Table 12. Dietary nutritional deficiency, minerals
Minerals	Deficiency signs/syndrome	Measure
Phosphorus	Reduced growth, poor feed conversion, skeletal deformities, curved and enlarged spongy vertebrae	Supplement feed with dicalcium phosphate to supply available phosphorus
Magnesium	Reduced growth, poor feed conversion, sluggishness, nephrocalcinosis	Supplement freshwater feeds with magnesium. Seawater supplies sufficient magnesium
Iron	Reduced growth, anaemia, pale gills	Add iron supplement with high iron bioavailability or blood meal�
Manganese	Poor growth, short body dwarfism, high feed conversion ratio, skeletal abnormalities	Add manganese supplement with high bioavailability of this element
Copper	Reduced growth	Add copper supplements
Zinc	Reduced growth, short body dwarfism, cataracts, fin erosion	Add zinc supplement with high zinc bioavailability �
Selenium	Reduced growth, muscular dystrophy	Add selenium supplement and yeast products
Iodine	Goiter	Add iodine supplements
Source: Lall (2002)