Effect of dietary supplementation of minerals premix on growth performances and return in red tilapia (Oreochromis nilloticus x Oreochromis mossambicus)

Tilapia is a popular fish for consumers and aquaculture in every part of Thailand. This study was conducted to determine the level of mineral supplementation in the diet for the growth of red tilapia fingerlings, which gave the lower fish production cost. The fingerlings with an initial average weight of 3.1 ± 0.48 g and a length of 2.5±0.24 cm were raised in 3 m3 concrete tank with 1.5 m3 of water volume at 20 fish/m2 stocking density. Fish were fed with pellets diet (28 % crude protein), which contained different levels of mineral supplements (0 (control), 20 and 40 g/Kg) in triplicate replications. The experiment was conducted within 80 days. The results showed that fish fed with diet3 had better average daily weight gain (ADG) and food conversion ratio (FCR) than diet2 and diet1 significantly (P<0.05). The ADG and FCR of fish fed with diet3 showed 0.70 ± 0.02, 1.72 ± 0.02 respectively, but there was a non-significant difference in survival rate from all treatments (P>0.05), and the fish production cost of diet 3 is lower than those in diet1 and diet2. Thus, this experiment concluded that minerals supplementation at the level 40 g/kg diet were suitable for tilapia aquaculture.