Prediction of Available Energy in Dairy Cow Rations from Dietary Fiber

Abstract

Two published equations and four derived equations that predict dietary energy from dietary crude or acid detergent fiber were evaluated for accuracy. The equations estimated total digestible nutrients, digestible energy, metabolizable energy or net energy lactation of diets of cows completing 480 lactations in which mean dietary crude fiber varied among seven dietary groups from 17 4 to 225 g crude fiber per kilogram of dry matter consumed. Intakes of available dietary energy were compared against feeding standard requirements. Mean quotients obtained by dividing energy intakes from equations by energy requirements (concurrence values) varied from 1.00 to 1.05 among equations. Concurrence values decreased as dietary fiber increased. Available dietary energy content expressed in any common energy term was accurately predicted from dietary fiber for full-fed milking Holsteins through use of equations presented in the text.