Untersuchungen über den Mineralstoff-Bedarf von Regenbogen-Forellen (Salmo Gairdneri, R.)

Abstract

Diets with varying mineral contents were fed to rainbow trout initially weighing about 7 g each. During 100 days of the trial, good growth rates and food conversion ratios could be observed when diets contained only 2.0 g Ca, 3.4 g P, 0.3 g Mg, 1.6 g K and 2.2 g Na. Significant amounts of Ca, Mg and K must have been absorbed from the water, as retentions of these elements exceeded the amounts fed. With increasing supply of P, retention of P, Ca and Mg increased. Utilization of P from Na2HPO4 was superior to that from ash of fish meal.