Feed is by far the single largest cost component of barramundi farming and accounts for about 35% of on-farm operating costs. Reducing feed costs by better tailoring dietary specifications to the nutrient requirements of the fish, by providing these nutrients at least cost and by adopting feeding practices that optimise productivity will greatly assist farm profitability. In Australia, barramundi are pond-reared over latitudes from 5°S to 22°S and this results in large seasonal variations in water temperature and consequently, in growth rate of the fish.

The research conducted in this project sought primarily to characterise the effect of water temperature on fish productivity and how modification of dietary nutrient specifications and/or feeding practices could assist in improving farming profitability. This entailed research to define the fish's response to changes in dietary supply of critical nutrients over a range of water temperatures. Research examining the efficacy of crystalline amino acids in diets for barramundi was carried out in a supplementary project (FRDC 95/69); research on the nutritive value of terrestrial feed ingredients and their suitability as replacements of fishmeal in diets for barramundi is reported in FRDC 93/120-04.