Dietary Protein Level Affects the Growth Performance of Large Male Genetically Improved Farmed Tilapia, Oreochromis niloticus, Reared in Fertilized Freshwater Cages

Abstract

An 8-wk experiment was conducted to evaluate the effects of dietary protein on the growth performance, body composition, and serum biochemical indices of large male genetically improved farmed tilapia (GIFT), Oreochromis niloticus, reared in fertilized freshwater cages. Six semi-purified diets were formulated, containing 18.05, 22.39, 25.97, 31.62, 35.97, and 39.89% protein (designated as P18, P22, P26, P30, P34, and P38, respectively). Each diet was fed to randomly selected fish (initial mean weight 216.7 g) in four cages. At the end of the experiment, the final body weights varied significantly (P < 0.05), ranging from 520 to 580 g. Fish receiving the P30 diet had the highest final weight value (580.5 ± 5.4 g). Weight gains of fish fed the P26 and P30 diets were significantly higher (P < 0.05) than those fed the P18 and P38 diets. The apparent feed efficiency of fish fed the P18 diet was significantly lower (P < 0.05) than that of fish in the other groups except the P22 group (P > 0.05). The apparent protein efficiency ratio decreased gradually with increasing dietary protein. Whole-body moisture and ash showed no significant difference (P > 0.05), but protein and fat content were significantly affected by dietary protein level (P < 0.05). No significant differences were found for serum total protein, triglyceride, total cholesterol, glutamic-oxaloacetic transaminase, and glutamic-pyruvic transaminase levels among different diets (P > 0.05); only serum glucose level was affected by dietary protein levels (P < 0.05). Second-order polynomial regression of weight gain suggested 29.3% dietary protein is adequate content for maximum growth of large male GIFT, O. niloticus. Abbas, G. and P. J. A. Siddiqui. 2013. The effects of varying dietary protein level on growth, feed conversion, body composition and apparent digestibility coefficient of juvenile mangrove red snapper, Lutjanus argentimaculatus (Forsskal 1775). Aquaculture Research 44:807-818. Abdel-Tawwab, M. 2012. Effects of dietary protein levels and rearing density on growth performance and stress response of Nile tilapia, oreochromis niloticus (L.). International Aquatic Research 4:1-13. Abdel-Tawwab, M., M. A. A. Mousa, and F. E. Abbass. 2007a. Growth performance and physiological response of African catfish, Clarias gariepinus (B.) fed organic selenium prior to the exposure to environmental copper toxicity. Aquaculture 272:335-345. Abdel-Tawwab, M., A. E. Abdelghany, and M. H. Ahmad. 2007b. Effect of diet supplementation on water quality, phytoplankton community structure, and the growth of Nile tilapia, Oreochromis niloticus (L.), common carp, Cyprinus carpio (L.), and silver carp, Hypophthalmichthys molitrix (V.), polycultured in fertilized earthen ponds. Journal of Applied Aquaculture 19:1-24. Abdel-Tawwab, M., M. H. Ahmad, Y. A. E. Khattab, and A. M. E. Shalaby. 2010. Effect of dietary protein level, initial body weight, and their interaction on the growth, feed utilization, and physiological alterations of Nile tilapia, Oreochromis niloticus (L.). Aqua...

Dietary protein requirement for large‐size Songpu mirror carp ( Cyprinus carpio Songpu)

“…For growth performance, the WGR and SGR first significantly increased to a peak and then sharply declined after the peak value; for feed utilization efficiency, the change trend of FCR was inconsistent with that of WGR and SGR. The variation trends obtained in this study corresponded to those reported in Scophthalmus maximus with an IBW of 209.1 g (Liu, Mai, Liufu, & Ai, 2014), Oreochromis niloticus with an IBW of 204.0 g (Xu et al., 2016) and Oreochromis niloticus with an IBW of 216.7 g (Liu et al., 2017), reflecting that excessive dietary protein contents will also result in obvious growth inhibition of fish with the weights beyond 200 g. Additionally, the recommended protein requirement for common carp with the weight range from 200 to 600 g was 320 g/kg according to NRC (2011). However, in the current study, according to the growth performance and feeding utilization, the optimal dietary protein requirement level of large‐size Songpu mirror carp ( C. carpio Songpu) with an IBW of 246.00 ± 17.36 g seems to be approximately 260 g/kg, which was obviously lower than that recommended by the NRC (2011), and the result was also 40–50 g/kg lower than that reported in common carp ( C. carpio ) with an IBW of 4.11 ± 0.91 g (Gao et al., 2015), common carp ( C. carpio ) with an IBW of 10.15 ± 1.15 g (Sun et al., 2016), common carp ( C. carpio ) with an IBW of 55.37 ± 3.55 g (Fan et al., 2018) and common carp ( C. carpio ) with an IBW of 75.39 ± 0.18 g (Wu et al., 2011).…”

The optimum dietary protein requirement of the genetically improved farmed tilapia ( GIFT : Oreochromis niloticus ): Effects on growth performance and protein metabolism via GH‐IGF axis and TOR signalling pathway at different seasonal growth stages

“…In Stage 1, it was shown that the protein content of whole body increased with the increase in dietary protein levels, which was in accordance with the findings of Kim et al (2016) on juvenile parrot fish ( Oplegnathus fasciatus ) and Wang et al (2016) on juvenile red spotted grouper ( Epinephelus akaara ). Similar findings were also reported in GIFT tilapia that the highest dietary protein group obtained the largest body protein content (Liu et al, 2017). However, it was found that no significant changes in the body protein contents with the increasing dietary protein levels in juvenile black buffalo ( Ictiobus niger ) fed in the indoor recirculating aquaculture systems (RAS) (volume of tanks: 430 L and culture temperatures: 21–23°C) (Guy et al, 2018).…”

“…In Stage 1, it was shown that the protein content of whole body increased with the increase in dietary protein levels, which was in accordance with the findings of Kim et al (2016) on juvenile parrot fish (Oplegnathus fasciatus) and Wang et al (2016) on juvenile red spotted grouper (Epinephelus akaara). Similar findings were also reported in GIFT tilapia that the highest dietary protein group obtained the largest body protein content (Liu et al, 2017).…”

“…Previous reports on fish protein requirements have also shown that dietary protein has different effects on fish body composition (Kim et al, 2016; Liu et al, 2017). In this stage, the lipid content of the fish body gradually decreased with an increase in dietary protein, while the protein and moisture showed a generally increasing trend.…”