EFFECTS OF DIETARY PROTEIN
AND LIPID LEVEL ON GROWTH AND BODY COMPOSITION OF JUVENILE AYU (plecoglossus
altivelis) reared in seawater
S.-M. Lee, D.-J. Kim, S.H. Cho-2002
Aquaculture
Nutrition, 8(1): 53-58
Abstract :
A 3 (protein levels, 380, 460 and 520 g kg-1
diet) x 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.
(Faculty of Marine Bioscience and Technology,
Kangnung National University, Kangnung 210-702, Korea. e-mail: smlee@knusun.kangnung.ac.kr)