The nutrient content of the diets was calculated according to the chemical
composition of raw feedstuffs, metabolizable energy value, according to equations
from European Tables (1989). The chemical composition of DDGS and other
feed components was determined by conventional methods (AOAC, 1990).
Amino acids were analysed in acid hydrolysates, sulphur amino acids, after initial
peroxidation in the colour reaction with the ninhydrin reagent using a BeckmanSystem
Gold 126 AA automatic analyser. The calcium content was determined
by flame atomic absorption spectrophotometry, while phosphorus content, by a
calorimetric method (AOAC, 1990).