Dietary Lipid Level (dietary + lipid_level)

Distribution by Scientific Domains

Kinds of Dietary Lipid Level

  • increasing dietary lipid level


  • Selected Abstracts


    Optimization of growout diets for red drum, Sciaenops ocellatus

    AQUACULTURE NUTRITION, Issue 2 2002
    M.J. TURANO
    Because of the high costs associated with feed inputs, as well as increased concern about waste production on fish farms, there is considerable interest in developing growout diets which are both cost effective and low polluting. In two 12-week growth trials, the response of subadult red drum, Sciaenops ocellatus, fed either a diet of 440 or 360 g protein kg,1 diet (44% or 36%) with varying E:P ratios were tested. In the first experiment, five diets containing 440 g protein kg,1 diet and one diet containing 360 g protein kg,1 diet (reference) were offered to red drum (mean initial weight of 186 g). The five test diets contained 83, 103, 123, 143, and 163 g lipid kg,1 diet, resulting in E:P ratios ranging from 34.3 to 38.9 kJ g protein,1. In experiment 2, five diets providing 360 g protein kg,1 diet and one diet containing 440 g protein kg,1 diet (reference) were offered to red drum (mean initial weight of 145 g). Dietary lipid levels included 83, 123, and 163 g lipid kg,1 diet, and dietary carbohydrate was diluted with 10% and 20% non-nutritive bulk filler in two of the diets to result in E:P ratios ranging from 34.5 to 46.7 kJ g protein,1. In experiment 1, no significant differences in mean final weight, mean weight gain, feed efficiency, protein conversion efficiency or hepatosomatic index were observed between the five test diets providing 440 g protein kg,1 diet. Intraperitoneal fat generally increased with increasing dietary lipid. The results of experiment 2 indicate that amongst the test diets with 360 g protein kg,1 diet, mean final weight, mean weight gain, feed efficiency, protein conversion efficiency and hepatosomatic index were not significantly different. Intraperitoneal fat significantly increased with increasing dietary lipid. In both experiments, fish offered diets with 440 g protein kg,1 diet produced significantly higher growth and FE values as compared to fish receiving diets containing 360 g protein kg,1 diet. This study indicated that subadult red drum are tolerant of shifts in E:P ratios and utilize a wide range of dietary lipid and carbohydrate without compromising growth. [source]


    Dietary protein/lipid level and protein source effects on growth, tissue composition and lipid metabolism of blackspot seabream (Pagellus bogaraveo)

    AQUACULTURE NUTRITION, Issue 2 2010
    A.C. FIGUEIREDO-SILVA
    Abstract A study was carried out to determine the effects of fish meal (FM) replacement by plant protein (PP) on growth, body composition and lipid metabolism of blackspot seabream fed different protein/lipid levels. Four experimental diets were formulated to contain two protein (P) and lipid (L) levels (60P/6L or 50P/10L), varying in their protein source (100% FM or 50% FM: 50% PP). Dietary inclusion of PP did not affect growth of fish fed 60P/6L, although fish fed 50P/10L exhibited lower final body weight and daily growth index. Fish fed 60P/6L presented the highest protein and the lowest lipid content. FM replacement by PP has decreased muscle n-3 whereas the n-6 fatty acids increased. Glucose-6-phosphate dehydrogenase and fatty acid synthetase (FAS) were depressed in fish fed 50P/10L. FAS was significantly increased with 60P/6L PP which was positively correlated with lipid retention data. Those results suggest the conversion of other nutrient than lipid (protein and/or carbohydrates) into corporal fat. Hepatic lipoprotein lipase activity was lowest in fish fed PP diets. Plasma glucose peaked 1,2 h postfeeding, in all groups and was generally higher with 60P/6L FM. This work shown that besides dietary P/L level, protein source has a strong effect on species lipogenesis and lipid retention. Hence, the 50P/10L FM diet was the most cost-effective for blackspot seabream juveniles. [source]


