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Dietary Lipid (dietary + lipid)

Distribution by Scientific Domains

Earth and Environmental Science	86%
Medical Sciences	10%

Terms modified by Dietary Lipid

dietary lipid level

dietary lipid source

Selected Abstracts

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]

Preliminary investigations on the effects of dietary lipid on the spawning performance and egg quality of black sea bass Centropristis striata L

AQUACULTURE RESEARCH, Issue 16 2009
Christopher D Bentley
Abstract Adult black sea bass Centropristis striata broodstock (N=162) were fed three different dietary treatments: two commercially prepared diets with 45% protein and two different lipid levels (12% and 20%) (diets 1 and 2), and a diet of frozen Atlantic silversides Menidia menidia (SS, diet 3). Broodstock were held under controlled photothermal conditions and induced to spawn with an LHRHa pellet (72 ,g kg,1 bw). Dietary lipid had pronounced effects on spawning performance and egg quality. Diet 3 (SS) produced a significantly (P<0.05) higher fertilization success (22.4%) than diets 1 (0.6%) and 2 (4.8%). The hatching success of fertilized eggs was similar in all diets (range=40,58.6%), but only two spawns from diet 1 (12% lipid) yielded viable yolk-sac larvae (YSL). Diet 3 (SS) also produced significantly more YSL per female (21.8 × 103) than the diet 1 (0.3 × 103). Eggs from diet 3 (SS) contained a significantly greater proportion of n-3 series fatty acids, with docosahexaenoic acid (DHA) as the largest fraction. Eggs from commercially prepared dietary treatments contained significantly more n-6 fatty acids. The poor spawning performance of fish fed diet 1 (12% lipid) may be related to higher levels of linoleic acid and lower levels of DHA in the diet. [source]

The benefits of oestrogens on postprandial lipid metabolism are lost in post-menopausal women with Type 2 diabetes

DIABETIC MEDICINE, Issue 7 2006
M. G. Masding
Abstract Aims, Women with Type 2 diabetes appear to lose the protection against cardiovascular disease (CVD) afforded by oestrogens. We examined the effects of oestrogen hormone replacement therapy (HRT) on postprandial clearance of dietary fat in non-diabetic and diabetic post-menopausal women. Methods, In a cross-sectional study, fasting subjects [HRT+ and HRT, control and diabetic women; Type 2 diabetes (DM) HRT+n = 8, DM HRT,n = 14, control HRT+n = 7, control HRT,n = 11] consumed a meal containing the stable isotope 1,1,1,[13]C-tripalmitin, with blood and breath sampled for 6 and 24 h, respectively, in the postprandial period. Results, In diabetic women, there were no differences between the HRT+ and HRT, groups for any of these parameters. In contrast, in HRT+ compared with HRT, control women, the triglyceride (TG) area under the curve was lower [AUC; HRT+ median (range) 7.7 (4.1, 12.8) mmol/l per 6 h, HRT, 9.7 (3.9, 18.5) mmol/l per 6 h, P < 0.05] and [13]C-palmitic acid in the TG fraction was also lower [HRT+ 23.2 (10.3, 41.3) ng/ml per 6 h, HRT, 47.7 (12.6, 77.2) ng/ml per 6 h, P < 0.05], suggesting the lower postprandial triglyceridaemia associated with HRT in non-diabetic women is because of better chylomicron clearance. Conclusions, The oestrogen-associated advantage in clearance of dietary lipid we observed in non-diabetic post-menopausal women is not seen in post-menopausal diabetic women. This is likely to promote an atherogenic lipoprotein profile and may contribute to the loss of CVD protection seen in diabetic women. [source]

Growth performance and body composition of sub-yearling Persian sturgeon, (Acipenser persicus, Borodin, 1897), fed different dietary protein and lipid levels

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 3 2007
M. Mohseni
Summary In order to evaluate the protein and energy requirement of Persian sturgeon (Acipenser persicus) sub-yearlings, eight experimental diets containing two protein levels (40% and 45%) and four lipid levels (10%, 15%, 20% and 25%) were tested. Sturgeons (W0 = 136.8 g) were fed the experimental diets to satiation four times daily for 150 days, resulting in a final mean weight of 375.8 g. Growth was significantly affected by lipid content of the diets. At 40% protein level, weight gain and specific growth rate (% per day) were significantly improved (P < 0.05) by increasing the dietary lipid (energy) content. Protein efficiency ratio (PER) was significantly affected by different dietary treatments for each dietary protein level tested, reaching a mean value of 3.58 in fish fed high lipid diets and a PER of 2.77 in low lipid diets. Results obtained in the present study suggest that the optimum dietary protein content for Persian sturgeon is 40%, with an estimated optimum protein-to-energy ratio of 18,20 mg kJ,1. [source]

Influence of dietary composition on growth and energy reserves in tench (Tinca tinca)

