Question

The dry matter requirement of a cow weighing 600 kg would be

• A. 10 kg
• B. 15 kg
• C. 20 kg
• D. 25 kg

Hint:

To quickly estimate dairy cattle dry matter requirements, use the standard factor:
\[ \text{Daily DMI} = 2.5\% \text{ of Body Weight} \] For a \(600 \text{ kg}\) cow: \(600 \times 0.025 = 15 \text{ kg}\). This simple calculation is highly useful for feed formulation.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
To formulate accurate balanced rations for dairy cattle, we must first estimate their daily dry matter intake (DMI) capacity. Daily DMI is determined primarily by the animal's body weight and level of milk production.

Step 2: Detailed Explanation:
Let us calculate the daily dry matter requirement for a standard dairy cow:

According to standard animal nutrition guidelines (such as ICAR or NRC standards), an adult dairy cow requires dry matter (DM) equivalent to approximately2.0% to 2.5% of her body weight daily for maintenance and moderate milk production.

For a cow weighing \(600 \text{ kg}\): \[ \text{Minimum DMI} = 600 \text{ kg} \times 2\% = 12 \text{ kg} \] \[ \text{Standard DMI} = 600 \text{ kg} \times 2.5\% = 15 \text{ kg} \]
High-yielding dairy cows can consume up to 3% to 3.5% of their body weight in dry matter (up to 18-21 kg for a 600 kg cow), but the baseline daily dry matter requirement for a standard 600 kg cow is established as15 kg.

An intake of 10 kg (under 1.7% of body weight) is too low for maintenance, while 20 kg and 25 kg represent the extreme physiological limit for very high-yielding cows rather than the standard average requirement.
Therefore, 15 kg is the appropriate target dry matter requirement.

Step 3: Final Answer:
The correct option is (B), representing 15 kg.