    Dietary Lipid Utilization by Juvenile Summer Flounder Paralichthys dentatus

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2003
    T. Gibson Gaylord
    The ability of juvenile summer flounder Paralichthys dentatus to utilize dietary lipid as energy, and the effect of dietary lipid on weight gain and body composition was investigated in a 12-week feeding trial. Diets were formulated to provide 55% crude protein from herring meal and casein. Menhaden oil was added to produce diets with 8, 12, 16 or 20% total lipid while providing 16.0 kJ available energy/g dry diet. The diet containing 20% total lipid supplied 16.7 kJ available energy/g dry diet due to the high levels of protein and lipid. An additional diet was included to reproduce currently available commercial diet formulations for flounder, providing 55% crude protein supplied solely from herring meal and 16% total dietary lipid. Juvenile summer flounder (initial weight 23 g) were stocked into triplicate aquaria in a closed, recirculating system maintained at 20 C. Fish were fed 2% of body weight each day divided into two equal feedings. Upon termination of the study, effects of dietary lipid on weight gain, body condition indices, and proximate composition were determined. Weight gain (96,149% of initial weight), feed efficiency ratio values (0.43,0.48). fillet yield, and whole-body composition all were unaffected by dietary lipid level. High levels of dietary lipid did increase the lipid content in the finray muscle, as fish fed diets containing 16 and 20% dietary lipid had significantly higher lipid levels than fish fed the diet containing 8% lipid. No apparent protein sparing effect of lipid was observed. These data indicate that currently available commercial feeds for summer flounder may be over-formulated and show a need for further research to determine specific and accurate nutritional information for this species. [source]


    Influence of dietary lipid/protein ratio on survival, growth, body indices and digestive lipase activity in Snakehead (Channa striatus, Bloch 1793) fry reared in re-circulating water system

    AQUACULTURE NUTRITION, Issue 5 2010
    M. ALIYU-PAIKO
    Abstract Nine isoenergetic (18.5 kJ g,1) diets were formulated in a 3 3 factorial design to contain three protein levels (350, 400 and 450 g kg,1) for each of three lipid levels (65, 90 and 115 g kg,1), respectively, and fed twice daily for 8 weeks to fish of mean initial weight 3.34 0.02 g reared in a re-circulatory water system. Temperature, pH and dissolved oxygen (DO) were maintained within the range 28,30 C, 5.6,6.8 and 4.82,6.65 mg L,1 respectively throughout. Results show that fish survival was better in the groups fed 65 g kg,1 lipid while growth performance (% weight gain, WG; specific growth rate, SGR) and nutrient utilization (feed conversion ratio, FCR; protein efficiency ratio, PER; protein intake, PI) in the 65/450 and 90/450 g kg,1 treatments were similar and significantly (P < 0.05) higher than in fish fed the other lipid/protein ratio combinations. The body indices monitored (Hepatosomatic index, HSI and viscerosomatic index, VSI) were similar among the treatments whereas intestinal lipase activity was not significantly (P < 0.05) affected by increase in dietary lipid and protein levels. Carcass composition showed that dietary protein level affected body protein content positively in the 65 and 90 g kg,1 lipid treatments, but dietary lipid level did not affect body lipid content. A lipid/protein ratio of 65/450 g kg,1 is considered adequate for good growth performance and survival of Channa striatus fry. [source]


    Effects of dietary protein and lipid levels on growth and energy productive value of pacific white shrimp, Litopenaeus vannamei, at different salinities

    AQUACULTURE NUTRITION, Issue 4 2010
    X.Z. ZHU
    Abstract A 8-week feeding experiment was conducted to evaluate the effect of different dietary protein and lipid levels on growth and energy productive value of juvenile Litopenaeus vannamei, at 30 and 2 ppt, respectively. Nine practical diets were formulated to contain three protein levels (380, 410 and 440 g kg,1) and three lipid levels (60, 80 and 100 g kg,1). Each diet was randomly fed to triplicate groups of 30 shrimps per tank (260 L). The effects of salinity and an interaction between dietary protein level and lipid level on growth and energy productive value of shrimp were observed under the experimental conditions of this study. At 30 ppt seawater, shrimp fed with 440 g kg,1protein diets had significantly higher weight gain (WG) than those fed with 380 g kg,1 protein diets at the same dietary lipid level, and the 60 g kg,1 lipid group showed higher growth than 80 g kg,1and 100 g kg,1 lipid groups at the same dietary protein level. At 2 ppt seawater, the growth of shrimp was little affected by dietary protein treatments when shrimp fed the 80 and 100 g kg,1 lipid, shrimp fed the 80 g kg,1 lipid diets had only slightly higher growth than that fed 60and 100 g kg,1 lipid diets when fed 380 and 410 g kg,1 dietary protein diets. A significant effect of salinity on growth of shrimp was detected with the growth responses at 30 ppt > 2ppt (P < 0.05). Final body lipid content, body protein content and energy productive value of shrimp was significantly higher in animals exposed to 30 ppt than in shrimp held at 2 ppt. [source]


