LINEAR PROGRAMMING AND THE FORMULATION OF LEAST COST DIETS FOR TILAPIA, OREOCHROMIS NILOTICUS

Feed costs represent about 30% to 50% of total variable costs in semi-intensive fish culture systems in Egypt. Feed therefore has a major role in the economics of such enterprises. A linear programming model was developed to formulate least cost diets for tilapia with protein levels of 23% to 30%. Diets were formulated subject to limits imposed on their content of protein, fiber, phosphorus, fat, carbohydrates, metabolizable energy, lysine and sulfur amino acids, and cottonseed meal. Data regard­ing feed ingredient composition and prices, nutrient requirements of tila­pia, and limits on the use of certain feed ingredients were obtained from primary and secondary sources. Results indicated the importance of fish­meal, cottonseed meal, rice bran with germ, poultry by-products, and wheat bran in feed formulation. The cost of feed ingredients was 435 L.E. per ton for the 23% protein diet, and increased by 12 L.E. for each additional 1% protein. There is a need to quantify the economic effects of different dietary protein levels and dietary inclusion levels of cotton­seed meal on tilapia yield and producer's profits under local field condi­tions.