Journal of The World Aquaculture Society, Jan 1, 2003
An 8-wk feeding trial was conducted with a 3 ± 4 factorial design for evaluating the nutritional ... more An 8-wk feeding trial was conducted with a 3 ± 4 factorial design for evaluating the nutritional relationship between phospholipids (lecithin at 0, 1.5% or 3% of diet) and choline chloride (0, 1,000, 2,000, or 4,000 mg/kg diet) in juvenile Litopenaeus vannamei. In addition, diets with five graded levels of choline chloride (0, 500, 1,000, 2,000, and 4,000 mg/kg) without supplemental phospholipids or cholesterol were fed for determining the dietary choline requirement. Overall survival was 99% with no difference among the dietary treatments. The choline requirement was estimated to be 871 mg/kg diet without dietary phospholipids. No choline requirement was evident when lecithin was provided at 1.5% and 3% of diet. Shrimp growth significantly increased with incremental dietary phospholipids regardless of choline chloride level. These results indicate that lecithin could effectively provide choline. Conversely, synthesis of phospholipids from choline could not meet the phospholipids requirement of shrimp. Both dietary lecithin and choline chloride supplementation reduced lipid in shrimp muscle. However, only lecithin supplementation increased lipid in hepatopancreas, and dietary choline chloride decreased the level of other phospholipids (except phosphatidylcholine) in shrimp muscle.
Journal of Experimental Marine Biology and Ecology, Jan 1, 2000
Excretion rates of ammonia-N, nitrite-N, nitrate-N, and dissolved organic nitrogen (DON) for juve... more Excretion rates of ammonia-N, nitrite-N, nitrate-N, and dissolved organic nitrogen (DON) for juvenile Litopenaeus vannamei (3.85±0.83 g) were quantified in response to nine different combinations of temperature (24, 28, and 32°C) and salinity (10, 25, and 40 ppt) under laboratory conditions. Results indicated that L. vannamei is ammonotelic, with ammonia-N accounting for 61.9–84.3% of total nitrogen (TN) excretion. There were significant effects of temperature and salinity, but no significant interaction between them, on ammonia-N excretion rate (RAN). RAN increased with increasing temperature, over the interval 24–32°C. RAN was lower at 25 ppt than at 10 and 40 ppt, at all temperatures. DON excretion rate (RDON) was not significantly influenced by either temperature or salinity; the overall mean RDON was about 5.24 μg-N g −1 h −1. However, the percentages of DON in TN (PDON) varied from 15.4 to 36.4% under the various temperature–salinity combinations. PDON at 28 and 32°C was significantly lower than at 24°C, and PDON at 10 ppt was significantly lower than at 25 and 40 ppt. Only very small amounts of nitrogen were excreted by L. vannamei as nitrite-N and nitrate-N.
Two experiments were conducted to investigate the active components of soybean lecithin for juven... more Two experiments were conducted to investigate the active components of soybean lecithin for juvenile Litopenaeus vannamei. The first experiment was conducted to determine the dietary phosphatidylcholine (PC) requirement of juvenile L. vannamei, and to investigate whether other phospholipids (PL), mainly phosphatidylethanolamine (PE) and phosphatidylinositol (PI) were the active fractions of soybean lecithin. Seven levels of PC (0%, 0.35%, 0.7%, 1.4%, 2.1%, 2.8%, 4.2%) extracted from soybean lecithin (PC purity 93%) were used to determine the PC requirement; also, PE and PI (in a 25:22 proportion) were tested at 0.84% and 1.68% levels with PC levels controlled at 0.35% and 0.52% of diet to investigate the combined PE and PI effects. Results showed that no dietary PC requirement was evident based on shrimp growth and survival. Increasing purified PC in the diet decreased total lipid, free fatty acid and other PL levels in shrimp hepatopancreas (mid-gut gland) and increased PC level in shrimp muscle. However, other PL, mainly PE and PI, showed significant enhancing effects on shrimp growth when PC was provided at 0.35% or 0.52% of diet.Another 4×2 factorial experiment was concluded to reevaluate the requirement of shrimp for PC by including purified PC at 0%, 0.7%, 1.4 % and 2.8% of diet with or without 0.1% cholesterol in the diet. A diet containing 1.4% PC provided by deoiled lecithin also was tested for comparison. Results showed no interaction between PC and cholesterol on shrimp growth, survival and feed conversion ratio (FCR). Compared with the apparent growth-enhancing effect of dietary cholesterol, the effect of purified PC was negligible. With PC at 1.4% of diet, the presence of other PL from lecithin or 0.1% cholesterol significantly enhanced shrimp growth and FCR.In summary, purified soybean PC showed different effects from deoiled lecithin on shrimp growth, lipid composition, and relationship with dietary cholesterol. Beneficial effects of soybean lecithin on growth of L. vannamei could be attributed to the presence of PL other than PC in the diet under the experimental conditions of this study.