    Effects of dietary protein to energy ratios on growth and body composition of juvenile Chinese sucker, Myxocyprinus asiaticus

    AQUACULTURE NUTRITION, Issue 2 2010
    Y.C. YUAN
    Abstract A growth experiment was conducted to investigate effect of dietary protein to energy ratios on growth and body composition of juvenile Myxocyprinus asiaticus (initial mean weight: 10.04 0.53 g, mean SD). Nine practical diets were formulated to contain three protein levels (340, 390 and 440 g kg,1), each with three lipid levels (60, 100 and 140 g kg,1), in order to produce a range of P/E ratios (from 22.4 to 32.8 mg protein kJ,1). Each diet was randomly assigned to triplicate groups of 20 fish in 400-L indoors flow-through circular fibre glass tanks provided with sand-filtered aerated freshwater. The results showed that the growth was significantly affected by dietary P/E ratio (P < 0.05). Fish fed the diets with 440 g kg,1 protein (100 and 140 g kg,1 lipid, P/E ratio of 31.43 and 29.22 mg protein kJ,1) had the highest specific growth rates (SGR) (2.16 and 2.27% day,1, respectively). However, fish fed the diet with 390 g kg,1 protein and 140 g kg,1 lipid showed comparable growth (2.01% day,1), and had higher protein efficiency ratio (PER), protein productive value (PPV) and energy retention (ER) than other groups (P < 0.05). No significant differences in survival were found among dietary treatments. Carcass lipid content was positively correlated with dietary lipid level, but irrespective of protein level and inversely correlated with carcass moisture content. Carcass protein contents increased with increasing dietary lipid at each protein level. The white muscle and liver composition showed that lipid increased with increasing dietary lipid level (P < 0.05). Dietary protein concentrations had significant effect on condition factor (CF), hepatosomatic index (HSI) and viscerosomatic index (VSI) (P < 0.05). However, dietary lipid concentrations had no significant effect on CF, HSI (P > 0.05). Based on these observations, 440 g kg,1 protein with lipid from 100 to 140 g kg,1 (P/E ratio of 29.22 to 31.43 mg protein kJ,1) seemed to meet minimum requirement for optimal growth and feed utilization, and lipid could cause protein-sparing effect in diets for juvenile Chinese sucker. [source]


    Growth and body composition of juvenile white shrimp, Litopenaeus vannamei, fed different ratios of dietary protein to energy

    AQUACULTURE NUTRITION, Issue 6 2008
    Y. HU
    Abstract A 10-week feeding experiment was conducted to evaluate the effect of different protein to energy ratios on growth and body composition of juvenile Litopenaeus vannamei (initial average weight of 0.09 0.002 g, mean SE). Twelve practical test diets were formulated to contain four protein levels (300, 340, 380 and 420 g kg,1) and three lipid levels (50, 75 and 100 g kg,1). Each diet was randomly fed to triplicate groups of 30 shrimps per tank (260 L). The water temperature was 28.5 2 C and the salinity was 28 1 g L,1 during the experimental period. The results showed that the growth was significantly (P < 0.05) affected by dietary treatments. Shrimps fed the diets containing 300 g kg,1 protein showed the poorest growth. However, shrimp fed the 75 g kg,1 lipid diets had only slightly higher growth than that fed 50 g kg,1 lipid diets at the same dietary protein level, and even a little decline in growth with the further increase of dietary lipid to 100 g kg,1. Shrimp fed the diet with 420 g kg,1protein and 75 g kg,1 lipid had the highest specific growth rate. However, shrimp fed the diet with 340 g kg,1 protein and 75 g kg,1 lipid showed comparable growth, and had the highest protein efficiency ratio, energy retention and feed efficiency ratio among dietary treatments. Triglycerides and total cholesterol in the serum of shrimp increased with increasing dietary lipid level at the same dietary protein level. Body lipid and energy increased with increasing dietary lipid level irrespective of dietary protein. Results of the present study showed that the diet containing 340 g kg,1 protein and 75 g kg,1 lipid with digestible protein/digestible energy of 21.1 mg kJ,1 is optimum for L. vannamei, and the increase of dietary lipid level has not efficient protein-sparing effect. [source]


