Apparent digestibility of selected marine and terrestrial feed ingredients for tropical spiny lobster Panulirus ornatus

This study reports the dry matter (DM), organic matter (OM), crude protein (CP), total lipid (TL) and gross energy (GE) apparent digestibilities of five marine animal and three terrestrial plant feed ingredients using sub-adult tropical spiny lobster (Panulirus ornatus) of 600–800 g. Apparent digestibility was determined using standard substitution procedures and employing ytterbium as the digestibility marker. Test ingredients were used at a substitution rate of 500 g kg− 1 or 300 g kg− 1 for animal or plant ingredients, respectively. In each of the two digestibility experiments (n = 5, the reference and four substituted diets were fed to lobsters fitted with a balloon fecal collection device. This enabled the collection of voided feces without contact with seawater and subsequent leaching losses. The derived DM, OM, CP, TL and E apparent digestibilities respectively were: 76, 81, 89, 64 and 83% for New Zealand mussel meal; 67, 79, 84, 77 and 81% for Peruvian fish meal; 69, 77, 89, 66 and 78% for spray-dried Antarctic krill meal; 53, 65, 85, 53 and 72% for Chilean langoustine meal; 47, 48, 59 41 and 58% for Japanese squid meal; 71, 66, 81, 41 and 72% for Australian solvent-extracted soybean meal; and 51, 57, 86, 33 and 63% for Australian dehulled lupin kernel meal (cv Wonga). The DM, OM, CP and E apparent digestibility of wheat flour were 82, 69, 74 and 72% respectively.