Two feeding trials were carried out to investigate apparent nutrient digestibility of flounder fed experimental diets containing different levels of macro-nutrients by satiation feeding rate (Exp-1) and feeding frequency (Exp-2). Triplicate groups of fish averaging 280 g were fed three experimental diets which contained different levels of carbohydrate, protein and lipid by two feeding regimes (satiation and 80% satiation) and four feeding frequencies (three meals a day, two meals a day, one meal a day and one meal every two days). Feces were collected using a fecal collection column attached to fish rearing tanks for 6 weeks. Apparent digestibilities of dry matter, protein, lipid, energy and carbohydrate were not affected by feeding satiation rate in Exp-1. Apparent protein digestibility was not affected by feeding frequency, whereas affected by dietary composition in Exp-2. Apparent protein digestibility of fish fed a high-protein diet showed a tendency to become higher compared to that of fish fed high-carbohydrate diet and high-lipid diet at the same feeding frequency. Apparent lipid digestibility was not affected by dietary composition, however, affected by feeding frequency. Apparent digestibilities of energy and carbohydrate were affected by both dietary composition and feeding frequency. Apparent digestibities of energy and carbohydrate in fish fed the high-protein diet showed a tendency to become higher compared to that of fish fed the high-carbohydrate diet and high-lipid diet at the same feeding frequency. Apparent digestibities of energy and carbohydrate tended to decrease with increasing of feeding frequency at the same dietary composition.
This feeding experiment was conducted to investigate the effects of dietary inclusion of some additives on growth performance, hematological parameter and fatty acid composition of growing flounder. Triplicate groups of fish (average weight 120 g) were fed one of five diets containing 5% kelp meal (Ke), 10% krill meal (Kr), 1% garlic powder (Ga), 1% citrus meal (Ci) or control diet (Con) without supplementation for 15 weeks. After the feeding experiment, survival was not significantly different among the groups fed the different diets. Weight gain of fish fed the Ci diet was significantly higher than that of fish fed the Kr diet, but not significantly different from Con, Ke and Ga treatments. Feed efficiency and protein efficiency ratio of fish fed the Ga diet were significantly higher than those of fish fed the other diets. Total protein, glucose, GOT, GPT and total cholesterol contents in the plasma were not affected by the dietary additives. Composition of C20:4n-6 in the dorsal muscle of fish fed the Con diet was significantly higher than that of fish fed the other diets. The results of this study suggest that the dietary inclusion of garlic meal at 1% may improve feed utilization of growing flounder.
A feeding trial of two extruded pellets (EPI, 45% crude protein with 7% crude lipid and EP2, 47% crude protein with 10% crude lipid) two satiation rates (satiation and 80% satiation) three feeding frequencies (three, two and one meal a day) factorial design with three replications was carried out to investigate the optimum feeding frequency and satiation rate for growth of juvenile flounder. Flounder averaging 55 g were fed a extruded pellets for 58 days. Daily feed intake was affected by dietary composition, feeding frequency and satiation rate (P0.05), but affected by feeding satiation rate (P0.05). Moisture, crude protein and crude lipid contents of the muscle of fish were affected by satiation rate. Moisture and crude protein contents of the liver were affected by dietary composition. Based on fish performance results, it can be concluded that the proper feeding frequency for the growth of juvenile flounder grown from 55 g to 90 g is two meals a day with satiation feeding, regardless of dietary composition used in this study.
Two feeding trials were conducted to investigate the effects of several dietary additives on growth and feed utilization of juvenile flounder. In the first experiment, three replicate groups of juveniles (average weight 1.5 g) were fed diets with or without wasabi extract and chitosan for 7 weeks. Survival rate, weight gain, protein efficiency ratio, hepatosomatic index and condition factor were not affected by the different dietary additives (P>0.05). Feed efficiency of fish fed the wasabi extract diet was significantly higher than that of fish fed the control diet (P<0.05). Daily feed intake of fish fed the wasabi extract diet was significantly lower than that of fish fed the other diets (P<0.05). In the second experiment, three replicate groups of juveniles (average weight 1.4 g) were fed diets with or without Pophyra powder for 7 weeks. Survival rate and weight gain were not significantly affected by dietary Pophyra powder (P>0.05). Feed efficiency and protein efficiency ratio of fish fed the Pophyra diet were significantly lower than those of fish fed the control diet (P<0.05). The results of these experiments suggest that feed efficiency of juvenile flounder may be improved by dietary supplementation with wasabi extract.
This study was conducted to investigate the effects of protein and lipid levels of extruded pellet on growth and body composition of juvenile flounder. Six extruded dry pellets were formulated to contain two protein levels (50 and 55%) and three lipid levels (8, 12 and 15%). Triplicate groups of fish (initial mean weight 21 g) were hand-fed to apparent satiation two times a day for 9 weeks. Survival, weight gain and daily feed intake were not significantly affected by dietary protein and lipid levels. Feed efficiency and protein efficiency ratio were significantly (P lipids. The contents of moisture, crude protein and lipid in the liver was significantly (P
This study were conducted to investigate the effects of several additives in experimental diets on the growth, feed utilization and body composition of juvenile and grower rockfish. Three replicates of juveniles (3.6 g/fish) and two replicates growers (166 g/fish) were fed the experimental diets containing herb medicines mixture, Artemisia asiatica and Epimedium koreanum for 8 weeks. Dietary supplementation with herb medicines mixture had no beneficial effects on growth and feed utilization of juvenile fish. Weight gain, daily feed intake, condition factor and hepatosomatic index of grower fish fed the diet were not affected by dietary additive (P>0.05). Peed efficiency and protein efficiency ratio of grower fish fed the diet containing herb medicines mixture were significantly higher than those of fish fed the control diet (P0.05). Proximate analysis of whole body, muscle, viscera and liver in the juvenile and grower were not affected by dietary additives (P>0.05). The results of this study suggest that feed efficiency and protein efficiency ratio of grower rockfish may improved by herb medicines mixture supplementation in the diet.
Two feeding experiments were conducted to evaluate the effects of the experimental extruded pellet (EP), commercial EP and raw fish-based moist pellet (MP) on growth of growing flounder (Paralichthys olivaceus). In experiment 1, two replicate groups of the fish (average body weight of ) were fed one of five experimental diets (EP1-EP5) and MP in circular concrete tanks (4.6 m , 0.6 m depth) for 78 days. In experiment 2, in order to evaluate EP in the commercial scale (), flounder (average body weight of ) were fed one of five EPs (EP1-EP5) used in experiment 1, commercial EP (EP6) and two MEPs (MEP4 and MEP6) as moist pellet types which were made from EP4 and EP6, respectively, by being sprayed with a mixture of water and additives for 80 days. In experiment 1, weight gain of fish fed the all EPs was not significantly different from that of MP. Feed efficiency of fish fed the EP4 was highest, and protein efficiency ratio of fish fed the EP4 and EP5 was significantly higher than that of fish fed the MP (P