    Interacting effects of dietary lipid level and temperature on growth, body composition and fatty acid profile of rohu, Labeo rohita (Hamilton)

    AQUACULTURE NUTRITION, Issue 6 2004
    K. Mishra
    Abstract Three isonitrogenous (320 g kg,1 crude protein, casein and gelatine) semi-purified diets with 80 (L8), 130 (L13) and 180 (L18) g kg,1 lipid (sunflower oil at increasing levels and cod liver oil fixed at 50 g kg,1) at three digestible energy levels (12 096, 13 986 and 15 876 kJ kg,1 dry weight) and were tested, in triplicate, on rohu fingerlings (3.2 0.08 g) at two different temperatures (21 and 32 C). Fish were fed to apparent satiation, twice daily, at 09.00 and 15.00 h, 7 days a week for 56 days. Maximum growth was obtained at a lipid level of 80 g kg,1 (L8) at 21 C (439.37%) and 130 g kg,1 (L13) at 32 C (481.8%). In general growth rate was higher at 32 C than at 21 C at all lipid levels. Tissue monounsaturated fatty acid (MUFA) contents decreased with increasing lipid level at 32 C, but the reverse occurred at 21 C. At 21 C, Polyunsaturated fatty acid (PUFA) level increased significantly (P > 0.05) over initial values, but was affected insignificantly by dietary lipid level. At 32 C, fish fed diet L13 had more n-3 fatty acid (FA) in liver and muscle than the other two dietary groups while at 21 C, both liver and muscle FA profiles exhibited significant change (P > 0.05) in n-3 and n-6 FA content which corresponded to variation in percent addition of dietary lipid. However, n-3/n-6 ratio was higher for fish fed diet L13 at 32 C and diet L8 at 21 C and may be correlated with fish growth. [source]


    Manipulation of end-product quality of rainbow trout with finishing diets

    AQUACULTURE NUTRITION, Issue 1 2000
    Rasmussen
    The effect of dietary lipid level upon various quality parameters of smoked rainbow trout were examined. Fish were fed four experimental diets differing in lipid content (18.8,31.4%). Groups received either a lipid-rich diet throughout the trial (101 days), a lipid-rich feed for 46 days followed by a lower fat diet for 55 days and vice versa, or a low fat diet throughout. A fifth group (controls), consisting of commercially reared animals, was employed for comparative purposes. The visceral fraction of experimental fish increased with increasing lipid ingestion, whereas final process yield decreased. Chemical analyses following salting and hot-smoking revealed that fillet lipid and ash was higher (P < 0.05) and moisture lower (P < 0.05) for fish fed the high-lipid diet throughout and during the last 55 days of trial. No differences were recorded with respect to sensory attributes between treatment groups, although differences were observed between tank-reared and control fish. In experimental animals, fillet protein content was negatively correlated with juiciness and fibreness, while dry matter was correlated with juiciness, fresh oily taste and rose flesh colour. The present study indicates that high lipid feeds can be employed without negatively influencing sensory characteristics or yield provided that lean finishing diets are fed prior to slaughter. Fasting of fish for 61 days improved slaughter yields without affecting relative yields among dietary groups. [source]


    Effect of dietary lipid level on the growth performance, feed utilization, body composition and blood chemistry of juvenile starry flounder (Platichthys stellatus)

    AQUACULTURE RESEARCH, Issue 10 2010
    Liyun Ding
    Abstract A study was conducted to determine the effect of dietary lipid level on the growth performance, feed utilization, body composition and blood chemistry of juvenile starry flounder. Five isonitrogenous diets with increasing dietary lipid levels (6%, 10%, 14%, 18% and 22% dry material) were each fed to triplicate groups of starry flounder (29.9 g) for 8 weeks. Weight gain (WG) and specific growth rate of fish fed the 6% lipid diet were significantly lower than the other groups, while there was no significant difference in fish fed the 10%, 14%, 18% and 22% lipid diets. Body lipid content increased with increasing dietary lipid levels. The moisture content of the whole body was negatively correlated to the dietary lipid level. The dietary lipid level also affected the lipid content of the dorsal muscle positively. Liver lipid content increased as the dietary lipid level increased from 6% to 14% and then decreased. With increasing dietary lipid level, the nitrogen retention achieved the highest value when the fish were fed the 14% lipid diet, but there were no significant differences with the 10% and 22% groups. The plasma total protein content first showed an increasing and then a decreasing trend with increasing dietary lipid level, and it was significantly higher in the 14% lipid group than other groups. Based on the WG response using the broken-line model, the optimum dietary lipid level for juvenile starry flounder was estimated to be 10.62% in the experiment. [source]


