The amount of protein b. The quality or kind of protein 2. Once an animal has consumed the needed amount of protein for cell construction, muscle, fetal growth, etc., the rest is broken all the way down for use as body energy.
Carbohydrate is usually a much less expensive source of energy.
There are ten essential amino acids. Certain amino acids necessary for growth are not essential for merely maintaining an animal. All ten essential amino acids can be made in ruminants by the rumen bacteria from simple forms of nitrogen in the feed. Therefore, the bacterial protein may provide all of the essential amino acids, even though they are lacking in the feed which the ruminant eats. Show pictures of protein-deficient animals to the students.