes it a precise measure of protein quality and amino acid balance.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The nutritional quality of dietary protein depends on its amino acid profile and digestibility.
Several bioassays and indices are used to measure how efficiently an animal utilizes absorbed dietary nitrogen for maintenance and growth.

Step 2: Detailed Explanation:
Let us review the common measures of protein quality:
- Biological Value (BV): This index directly measures the proportion of absorbed dietary nitrogen that is retained by the body.
It accounts for nitrogen lost in feces and urine, reflecting how well the amino acid profile of the food matches the animal's needs:
\[ \text{BV \%} = \frac{\text{Nitrogen Retained}}{\text{Nitrogen Absorbed}} \times 100 \]
- {Protein Efficiency Ratio (PER): Measures weight gain per gram of crude protein consumed, but does not directly measure nitrogen retention.
- {Digestible Crude Protein (DCP): Represents the portion of crude protein that is digested and absorbed, but does not measure how well that absorbed nitrogen is utilized inside the body.
- {Ideal Protein Value: A theoretical model of the optimal pattern of amino acids required by the animal, rather than a direct measurement.
Therefore, Biological Value is the direct measure of the proportion of absorbed protein utilized by the animal for tissue synthesis.

Step 3: Final Answer:
The direct measure of the proportion of absorbed protein utilized by the animal for synthesis is the Biological Value.