Journal of The World Aquaculture Society, Jan 1, 2003
An 8-wk feeding trial was conducted with a 3 ± 4 factorial design for evaluating the nutritional ... more An 8-wk feeding trial was conducted with a 3 ± 4 factorial design for evaluating the nutritional relationship between phospholipids (lecithin at 0, 1.5% or 3% of diet) and choline chloride (0, 1,000, 2,000, or 4,000 mg/kg diet) in juvenile Litopenaeus vannamei. In addition, diets with five graded levels of choline chloride (0, 500, 1,000, 2,000, and 4,000 mg/kg) without supplemental phospholipids or cholesterol were fed for determining the dietary choline requirement. Overall survival was 99% with no difference among the dietary treatments. The choline requirement was estimated to be 871 mg/kg diet without dietary phospholipids. No choline requirement was evident when lecithin was provided at 1.5% and 3% of diet. Shrimp growth significantly increased with incremental dietary phospholipids regardless of choline chloride level. These results indicate that lecithin could effectively provide choline. Conversely, synthesis of phospholipids from choline could not meet the phospholipids requirement of shrimp. Both dietary lecithin and choline chloride supplementation reduced lipid in shrimp muscle. However, only lecithin supplementation increased lipid in hepatopancreas, and dietary choline chloride decreased the level of other phospholipids (except phosphatidylcholine) in shrimp muscle.
Journal of Experimental Marine Biology and Ecology, Jan 1, 2000
Excretion rates of ammonia-N, nitrite-N, nitrate-N, and dissolved organic nitrogen (DON) for juve... more Excretion rates of ammonia-N, nitrite-N, nitrate-N, and dissolved organic nitrogen (DON) for juvenile Litopenaeus vannamei (3.85±0.83 g) were quantified in response to nine different combinations of temperature (24, 28, and 32°C) and salinity (10, 25, and 40 ppt) under laboratory conditions. Results indicated that L. vannamei is ammonotelic, with ammonia-N accounting for 61.9–84.3% of total nitrogen (TN) excretion. There were significant effects of temperature and salinity, but no significant interaction between them, on ammonia-N excretion rate (RAN). RAN increased with increasing temperature, over the interval 24–32°C. RAN was lower at 25 ppt than at 10 and 40 ppt, at all temperatures. DON excretion rate (RDON) was not significantly influenced by either temperature or salinity; the overall mean RDON was about 5.24 μg-N g −1 h −1. However, the percentages of DON in TN (PDON) varied from 15.4 to 36.4% under the various temperature–salinity combinations. PDON at 28 and 32°C was significantly lower than at 24°C, and PDON at 10 ppt was significantly lower than at 25 and 40 ppt. Only very small amounts of nitrogen were excreted by L. vannamei as nitrite-N and nitrate-N.
Two experiments were conducted to investigate the active components of soybean lecithin for juven... more Two experiments were conducted to investigate the active components of soybean lecithin for juvenile Litopenaeus vannamei. The first experiment was conducted to determine the dietary phosphatidylcholine (PC) requirement of juvenile L. vannamei, and to investigate whether other phospholipids (PL), mainly phosphatidylethanolamine (PE) and phosphatidylinositol (PI) were the active fractions of soybean lecithin. Seven levels of PC (0%, 0.35%, 0.7%, 1.4%, 2.1%, 2.8%, 4.2%) extracted from soybean lecithin (PC purity 93%) were used to determine the PC requirement; also, PE and PI (in a 25:22 proportion) were tested at 0.84% and 1.68% levels with PC levels controlled at 0.35% and 0.52% of diet to investigate the combined PE and PI effects. Results showed that no dietary PC requirement was evident based on shrimp growth and survival. Increasing purified PC in the diet decreased total lipid, free fatty acid and other PL levels in shrimp hepatopancreas (mid-gut gland) and increased PC level in shrimp muscle. However, other PL, mainly PE and PI, showed significant enhancing effects on shrimp growth when PC was provided at 0.35% or 0.52% of diet.Another 4×2 factorial experiment was concluded to reevaluate the requirement of shrimp for PC by including purified PC at 0%, 0.7%, 1.4 % and 2.8% of diet with or without 0.1% cholesterol in the diet. A diet containing 1.4% PC provided by deoiled lecithin also was tested for comparison. Results showed no interaction between PC and cholesterol on shrimp growth, survival and feed conversion ratio (FCR). Compared with the apparent growth-enhancing effect of dietary cholesterol, the effect of purified PC was negligible. With PC at 1.4% of diet, the presence of other PL from lecithin or 0.1% cholesterol significantly enhanced shrimp growth and FCR.In summary, purified soybean PC showed different effects from deoiled lecithin on shrimp growth, lipid composition, and relationship with dietary cholesterol. Beneficial effects of soybean lecithin on growth of L. vannamei could be attributed to the presence of PL other than PC in the diet under the experimental conditions of this study.
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