Question

pH of good quality silage is

• A. Less than 3.0
• B. 3.8 - 4.2
• C. 5.0 - 7.0
• D. More than 7.0

Hint:

Silage Quality Standards: Good Quality Silage $\rightarrow$ pH 3.8--4.2, Bright green/yellow-green color, pleasant fruity lactic aroma, zero butyric acid.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Anaerobic ensiling biochemistry: rapid lactic acid fermentation by homofermentative lactic acid bacteria drops pH to 3.8--4.2 to preserve forage nutrients and inhibit clostridial proteolysis.
Key Formula or Approach:
\[ \text{Soluble Carbohydrates} \xrightarrow{\text{Homofermentative LAB}} \text{Lactic Acid} \implies \text{pH drops to } 3.8 - 4.2 \]

Step 2: Detailed Explanation:
Quality grading parameters of fermented forage (Silage):
1. Very Good Good Quality Silage: pH is 3.8 to 4.2, with lactic acid constituting $> 60 - 70\%$ of total organic acids, ammoniacal nitrogen $< 8 - 10\%$ of total nitrogen, and negligible butyric acid ($< 0.1\%$).
2. Fair Quality Silage: pH $4.2 - 4.8$.
3. Poor Clostridial Silage: pH $> 4.8 - 5.5$ with foul-smelling butyric acid, dark brown color, and high protein decomposition.

Step 3: Final Answer:
Hence, the pH of good quality silage is 3.8 - 4.2, corresponding to option (B).