Nutritional deficiency diseases in fish - Winter school on recent advances in diagnosis and management of diseases in mariculture, 7th to 27th November 2002, Course Manual

During the past two decades, there has been tremendous development in \naquaculture. As aquafarming continues to expand worldwide, production methods have \nshifted from traditional extensive to modified extensive, semi-intensive and intensive \nsystems utilizing modern facilities, equipments and management practices aimed at \nproducing higher yields per unit area. Natural food constitutes an important source of \nnutrients for extensive and improved extensive culture systems, whereas artificial feeds \nare required for semi-intensive and intensive practices. In fish and crustacean aquaculture \nthe feed conversion ratio (FCR) falls in between 0.5 and 2.0 and hence feed represents the \nmajor expense, often accounting for more than 50% of total operating cost.