    Effects of dietary lipid levels on the growth, digestive enzyme, feed utilization and fatty acid composition of Japanese sea bass (Lateolabrax japonicus L.) reared in freshwater

    AQUACULTURE RESEARCH, Issue 2 2010
    Gang Luo
    Abstract Triplicate groups of 40 Japanese sea bass Lateolabrax japonicus reared in freshwater (average weight, 9.520.47 g) were fed with six isonitrogenous (,46% crude protein) diets containing 6%, 8%, 10%, 12%, 14% or 16% lipid for 10 weeks respectively. The results showed that the maximum weight gain (WG), specific growth rate (SGR), feed intake (FI) and protein efficiency ratio (PER) all occurred at the 10% lipid level (P<0.05) and growth depression occurred when the dietary lipid level was over 12%. Whole body and liver lipid concentrations were enhanced with the increase in the dietary lipid levels, but the muscle lipid content did not significantly change with the increase in the dietary lipid levels. Both liver pepsin and trypsin activities increased with dietary lipid levels ranging from 6% to 10%, and then decreased with a further increase in the dietary lipid content. Liver lipase activities showed a positive correlation with dietary lipid levels, but amylase activities were not markedly influenced by dietary lipid levels. High proportions of 18:1n-9, 20:1n-9, eicosapentaenoic acid (20:5n-3; EPA), 22:1n-11 and docosahexaenoic acid (22:6n-3; DHA), and low concentrations of n-6 fatty acids, particularly 18:2n-6 occurring in the liver and muscle, to some extent, reflected the fatty acid composition in experimental diets. [source]


    Effects of dietary protein and lipid content on growth performance and biological indices of iridescent Shark (Pangasius hypophthalmus, Sauvage 1878) fry

    AQUACULTURE RESEARCH, Issue 4 2009
    Preeda Phumee
    Abstract Dietary protein and lipid effects on growth, body composition and indices of iridescent Shark Pangasius hypophthalmus (Sauvage 1878) fry were studied using a 4 2 factorial design. Triplicate groups of 10 fish per tank, with initial mean weights of 3.54,3.85 g were fed eight isocaloric diets comprising a combination of four protein levels (250, 300, 350 and 400 g kg,1 or 25%, 30%, 35% and 40%) and two lipid levels (60 and 120 g kg,1 or 6% and 12%) respectively. The fish were hand-fed to satiety twice daily for 8 weeks. Specific growth rate (SGR) and feed conversion ratio (FCR) showed significant effects (P<0.05) with variations in dietary protein and lipid. The highest SGR was observed in fish fed 40% protein/12% lipid diet but this value was not significantly (P>0.05) different from the fish fed 30% protein/12% lipid diet. The FCR was lowest for the 40/12 diet and differed significantly only with the 25/6, 25/12 and 30/6 treatments respectively. The hepatosomatic index (HSI) was significantly affected by the level of protein, but intraperitoneal fat (IPF) showed significant variation due to dietary lipid level. The HSI significantly (P<0.05) decreased when dietary protein increased from 25% to 30% but increased marginally thereafter. The IPF values increased with increased dietary lipid but decreased with increased dietary protein. Body protein was positively correlated with dietary protein content; conversely, body lipid content decreased with increase in dietary protein. The results of this experiment indicate the presence of a protein-sparing effect of lipid as fish fed 30% protein/12% lipid diet had growth and feed utilization comparable to those fed 40% protein/12% lipid diet. [source]


    Effects of dietary lipid level on liver and muscle lipid deposition in juvenile haddock, Melanogrammus aeglefinus L.

