Concept:When feed is given only to keep an animal’s body weight unchanged, it is called a maintenance ration.
Explanation:Animals need nutrients for two main purposes: maintenance and production.
Maintenance means keeping the body alive, warm, and at a constant weight.
It does not support extra growth, milk, eggs, or work.
Such a ration supplies just enough energy and protein to balance daily losses.
If more than maintenance is given, the extra nutrients become production.
Therefore, feed provided only to sustain live weight is known as a maintenance ration.
Answer:B. maintenance ration