Gurure RM ; Moccia RD ; Atkinson JL ;

Aquaculture Nutrition vol. 1 (4)   pp. 227-234, 1995

Dep. Anim. and Poultry Sci., Univ. Guelph, Guelph, ON N1G 2W1 Canada

Young Arctic charr, Salvelinus alpinus (L.), mean weight 2.56 plus or minus 0.02 g, were fed nine isoenergetic ( similar to 16.6 MJ digestible energy (DE)/kg) practical diets formulated to supply digestible crude protein (DCP) at 40 g/kg increments from 230 to 550 g/kg, for 84 days. Mean weight gain (MWG) and specific growth rate (SGR) were determined every 14 days while carcass composition was determined at the start and end of the experiment. Growth responses attained the highest values in the fish fed the diet with 350 g/kg DCP. Carcass moisture gain, protein gain and apparent net lipid accumulation increased as DCP levels increased to a maximum at 350 g/kg after which there were no differences among treatments. Total carcass lipid and lipid gain decreased as dietary DCP increased up to 470 g/kg with no differences thereafter. Apparent net protein accretion decreased with increasing DCP levels up to 350 g/kg after which there were few differences among treatments. Protein requirements were estimated by fitting MWG and SGR data to broken line regression, quadratic and saturation kinetics models. Results from these analyses suggest that dietary DCP should be provided at between 340 and 392 g/kg (equivalent to similar to 370 and 420 g/kg crude protein) for optimal growth of young Arctic charr reared in similar conditions

Diets ;  Juveniles ;  Fish culture ;  Proteins ;  Nutritional requirements ;  Feeding experiments ;  Salvelinus alpinus ;