    AQUACULTURE RESEARCH, Issue 2001
    D A Nanton
    Abstract The effects of dietary lipid levels on growth, feed utilization, hepatosomatic index (HSI), liver lipid deposition and tissue fatty acid composition in haddock were investigated. Triplicate tanks of juvenile haddock (6.9 g) were fed graded levels of herring oil to supply 14, 16, 19 and 22% lipid (DM, dry matter) in fish meal-based, isonitrogenous diets. Growth and feed conversion ratio of juvenile haddock was not significantly (P < 0.05) affected by increasing the lipid content of the diet. A significant increase in HSI (9.8,12.1%), total liver lipid (63.2,69.0%) and whole body gross energy content (6.03,6.39 kcal g,1 DM) were observed in haddock fed 14% vs. 22% lipid. Although the HSI of these cultured haddock was high in comparison to wild gadoids, histological analyses of these haddock livers did not reveal any overt pathology. Muscle lipid levels (1.0%) did not increase significantly with dietary lipid. Liver fatty acid levels mirrored dietary fatty acid (FA) composition. The muscle consisted mainly of polar lipid (84.3 2.5% of total lipid) and a large proportion (52.6 0.8%) of polyunsaturated FA. A dietary lipid level of 14% DM or less is recommended for juvenile haddock. [source]


    Effects of Dietary Lipids on Growth and Feed Utilization of Jade Perch, Scortum barcoo

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2009
    Li Ping Song
    To examine the effects of dietary lipids on the growth and feed utilization of jade perch juveniles, Scortum barcoo, diets containing 36.3% crude protein supplemented with increasing lipid levels (6, 9, 12, and 15% of the dry matter) were used to feed triplicate groups of 30 fish for 60 d. At the end of the experiment, more than 95% fish survived well from all diet groups (P > 0.05). Measurements on the weight gains and the daily specific growth rates indicated that fish fed with diets of 12 and 15% lipids exhibited higher growth rates (P < 0.05); evaluations for the feed conversion ratio and the protein efficiency ratio indicated that fish fed with 12 and 15% lipid diets used their feed and dietary proteins more efficiently (P < 0.05). The muscle lipid and dry matter contents increased dramatically in fish fed with higher dietary lipid levels (P < 0.05). The highest lipid contents were obtained from fish in the 15% lipid diet group and the highest amount of dry matters from the 12% lipid diet group. On the other hand, protein contents in fish muscles declined with increasing dietary lipid levels (P < 0.05), and the lowest values were shown in the 15% lipid diet group. Ash contents showed no significant differences from muscles of fish fed with four different diets (P > 0.05). Together, increasing lipid levels in fish diets was effective to improve fish growth, feed efficiency, and protein utilization. [source]


    Dietary Lipid Utilization by White Sea Bream (Diplodus sargus) Juveniles

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2008
    R. S
    Six experimental diets were formulated to be isoproteic (45% protein) and to contain from 9 to 24% dietary lipid levels (dry matter basis). Fish meal and fish oil were used as the main protein and lipid sources, respectively. At the end of the trial, there were no significant differences (P > 0.05) among groups in fish performance or in whole-body composition. From the results of this trial, it is concluded that, within the range of values tested, increasing dietary lipid levels above 9% has no advantage as it does not promote growth or spare protein for growth purposes. [source]


    Effect of dietary lipid level on the growth performance, feed utilization, body composition and blood chemistry of juvenile starry flounder (Platichthys stellatus)

    AQUACULTURE RESEARCH, Issue 10 2010
    Liyun Ding
    Abstract A study was conducted to determine the effect of dietary lipid level on the growth performance, feed utilization, body composition and blood chemistry of juvenile starry flounder. Five isonitrogenous diets with increasing dietary lipid levels (6%, 10%, 14%, 18% and 22% dry material) were each fed to triplicate groups of starry flounder (29.9 g) for 8 weeks. Weight gain (WG) and specific growth rate of fish fed the 6% lipid diet were significantly lower than the other groups, while there was no significant difference in fish fed the 10%, 14%, 18% and 22% lipid diets. Body lipid content increased with increasing dietary lipid levels. The moisture content of the whole body was negatively correlated to the dietary lipid level. The dietary lipid level also affected the lipid content of the dorsal muscle positively. Liver lipid content increased as the dietary lipid level increased from 6% to 14% and then decreased. With increasing dietary lipid level, the nitrogen retention achieved the highest value when the fish were fed the 14% lipid diet, but there were no significant differences with the 10% and 22% groups. The plasma total protein content first showed an increasing and then a decreasing trend with increasing dietary lipid level, and it was significantly higher in the 14% lipid group than other groups. Based on the WG response using the broken-line model, the optimum dietary lipid level for juvenile starry flounder was estimated to be 10.62% in the experiment. [source]


    Growth, feed utilization and body composition of African bonytongue, Heterotis niloticus, fingerlings fed diets containing various protein and lipid levels

