Question

Which milk constituent is less in colostrum as compared to normal milk?

• A. Whey proteins
• B. Fat
• C. \(\beta\)-carotene
• D. Lactose

Hint:

Colostrum vs Normal Milk Composition:
Higher in Colostrum = Immunoglobulins (IgG), Total Protein, Ash, $\beta$-Carotene, Fat.
LOWER in Colostrum = LACTOSE (2.7% vs 4.8%).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Comparative compositional biochemistry of bovine colostrum vs mature normal milk: colostrum contains vastly elevated immunoglobulins ($6-15\%$), total solids ($24\%$), minerals, and $eta$-carotene, but is markedly lower in lactose ($2.5-3.0\%$ in colostrum vs $4.8\%$ in mature milk).
Key Formula or Approach:
\[ \text{Composition Comparison: } \text{Lactose in Colostrum } (\mathbf{2.5 - 3.0\%}) \quad \ll \quad \text{Lactose in Normal Milk } (\mathbf{4.7 - 4.9\%}) \]

Step 2: Detailed Explanation:
Comparison between Bovine First-Milking Colostrum and Mature Normal Milk:
1. Higher in Colostrum:
- Total Proteins Whey Proteins: $14 - 18\%$ in colostrum (dominated by Immunoglobulins IgG1, $6 - 10\%$) vs $3.2 - 3.4\%$ in normal milk.
- Total Solids: $24 - 27\%$ vs $12.5\%$.
- Minerals Ash: $1.0 - 1.2\%$ vs $0.7\%$.
- $\beta$-Carotene & Vitamin A: $10\times$ higher.
2. Less (Lower) in Colostrum:
- Lactose (D): Only 2.5% to 3.0% in colostrum, compared to 4.7% to 4.9% in normal mature milk. Lower lactose protects the neonatal gut from osmotic secretory diarrhea during early suckling.

Step 3: Final Answer:
Therefore, Lactose is less in colostrum as compared to normal milk, matching option (D).