Nitrogen, fat and energy balance in rainbow trout fed the experimental diets for 6 weeks1.

SEM, Standard error mean; GNI, Gross nitrogen intake; FN, Faecal nitrogen loss; DNI, Digestible nitrogen intake; BUN, Branchial and urinary nitrogen loss; RN, Retained nitrogen; GFI, Gross fat intake; FF, Faecal fat loss; DFI, Digestible fat intake; RF, retained fat; RF/DF, fat efficiency; GEI, Gross energy intake; FE, faecal energy loss; DEI, digestible energy intake; BUE, branchial and urinary energy loss; MEI, metabolisable energy intake; RE, retained energy.1Values represent least squares (LS) means (n = 3), row means with different superscript letters were significantly different and assigned only if interaction effect was significant (P2HP/EF - High P/E ratio diet with fat as main non-protein energy source; HP/EC - High P/E ratio diet with carbohydrate as main non-protein energy source; LP/EF - Low P/E ratio diet with fat as main non-protein energy source; LP/EC - Low P/E ratio diet with carbohydrate as main non-protein energy source.