Which feed component is essential for muscle development in livestock?

Protein is essential for muscle development in livestock because it is the primary building block necessary for the growth and repair of tissues, including muscle tissues. Proteins are made up of amino acids, which are crucial for various bodily functions, including muscle synthesis. When livestock consume protein, their bodies break it down into amino acids and then use these amino acids to build and repair muscle fibers, making protein vital for healthy muscle growth and overall body condition.

Fats and carbohydrates also play important roles in livestock nutrition, but they primarily serve as energy sources rather than direct contributors to muscle development. Fats provide a concentrated energy source, while carbohydrates are crucial for energy but do not directly aid in building muscle tissue. Vitamins are essential for various metabolic processes and overall health but do not directly contribute to muscle development. Therefore, protein is the correct answer as it directly supports the growth and maintenance of muscle mass in livestock.