Análise económica e desempenho produtivo de juvenis de Tilápia Nilótica (O. niloticus) submetidos a dietas com diferentes níveis de farinha de resíduos de filetagem do bagre africano (C. gariepinus) como fonte de proteína

Abstract

Mozambique's aquaculture sector is in rapid development, although it faces constraints inherent the gap between fish demand and supply due to high input costs. The use of locally available feed materials can help reduce production costs. This research aimed to evaluate the economic viability and zootechnical performance of Nilotic Tilapia juveniles fed different levels of African Catfish fillet meal as a protein source. The study was conducted at the ISPG fish unit in Lionde for 60 days, based on a DCC, with 4 treatments (T1-0%, T2-50%, T3-75% and T4-100%) and 4 repetitions, making 16 experimental units, populated with 25 juveniles each. A total of 400 animals with weight and initial mean compliance of 58.12±7.06g and 102.05 ± 5.22mm, respectively, were used in the study. Diets were balanced using Pearson's square method. The water quality parameters evaluated were pH, dissolved oxygen, temperature and transparency, which were within the optimum ranges for the cultivation of the species under study, except for the temperature that presented minimum and maximum average values of 18.81±1.37 and 24.10±0.35ºC, respectively. The diets with the inclusion of flour from African catfish residues, in the analyzed proportions (0, 50, 75, and 75%), presented a result of zootechnical performance statistically similar to the control diet (P <0.05), but lower economic result. The results indicate that the flour obtained from African Catfish fillet residues can successfully replace fish flour at 50 and 75% without compromising the productive performance of juveniles of Nilotic Tilapia. Total substitution (100%) shows inferior performance, although, in statistical terms, it is similar to the remaining treatments. Economically, FRB showed potential in reducing food costs, the higher the FRB inclusion rate, the lower the production cost/kg was observed.