Dairy cow feeding : comparison of energy feeding systems

Abstract

Energy requirements (for maintenance, lactation and body weight changes), of dairy cows yielding 20 to 45 kg milk day, as well as energy value of feeds (metabolizable energy content ME, efficiency of ME utilisation, kl, net energy content given by the American (NRC), British (ARC), Dutch (VEM), French (UFL) and German (NEL) systems were compared. The corrections used in each system for associative effects between feeds were taken into account. The validity (accuracy) of the Dutch and French systems was checked using indirect calorimetry balances and feeding trials, and that of the British system using feeding trials. The quantities of feeds required to meet the energy requirements of lactating cows were similar in the Dutch and French systems. The differences between these systems and the three others were larger and increased with milk yield, especially in the American (NRC) and German (NEL) systems.