Effect of different feeding regimes on the growth of tilapia chitralada (Oreochromis niloticus Linnaeus, 1757) cultured in cages

Abstract

This study evaluated different levels of crude protein (CP) at different stages of growth of tilapia (Chitralada) in cages. Diets with three protein levels (36, 32 and 28%) at three growth phases (I - 80 to 300 g; II - 301 A 650 g and III - 651 and 1,000 g) were used, so as a randomized block experimental design with different feeding programs: 1) control: 36, 32 and 32%, 2) 32, 32 and 32%, and 3) 32, 32 and 28%. Fishes were stocked at densities of 400, 200 and 150 individuals m^-3 in phases I, II and III, respectively. Feeding was carried out based on the feeding program, feed intake and water quality. Daily, temperature, pH and dissolved oxygen, and monthly, ammonia, nitrite, nitrate, inorganic phosphate, alkalinity, hardness and total chlorophyll a were monitored. Data on growth and yield between treatments were submitted to ANOVA (P â"°¤ 0.05). Fish reared in phases I (80-300 g) and III (651-1,000 g) performed better (P â"°¤ 0.05) when fed diet 32%, while those reared in Phase II (301-650 g), fed with diet 36% CP in the previous phase, showed the best performance. In conclusion, the feeding management more efficient for the three phases of size was obtained with the extruded ration with 32% crude protein.