Question

why do younger pigs require a higher percentage of dietary protein (amino acids) compared to older pigs?
a) they have less efficient digestion and need more protein to compensate.
b) their growth rate and muscle protein synthesis are highest during early life.
c) older pigs excrete more nitrogen, so they need less protein.
d) younger pigs cannot use carbohydrates for energy.

Explanation:

Younger pigs have higher growth rates and muscle protein synthesis in early life. Protein (amino acids) is crucial for growth and muscle development. Option a is incorrect as young pigs' digestion efficiency isn't the main reason here. Option c is wrong as nitrogen excretion isn't the key factor for the protein requirement difference. Option d is false as younger pigs can use carbohydrates for energy. Option b correctly links the higher protein need to their growth and muscle - related biological processes.

Answer:

B. Their growth rate and muscle protein synthesis are highest during early life.