The yields of metabolizable energy for ducks and protein, so as the multiplication effect by different varieties of maize have been investigated. For the conditions in the Plovdiv region the hybrid PR35P12 had the highest yield of crude protein - 1368 kg/ha, and metabolizable energy – AME- 171,5 GJ/ha and TME – 181,3 GJ/ha. The highest multiplication effect (protein yield/crude protein applied by seed material) – showed hybrid PR35P12 - +403.3.
