Metabolisable energy and amino acid digestibility of high-oil maize, low-phytate maize and low-phytate soybean meal for White Pekin ducks

Abstract

1. Two experiments were conducted to determine the metabolisable energy and amino acid digestibilities of high-oil maize (HOM), low-phytate maize (LPM) and low-phytate soybean meal (LPSBM) as compared with normal maize (NM) and normal soybean meal (NSBM) using male White Pekin ducks. 2. In the first experiment, the TMEN (kJ/g) value of HOM (16·58) was higher than that of NM (16·05), but that of LPM (16·11) did not differ from those of HOM or NM. The true digestibility coefficients for methionine (0·874, 0·871 or 0·876), lysine (0·805, 0·816 or 0·813) and tryptophan (0·946, 0·959 or 0·960) did not differ among NM, LPM and HOM, respectively. The average true digestibility coefficients for all amino acids in NM, LPM or HOM (0·886, 0·890 or 0·900, respectively) did not differ among the three ingredients. 3. In the second experiment, the TMEN value of LPSBM (12·39) was approximately 8% higher than that of NSBM (11·46). The true digestibility coefficients for most amino acids were higher for LPSBM than for NSBM, except in the case of histidine, cysteine and tyrosine, which were not different. The average true digestibility coefficient for all amino acids in LPSBM (0·945) was higher than in NSBM (0·924). 4. Results of the two experiments indicate that the energy and amino acids in the feed ingredients evaluated were well utilised by ducks and that LPSBM has a higher energy value as well as digestible essential amino acid concentration than NSBM for ducks.