Energy and Fiber in Dairy Cow Rations and Utilization by the Modern High-Producing Cow

Abstract

Of the five major classes of nutrients (energy, protein. minerals. vitamins, and water) needed by the dairy cow, the nutrient most often limiting milk production is energy. A simple definition of energy is "the ability to do work." The basic energy unit is the calorie. A calorie is the amount of heat required to raise the temperature of one gram of water one degree centigrade. A gram of water is the amount contained in one milliliter, or one cubic centimeter (cc). A centigrade degree is 1.8 times as large as a Fahrenheit degree, which is more commonly used in the United States. The relationship of the calorie to other energy terms is shown in Table 1.