Dietary protein and lipid nutrition of marble goby, Oxyeleotris marmoratus juvenile

• Main Author: Ooi, Shing Yau
• Format: Thesis
• Language: English; English
• Published: 2014
• Subjects: SH151-179 Fish culture
• Online Access: https://eprints.ums.edu.my/id/eprint/42787/1/24%20PAGES.pdf; https://eprints.ums.edu.my/id/eprint/42787/2/FULLTEXT.pdf; https://eprints.ums.edu.my/id/eprint/42787/

Three feeding experiments were conducted to investigate the dietary protein and lipid and the utilization of soybean meal in the diet by marble goby, Oxyeleotris marmoratus juvenile. Three isolipidic (10%) diets were formulated in Experiment I to contain 40, 45 and 50% of dietary protein (as P40, P45 and P50, respectively) and fed to juveniles of initial body weight (BW) 1.93 ± 0.01g. In Experiment II, four isonitrogenous (48% protein) diets containing different levels dietary lipid at 10, 14, 18 and 22% (as L10, L14, L18 and L22, respectively) was fed to groups of juveniles with initial BW:2.76 ± 0.02g. In Experiment III, three isonitrogenous (48% protein) and isolipidic (10% lipid) diets were formulated by replacing 0, 20% of the fishmeal protein with defatted soybean meal protein and 20% soybean meal with 2000 FTU/kg of phytase supplementation (as SB0, SB20 and SB20+PT, respectively) and fed to juveniles with initial BW 0.28 ± 0.01g. Experiment duration for Experiment I and II was 15 weeks while Experiment III was 40 days. In each of the feeding trials, a recirculation culture system was used and water quality was monitored periodically. Before commencing the feeding trials, all juveniles were weaned to formulated feed. During experiments, juveniles were fed to apparent satiation twice times daily. At the end of the feeding trial, some juveniles from each treatment were sacrificed for body indices and whole body proximate analysis. The remaining juveniles in Experiment I and II were used to collect faeces for apparent digestibility test in each respective experiment. The results of Experiment I showed that diet P45 which contained 48.6% protein supported highest growth, final BW, specific growth rate (SGR), protein efficient ratio (PER), nitrogen retention efficiency (NRE), apparent protein and lipid digestibility coefficient; and significant better feed conversion ratio (FCR) (P<0.05) than other treatments. Results of Experiment II showed that L10 that contained 10% of dietary lipid led to highest growth, SGR, final BW, PER; and significant lower hepatosomatic index, viscerosomatic index and intraperitoneal fat (P<0.05) than other treatments. Experiment III showed that 20% of soybean meal protein replacement was too high for small size of marble goby juvenile in term of growth, PER and FCR. However, juveniles fed SB20+PT achieved higher growth, FCR and PER compared with fish fed SB20. This present study showed that juveniles fed dietary protein and lipid of 48.6% and 10% achieved highest growth and the increase of protein or lipid higher than this level did not supported higher growth and the supplementation of phytase had improved the soybean meal utilization by young marble goby juvenile.