Effects of dietary protein and lipid content on growth performance and biological indices of iridescent Shark (Pangasius hypophthalmus, Sauvage 1878) fry |
| |
| Authors: | Preeda Phumee Roshada Hashim Mohammed Aliyu-Paiko & Alexander Chong Shu-Chien |
| |
| Institution: | Laboratory of Aquafeed and Feeding Management, Aquaculture Research Group, School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia |
| |
| Abstract: | Dietary protein and lipid effects on growth, body composition and indices of iridescent Shark Pangasius hypophthalmus (Sauvage 1878) fry were studied using a 4 × 2 factorial design. Triplicate groups of 10 fish per tank, with initial mean weights of 3.54–3.85 g were fed eight isocaloric diets comprising a combination of four protein levels (250, 300, 350 and 400 g kg?1 or 25%, 30%, 35% and 40%) and two lipid levels (60 and 120 g kg?1 or 6% and 12%) respectively. The fish were hand-fed to satiety twice daily for 8 weeks. Specific growth rate (SGR) and feed conversion ratio (FCR) showed significant effects ( P <0.05) with variations in dietary protein and lipid. The highest SGR was observed in fish fed 40% protein/12% lipid diet but this value was not significantly ( P >0.05) different from the fish fed 30% protein/12% lipid diet. The FCR was lowest for the 40/12 diet and differed significantly only with the 25/6, 25/12 and 30/6 treatments respectively. The hepatosomatic index (HSI) was significantly affected by the level of protein, but intraperitoneal fat (IPF) showed significant variation due to dietary lipid level. The HSI significantly ( P <0.05) decreased when dietary protein increased from 25% to 30% but increased marginally thereafter. The IPF values increased with increased dietary lipid but decreased with increased dietary protein. Body protein was positively correlated with dietary protein content; conversely, body lipid content decreased with increase in dietary protein. The results of this experiment indicate the presence of a protein-sparing effect of lipid as fish fed 30% protein/12% lipid diet had growth and feed utilization comparable to those fed 40% protein/12% lipid diet. |
| |
| Keywords: | protein lipid protein sparing Pangasius hypophthalmus growth |
|
|
