Worksheet Nutrition What two classes make up the composition of feeds? Concentrates and roughages Which of the two classes would include corn, wheat, oats, and soybean meal? Concentrates What do roughages consist of? Hays and straws, silages, cut green feeds, and grazed forages. Concentrates are high in energy, low in fiber, and highly digestible. What are the six basic classes of nutrients? Water, carbohydrates, fats, protein, minerals, and vitamins Water is the most important nutrient. Water helps to transport other nutrients. Carbohydrates are a major energy source. The primary energy source is fat, with 2.25 times more energy per pound than any other source. Proteins are the only nutrient class that contain nitrogen. Proteins make amino acids, which are the building blocks of the body. Elements other than carbon, hydrogen, oxygen, and nitrogen are minerals. There are 16 known vitamins in animal nutrition. Nutrients that supply energy to the animal are carbohydrates, fats, and proteins. Energy is important for healthy animals because two functions run by energy are body maintenance and reproduction. Nutrients are any feed component that function in the support of life. Fill in the blank Water is the most important nutrient. Water helps to transport other nutrients. Carbohydrates are a major energy source. The primary energy source is fat, with 2.25 times more energy per pound than any other source.