Effects of dietary protein and lipid level on growth and body composition of juvenile ayu (Plecoglossus altivelis ) reared in seawater

Abstract

A 3 (protein levels, 380, 460 and 520 g kg–1 diet) × 2 (lipid levels, 65 and 140 g kg–1 diet) factorial experiment with three replicates was conducted. Weight gain, feed efficiency and daily feed intake were not significantly affected by dietary protein level, but were by dietary lipid level. Weight gains of fish fed 65 g lipid kg–1 diet were significantly, or slightly, higher than for 140 g lipid kg–1 diet at all protein levels. Daily protein intake was significantly affected by both dietary protein and lipid levels (P < 0.002). Daily lipid intake was not significantly affected by dietary protein level, but was by dietary lipid level (P < 0.001). Protein efficiency ratio was significantly affected by dietary protein level (P < 0.02), but not by dietary lipid level. Protein efficiency ratio tended to improve with the decrease of dietary protein level at the same lipid level. Moisture, protein and lipid contents of whole fish were significantly affected by dietary lipid level (P < 0.01). Increased dietary lipid did not improve growth or feed efficiency, but increased body fat deposition. It was concluded that the optimum dietary protein and lipid level for growth of juvenile ayu may be 380 and 65 g kg–1 diet, respectively, when fish were fed to satiety three times daily in seawater.

Effect of dietary protein and lipid levels on growth, nutrient utilization and whole‐body composition of blue gourami, Trichogaster trichopterus fingerlings

“…But the whole‐body protein and ash contents were unaffected by increase in dietary lipid content at the same level of dietary protein. Similar results were reported in other fish species (Lee et al., 2002; for ayu, Plecoglossus altivelis ; Tibbetts et al., 2005; for haddock, M. aeglefinus ; Cho et al., 2005; for turbot, Scophthalmus maximus ; and Schulz et al., 2007; for pike perch, S. luciperca ). However, at the same level of dietary lipid, with increase in dietary protein, there was a significant decrease in whole‐body lipid content, but the protein and ash content remained unaffected, which is in contrast to the results obtained by Li et al.…”

Effect of varying dietary protein levels on growth, feeding efficiency, and proximate composition of yellow snapper

“…These lower values were obtained after many years of research in those species, which allow implementing more profitable diets (Houlihan et al, 1988;Catacutan & Coloso 1995;Pérez et al, 1997;Webb & Gatlin III, 2003). For FER, our best value (42.56) was obtained for fish fed with 55% protein diet; this is lower than those reported for red drum (98.7), rockfish (82.0), and ayu (Plecogglossus altivelis) (63.8) (Thoman et al, 1999;Lee et al, 2002aLee et al, , 2002b (Houlihan et al, 1988;Santhina et al, 1996;Gouveia & Davies 2000;Alvarez-González et al, 2001;Lee et al, 2002a;Espinos et al, 2003;Webb & Gatlin III et al, 2003). This agrees with the poor WG% obtained for our fish (82.6-125.92) for a trial period of 95 days.…”

Effects of dietary protein levels on growth, feed utilization, protein retention efficiency and body composition of young Heteropneustes fossilis (Bloch)

“…However, the amount of NH 3 in the surrounding water of the fish fed high protein diet might have not affected the growth and health status of the fish, as the feeding trial was conducted in troughs fitted with water flowthrough system at 1-1.5 l/min. The decrease in weight gain at protein levels above the optimum level may also be because of a reduction in available energy for growth and due to inadequate non-protein energy necessary to deaminate and excrete excess absorbed amino acids (Jauncey 1982;Cho et al 1985;Vergara et al 1996;Kim et al 2002) Decrease in the protein utilization beyond requirement level of dietary protein is a well-documented phenomenon (Jobling and Wandshik 1983;Daniels and Robinson 1986;Tibbetts et al 2000;Catacutan et al 2001;Ng et al 2001;Kim et al 2002;Lee et al 2002;Yang et al 2002;Deepak and Garg 2003;Sales et al 2003;Yang et al 2003;Islam and Tanaka 2004;Kalla et al 2004;Luo et al 2004;Cho et al 2005;Jacinto et al 2005;Kim and Lee 2005;Tibbetts et al 2005;Sa et al 2006). In the present study, PER and protein retention efficiency increased with the increase in dietary protein content up to 40% and then decreased with further elevation of dietary protein level at 45 and 50% (Diets 5 and 6) which is also evident in other studies (Lee and Putnam 1973;Bromley 1980;Pongmaneerat and Watanabe 1991;Lee et al 2002).…”