Abstract: The present invention relates to a process for preparing highly digestible feed that may be used among others as feed for aquaculture, by a yeast treatment characterized in that yeast cells are processed to hydrolyze at least partially the external layer of the cell wall without damaging the wall itself.

Abstract: Artemia (14,90) are kept under such conditions as high density in a flowing aqua-culture (2) that either nauplii (90) or cysts (14) are deposited as offspring (14,90).A treatment inducing cyclic cysts production consists of a cyclic reduction of the oxygen concentration of the flowing aqua-culture (2).A device (1,44) for depositing only one selected type of offspring (14,90) comprises for the production of cysts (14) inducing means (12,53,64,67) for the cyclic reduction of the oxygen concentration.A packing (67) of such offspring (14,90) is provided with a label (68) indicating a specification predetermined by the conditions the flowing aqua-culture (2) had been operated at.Methods for feeding Artemia (14,90) are characterized by the use of agricultural derivatives (7) and/or chicken manure (7).A method for preparing food (14,90) is characterized by the use of nauplii (90) and/or cysts (14) produced in the flowing aqua-culture (2) and/or by the use of particles coated with a food additive.