Which of the following is a major source of protein for livestock?

• A. Barley
• B. Grass
• C. Soybeans
• D. Corn

Answer: (C)

Soybeans are recognized as a major source of protein for livestock due to their high protein content, typically ranging around 40% to 50% on a dry matter basis. They are commonly processed into soybean meal, which is used extensively in animal feed formulations. This makes soybeans particularly valuable in the nutrition of livestock, as they not only provide essential amino acids necessary for growth, reproduction, and overall health, but they also serve as a cost-effective feed option for producers.

In comparison, while barley, grass, and corn are important components of livestock diets, they offer lower protein levels. Barley is primarily a source of energy with moderate protein content, grass provides essential fiber but varies widely in protein levels based on type and maturity, and corn is also primarily an energy source with relatively low protein content. Thus, when it comes to protein density and nutritional value for livestock feeds, soybeans stand out as the preferred choice.