A study of nitrogen excretion and oxygen consumption in five half-sib families of rainbow trout

Abstract

Summary. Branchial and urinary nitrogen (ammonia and urea) excretion and oxygen consumption rates were measured in five half-sib families of rainbow trout showing different growth rates. Ammonia loss through the gills represented the major part of nitrogen excretion and was highly correlated to nitrogen intake (NI). The fish of families 1 and 2 with better growth rates and food conversion ratios excreted much less nitrogen (51 and 59 % of NI, respectively) than the other 3 families (58 to 75 % of NI). Urea excretion and oxygen consumption rates varied but showed no definite relation to the growth rates of the families. Biochemical utilization of dietary proteins seemed to vary in rainbow trout, and further research along these lines is required.Introduction.

The impact of varying feeding regimes on oxygen consumption and excretion of carbon dioxide and nitrogen in post-smolt Atlantic salmon Salmo salar L.

“…This confirms the results of other studies on salmonids, such as Juvenile sockeye salmon Oncorhynchus nerka (Walbaum) (Brett & Zala 1975), juvenile and post-smolt Atlantic salmon (Wiggs, Henderson, Saunders & Kutty 1989;Fivelstad et al 1990), juvenile Arctic chart {Salvelinus alpinus Linnaeus) (Fivelstad etal. 1990) and various sizes of rainbow trout (Kaushik 1980;Beamish & Thomas 1984;Kaushik. Fauconneau & Blanc 1984;Clarke etal.…”

Nitrogenous excretion in juvenile turbot, Scophthalmus maximus (L.), under controlled conditions

“…Quantification of nitrogenous excretion in fish has been recognized to be of major interest by many authors because of the importance of water quality in fish culture (Handy & Poxton 1993) and transportation, and the fact that any improvement of dietary protein utilization by fish makes an evaluation of nitrogenous waste production necessary (Kaushik. Fauconneau & Blanc 1984).…”

“…Kjorsvik&Haug 1990;Gershanovich & Pototskij 1992); intra-species families (Gallagher. Kane & Courtney 1984;Kaushik et al 1984: Ming 1985; and physiological status (Wiggs. Henderson.…”