Pfeffer E ; Kinzinger S ; Rodehutscord M ;

Aquaculture Nutrition vol. 1 (2)   pp. 111-117, 1995

Inst. Tierernaehrung, Endenicher Allee 15, D-53115 Bonn, FRG

Apparent digestibilities (D) of energy and proximate nutrients were determined in rainbow trout, Oncorhynchus mykiss (Walbaum), by stripping faeces and using Cr sub(2)O sub(3) as a marker. When wheat gluten + L-lysine HCl (WG-lys) as sole source of dietary N were increased stepwise from 324 to 941 g kg super(-1), replacing 210 g kg super(-1) fish oil (FO) and 407 g kg super(-1) gelatinized corn starch (GCS), D of crude protein rose from 96 to 99% and that of FO was always above 96%. D of GCS was 70% at inclusions up to 210 g kg super(-1), but only 41 at 407 g kg super(-1). Three by-products of poultry slaughtering and three legume seeds replaced WG at levels of 250 and 500 g kg super(-1) in a basal diet of WG-lys, minerals and vitamins. Soy beans had been pressure cooked at one of two intensities, and field beans and fields peas were either untreated or had been autoclaved. D of energy and crude protein was hardly affected by dietary proportion in poultry blood mean (84 and 85%), poultry offal meal (80 and 81%) and incompletely pressure cooked soy beans (82 and 90%); increasing dietary proportions from 250 to 500 g kg super(-1) reduced the respective values of feather meal (88-81 and 86-83%), raw (43-32 and 76-70%) and autoclaved field beans (67-57 and 89-86%), as well as raw (47-39 and 86-83%) and autoclaved field peas (65-40 and 91-86%). At the higher proportion, D of energy of completely pressure cooked soy beans was reduced from 91 to 86%, but that of crude protein was constant at 94%

Digestibility ;  Diets ;  Feed composition ;  Feeding experiments ;  Animal nutrition ;  Fish culture ;  Oncorhynchus mykiss ;