    AQUACULTURE RESEARCH, Issue 10 2010
    Serge-Eric Monentcham
    Abstract In order to evaluate the effects of dietary protein and lipid levels on the growth, feed utilization and body composition of Heterotis niloticus fingerlings, a factorial experiment with three replicates was conducted. Six experimental diets containing three crude protein levels (28%, 32% and 36%) and two crude lipid levels (6% and 13%) were tested. Heterotis niloticus (2.34 g) were fed with the diets to apparent satiation, twice a day. For 56 days, weight gain (WG), specific growth rate (SGR), feed efficiency (FE) and protein retention (PR) were significantly affected by dietary protein and dietary lipid levels respectively (P<0.01). The highest WG, SGR and FE were observed for fingerlings fed the diet containing 36% protein and 6% lipid, but no significance difference was found between groups fed with the following diets: P28L13 (28% protein and 13% lipid), P32L6, P32L13 and P36L13. A significant interaction between dietary protein and lipid was observed for WG, SGR, FE and PR. The whole-body protein, lipid, moisture and ash content were not significantly affected by dietary lipid levels, but body protein and lipid content were significantly affected by dietary protein. The dietary protein-sparing effect was clearly demonstrated when the dietary energy of lipid increased from 17 to 19.6 kJ g,1 at 28% crude protein on H. niloticus. [source]


    Effects of dietary lipid levels on the growth, digestive enzyme, feed utilization and fatty acid composition of Japanese sea bass (Lateolabrax japonicus L.) reared in freshwater

    AQUACULTURE RESEARCH, Issue 2 2010
    Gang Luo
    Abstract Triplicate groups of 40 Japanese sea bass Lateolabrax japonicus reared in freshwater (average weight, 9.520.47 g) were fed with six isonitrogenous (,46% crude protein) diets containing 6%, 8%, 10%, 12%, 14% or 16% lipid for 10 weeks respectively. The results showed that the maximum weight gain (WG), specific growth rate (SGR), feed intake (FI) and protein efficiency ratio (PER) all occurred at the 10% lipid level (P<0.05) and growth depression occurred when the dietary lipid level was over 12%. Whole body and liver lipid concentrations were enhanced with the increase in the dietary lipid levels, but the muscle lipid content did not significantly change with the increase in the dietary lipid levels. Both liver pepsin and trypsin activities increased with dietary lipid levels ranging from 6% to 10%, and then decreased with a further increase in the dietary lipid content. Liver lipase activities showed a positive correlation with dietary lipid levels, but amylase activities were not markedly influenced by dietary lipid levels. High proportions of 18:1n-9, 20:1n-9, eicosapentaenoic acid (20:5n-3; EPA), 22:1n-11 and docosahexaenoic acid (22:6n-3; DHA), and low concentrations of n-6 fatty acids, particularly 18:2n-6 occurring in the liver and muscle, to some extent, reflected the fatty acid composition in experimental diets. [source]


    Effects of dietary protein and lipid levels on growth performance and body composition of black sea bass Centropristis striata (Linnaeus 1758) during grow-out in a pilot-scale marine recirculating system

    AQUACULTURE RESEARCH, Issue 4 2009
    Md Shah Alam
    Abstract The influence of four formulated practical diets, with different protein and lipid levels, on the growth and body composition of black sea bass (Centropristis striata L.) pre-adults was evaluated in a pilot-scale marine recirculating system. Four test diets were prepared with a combination of two protein levels (44% and 54%) and two lipid levels (10% and 15%). The diets were as follows: low protein and low lipid (LP:LL; 44:10), low protein and high lipid (LP:HL; 44:15), high protein and low lipid (HP:LL; 54:10) and high protein and high lipid (HP:HL; 54:15). Fish (mean weight=75.5 g) were fed the respective diets for 90 days. For fish fed LP:HL, body weight gain was significantly (P<0.05) higher than fish fed LP:LL. Increasing the protein level from 44% to 54% did not produce a significant effect on weight gain at high lipid level. A significant (P<0.01) interactive effect between dietary protein and lipid levels on the growth and feed utilization was observed. Total lipid content in the whole body, muscle and liver was significantly affected by the dietary lipid levels. The results suggested that a combination of 44% dietary protein and 15% lipid was optimal for the growth of black sea bass. [source]


    Reproductive performance, lipids and fatty acids of mud crab Scylla serrata (Forsskl) fed dietary lipid levels

