Abstract: Minimum pressure valve having a housing (13) with an inlet (14) and an outlet (15) and in which has been provided a valve body (21) which is pushed against a seating (30) round the inlet (14) in a closed position, and whereby the valve body (21) is situated at a distance from the above-mentioned seating (30) in an open position, such that the inlet (14) is connected to the outlet (15), whereby the valve body (21) is provided in a sliding manner in a valve casing (17) confining, together with the valve body (21) an inner space (36) that is connected to the inlet (14) via a duct (35).

Abstract: A rearing fodder of extruded fodder type, comprising proteins, fats and carbohydrates, for freshwater fish, wherein the fish is larger than 2 grams, and wherein the freshwater has a content of CO2 being above 5 milligrams/litre, wherein the fodder has an increased content of at least one of the minerals: phosphate (P), potassium (K), calcium (Ca), sodium (Na) and magnesium (Mg) beyond what exists naturally in the used protein raw materials, fat raw materials and carbohydrate raw materials, wherein the collective amount of minerals in the extruded fodder is at least 10%, on a dry substance basis, of the total weight of the fodder, and wherein one or more of the minerals phosphate (P), potassium (K), calcium (Ca), sodium (Na) and magnesium (Mg) is/are added beyond what exist in the used protein raw materials, fat raw materials and carbohydrate raw materials.