Quality control techniques used in the rearing of Nile tilapia, Oreochromis niloticus, in net cages

Abstract

This work presents the result of observations accomplished for 168 days in the Station of Pisciculture of the State University of Londrina - EPUEL, with the objective of to locate the main problems, to quantify them and to solve them using techniques of quality control. The experiment was based on observations of 120 juvenile specimens of sexually reverted Nile tilapia, with an initial mean weight of 116.65 ± 0.85 g, distributed in a completely randomized design. The values of the monthly average temperature reveal to be "out of statistic control†and show, through the application of the capacity rates (Cp and Cpk), that 42.07% are below the inferior limit of specification (LIE), indicating that the medium temperature during the cultivation was low in relation to ideal temperature for the tilápias rearing. Techniques of Pareto, Knapsack Problem and Control Charts were used, and their results presented the solution for the problems of predators and biometrics with the maximized Z* objective function.