Appendix B: Animal nutrition
Several systems have been devised which make it possible to express the nutritional requirements of work animals and formulate diets based on corresponding nutrient and energy values of feeds. A simple and practical method used in many parts of Africa is based on a standard called the forage unit. A forage unit is defined as the net energy value of one kilogram of barley. It is the energy contained in the proteins, carbohydrates (starches), and fats which compose the barley and which the animal does not lose through elimination of feces, urine or gas, or in heat (work) produced by digestive organs. Net energy is defined as the energy available for maintenance of body functions-heartbeat, respiration, heat, motion. Energy intake above maintenance level is stored as fat or used for production or work. The abbreviation U.F. (Unite Fourragère) designates one (1) forage unit.