Ž . Aquaculture 184 2000 115–132 www.elsevier.nlrlocateraqua-online Digestibility of macronutrients, energy and amino acids, absorption of elements and absence of intestinal enteritis in Atlantic salmon, Salmo salar, fed diets with wheat gluten T. Storebakken a,) , K.D. Shearer b , G. Baeverfjord a , c ˚ a b d B.G. Nielsen , T. Asgard, T. Scott, A. De Laporte ˚ a ( ) AKVAFORSK Institute of Aquaculture Research A.S. , Sunndalsøra N-6600, Norway b Northwest Fisheries Science Center, NOAAr NMFS, 2725 Montlake BouleÕard E., Seattle, WA 98112, USA c BioMar, Myre N-8430, Norway d Amycor, Amylum Group, Burchstraat 10, Aalst B-9300, Belgium Accepted 3 September 1999 Abstract Ž . Apparent digestibility coefficients ADCs of macronutrients and energy, and apparent absorp- Ž . tion coefficients AACs of amino acids and elements were assessed in an experiment with 0.9 kg Atlantic salmon reared in saltwater tanks. Duplicate groups of fish were fed five diets, where 0, Ž . Ž . 6.25,12.5,25 and 50% of crude protein CP from fish mealFM was replaced with CP from Ž . wheat gluten WG . In Experiment 2, triplicate groups of 0.9 kg salmon were fed a FM diet, a diet Ž . with 15% of CP from FM replaced with extracted, toasted soybean meal SBM ,and a diet with 35% of CP from WG, for 18 weeks. Experiment 2 was designed to determine whether WG caused pathological changes in the intestinal epithelium, and if a diet with 35% of CP from WG could support rapid growth. There was a trend toward increased ADC of fat and energy in the diets with WG, and the diet with 25% WG was ranked significantly higher than the FM control. The ADC of CP and AACs of all amino acids except alanine and lysine increased significantly with increasing proportion of dietary protein from WG, and the results indicate that absorption of individual amino acids from WG was between 94% and 100%. WG is low in lysine, but the results indicate that the requirement for lysine was nearly met and the requirement for other essential amino acids was met even with the highest WG inclusion level, due to high dietary protein concentration and the supplementary amino acid profile of FM. There was no reduced absorption of Ca, P or Mg in the ) Corresponding author. Tel.: q47-71-69-53-14; fax: q47-71-69-53-01; e-mail: trond.storebakken@akvaforsk.nlh.no 0044-8486r00r$ - see front matter q 2000 Elsevier Science B.V. All rights reserved. Ž . PII: S 0 0 4 4 - 8 4 8 6 9 9 0 0 3 1 6 - 6