Effects of shrimp head meal in the diets on growth, feed efficiency and pigmentation of sex-reversed red tilapia, Oreochromis niloticus x O. mossambicus

Shrimp head meal (SHM) was used to replace fish meal as a protein source in practical diets for sexreversed red tilapia (Oreochromis niloticus x O. mossambicus) at 0, 25, 50, 75 and 100% of fish meal protein or 0, 6.92, 13.84, 20.76 and 27.68% by weight of diet respectively. Catfish feed that contained protein content 37.22±0.10% was included as a reference diet. The experimental diets were fed to the fish with mean initial weight of 3.13±0.05 g for 8 weeks in 70 l aquaria. The results showed that weight gain and specific growth rate of fish fed 50% of fishmeal protein replacement or diet 3 was not significant by different from those of fish on control diet (p>0.05). The data of feed intake, feed conversion ratio and productive protein value of fish fed diet 3 were equal to those fed control diet (p>0.05). The lowest growth rate and feed efficiency showed on fish fed 100% of fishmeal protein replacement. The production cost of fish fed diet 3 was equal to those fed the control diet and the reference diet (p>0.05). Total carotenoid content in fish skin was significantly highest (p