If world aquaculture development is to be realised in the form of semi-intensive and intensive farming systems, as is generally believed, then considerable inputs of fertilizer and feed will have to be provided. It is not surprising therefore that fish and shrimp nutrition has become one of the most important research and development components within aquaculture development today; food and feeding costs generally constituting the highest operating cost item of semi-intensive and intensive aquaculture enterprises.
The development of a semi-intensive or intensive feeding regime for fish or shrimp requires first a basic understanding of the nutrition and dietary nutrient requirements of the animal. With the exception of water and energy, the dietary nutrient requirements of all aquaculture species can be considered under five different nutrient groups; proteins, lipids, carbohydrates, vitamins, and minerals. The science of aquaculture nutrition and feeding is concerned with the supply of these dietary nutrients to fish or shrimp either directly in the form of an exogenous ‘artificial’ diet or indirectly through the increased production of natural live food organisms within the water body in which the fish or shrimp are cultured. The crucial role played by natural food organisms in the nutrition of fish and shrimp within extensive and semi-intensive pond culture systems contrasts markedly from intensive culture systems, where stocking density is such that natural food organisms play little or no role in the nutrition of the farmed species (Figure 1). Clearly, the nutrition and feeding of fish or shrimp within each culture system must be considered as being unique and evaluated on its own merits.
Figure 1. The role of natural food organisms and artificial feeds in the nutrition of fish and shrimp within extensive, semi-intensive, and intensive pond culture systems.
In this part of the training manual the classification, structure and biological function of the essential nutrients are described, the quantitative dietary nutrient requirements of fish and shrimp critically reviewed, and suggestions given for dietary nutrient levels within practical complete rations for fish and shrimp.