    AQUACULTURE RESEARCH, Issue 14 2007
    Veronica R Alava
    Abstract Natural food (NF, control), artificial diets (AD) containing total lipid levels of 10%, 12% and 14% (AD10, AD12 and AD14) and their combinations (AD10+NF, AD12+NF and AD14+NF) were fed for 112 days to pond-sourced eyestalk-ablated mud crab Scylla serrata (6256.4 g) in tanks in order to determine their effects on reproduction and lipid profiles in broodstock tissues and zoeae. Crabs fed NF had the highest number of spawning followed by crabs fed AD10+NF and AD14+NF. Higher offspring production (number of zoeae) was obtained from crabs fed NF and AD+NF than from AD. As dietary total lipid levels increased, total lipid of broodstock ovaries, hepatopancreas, muscle and zoeae correspondingly increased in which AD+NF promoted higher levels than AD. Increased dietary total lipid levels enhanced lipid classes such as triacylglycerols and phosphatidyl choline levels in zoeae, all higher in crabs fed AD+NF than in AD. The major fatty acids in zoeae, particularly 16:0, 18:0, 18:1n-9 and 20:4n-6, 20:5n-3 and 22:6n-3, were higher in crabs fed AD+NF than in AD, the contents corresponding to broodstock dietary total lipid levels. A 10% total lipid in AD in combination with NF was sufficient to provide the essential lipids in crabs in the improvement of larval production and quality. [source]


    Effects of dietary lipid level on liver and muscle lipid deposition in juvenile haddock, Melanogrammus aeglefinus L.

    AQUACULTURE RESEARCH, Issue 2001
    D A Nanton
    Abstract The effects of dietary lipid levels on growth, feed utilization, hepatosomatic index (HSI), liver lipid deposition and tissue fatty acid composition in haddock were investigated. Triplicate tanks of juvenile haddock (6.9 g) were fed graded levels of herring oil to supply 14, 16, 19 and 22% lipid (DM, dry matter) in fish meal-based, isonitrogenous diets. Growth and feed conversion ratio of juvenile haddock was not significantly (P < 0.05) affected by increasing the lipid content of the diet. A significant increase in HSI (9.8,12.1%), total liver lipid (63.2,69.0%) and whole body gross energy content (6.03,6.39 kcal g,1 DM) were observed in haddock fed 14% vs. 22% lipid. Although the HSI of these cultured haddock was high in comparison to wild gadoids, histological analyses of these haddock livers did not reveal any overt pathology. Muscle lipid levels (1.0%) did not increase significantly with dietary lipid. Liver fatty acid levels mirrored dietary fatty acid (FA) composition. The muscle consisted mainly of polar lipid (84.3 2.5% of total lipid) and a large proportion (52.6 0.8%) of polyunsaturated FA. A dietary lipid level of 14% DM or less is recommended for juvenile haddock. [source]


    Protein lipid ratio for the growth and survival of juvenile crayfish Procambarus acanthophorus (Hobbs 1972) reared under controlled conditions

    AQUACULTURE RESEARCH, Issue 9 2010
    Enrique Cervantes-Santiago
    Abstract The influence of dietary protein/lipid levels on growth and survival in juvenile crayfish (Procambarus acanthophorus) was evaluated during a 12-week nutritional trial. Twenty experimental diets were formulated containing different protein (200, 250, 300, 350 and 400 g kg,1) and lipid (60, 80, 100 and 120 g kg,1) levels. A bifactorial model (5 4) was used with three replicates and 15 crayfish (0.0140.006 g) per replicate, in a recirculation system with 60,15 L rectangular tanks and a biological filter, the culture conditions were a photoperiod of 12:12 h L:D and temperature 24.71.0 C. Total survival ranged from 66.6% to 86.6%, with no differences attributed to treatments. Dietary protein levels had a significant effect on growth gain and nutritional efficiency; in contrast, lipid levels had no effect on juvenile performance. The 250/120 (protein/lipid) treatment promoted the most efficient growth (final weight: 3.09 g, weight gain: 21 995%, specific growth rate: 3.35% day,1); the less efficient growth was observed in juveniles fed with 400 g kg,1 protein diets. The quadratic regression model indicated 279 g kg,1 as the optimal protein level for crayfish growth, while levels between 211 and 232 g kg,1 could minimize the feeding costs without affecting growth. [source]