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 1 2001
N. De Pedro
The effects of different protein, lipid and carbohydrate diets on growth and energy storage in tench, Tinca tinca L., were studied. Over a 2-month period fish were fed four different diets: control, protein-enriched, carbohydrate-enriched and lipid-enriched. The best growth rates were obtained with the control and protein-enriched diets; the carbohydrate diet produced the worst results (lowest specific growth rate, weight gain, nutritional index and hepatosomatic index). These results suggest that it is not advisable to reduce dietary fish protein below 35%, and that it is not possible to obtain a protein-sparing effect of either lipids or carbohydrates, at least in our experimental conditions. The high-protein diet resulted in the storage of energy excess as muscle proteins and hepatic glycogen. Tench fed the high-carbohydrate diet stored carbohydrates as muscle glycogen and reduced plasma triglycerides. Finally, both liver and muscle lipid content were in positive correlation to dietary lipid. [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]

Effects of Dietary Protein and Energy Levels on Growth and Body Composition of Juvenile Flounder Paralichthys olivaceus

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2000
Sang-Min Lee
A feeding trial of three protein levels (30, 40 and 50%) and two energy levels (300 and 400 kcal/100-g diet) factorial design with three replications was carried out to investigate the proper dietary protein and energy levels for the growth of juvenile flounder Paralichthys olivaceus. Weight gain of fish tended to improve with increasing dietary protein level. Weight gain of fish fed either the 40% or 50% protein diet with 300 kcal/100-g diet was significantly higher (P < 0.05) than with 400 kcal/100-g diet. The best weight gain was obtained from fish fed the 50% protein diet with 300 kcal/100-g diet. Feed efficiency tended to improve with increasing dietary protein level. However, dietary energy level had no significant effect on feed efficiency of fish fed the 30% or 50% protein diet, but that of fish fed the 40% protein diet with 300 kcal/100-g diet was significantly higher than with 400 kcal/100-g diet. Protein retention tended to increase as dietary protein level increased and energy level decreased. Lipid content of fish fed the diet containing 400 kcal/100-g diet was significantly higher than that of fish fed the diet containing 300 kcal/100-g diet at all protein levels. Fatty acid compositions such as linoleic acid, EPA (20:5n-3) and DHA (22:6n-3) offish were directly affected by dietary lipid (squid liver oil and/or soybean oil) used for energy source. Based on the above results, it can be concluded that the proper dietary protein and energy levels for the growth of juvenile flounder are 50% and 300 kcal/100-g diet, respectively. [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]

Effect of dietary carbohydrate-to-lipid ratios on growth performance, body composition, nutrient utilization and hepatic enzymes activities of herbivorous grass carp (Ctenopharyngodon idella)

AQUACULTURE NUTRITION, Issue 3 2010
W. GAO
Abstract Six isonitrogenous (390 g kg,1) and isoenergetic (16.2 kJ g,1) diets with varying carbohydrate : lipid (CHO : L) ratios (202.5,1.74), were fed to triplicate groups of 25 fish in indoor recirculation system. Over 8-week-growth trial, best weight gain (WG), specific growth rate, feed conversion ratio, protein efficiency ratio and protein production value (P < 0.05) were observed in fish-fed diets with CHO : L ratio of 7.5. Fish fed either the lowest (1.7) or highest (202.5) CHO : L ratio tended to produce lower (P < 0.05) growth and feed conversion efficiencies. The values of viscerosomatic index, hepatosomatic index and intraperitoneal fat ratio increased as dietary CHO : L ratios decreased. There were no significant differences in whole body and liver crude protein among dietary treatments. Whole body and liver lipid increased as CHO : L ratios decreased. Plasma cholesterol and triacylglyceride levels increased linearly as dietary CHO : L ratios decreased. Activities of glucokinase and pyruvate kinase were stimulated by elevated levels of dietary carbohydrate; however, activities of lipase (LPS) and alkaline phosphatase were stimulated by elevated levels of dietary lipid. Based on a second-order polynomial regression analysis of WG against dietary carbohydrate and lipid levels, 275 g kg,1 of carbohydrate and 59 g kg,1 of lipid, corresponding to a CHO : L ratio of 4.7, in a diet holding 390 g kg,1 of crude protein and 16.3 kJ g,1 of gross energy, proved to be optimal for grass carp. These results indicated that utilization of dietary lipid and carbohydrate was moderate in grass carp, but the fish were a little more capable of utilizing lipid compared with carbohydrate. [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]

Liver oil of pharaoh cuttlefish Sepia pharaonis Ehrenberg, 1831 as a lipid source in the feed of giant freshwater prawn, Macrobrachium rosenbergii (De Man 1879)

AQUACULTURE NUTRITION, Issue 3 2009
G. SHYLA
Abstract The efficacy of pharaoh cuttlefish (Sepia pharaonis Ehrenberg, 1831) liver lipid in the feed for juveniles of giant freshwater prawn Macrobrachium rosenbergii (De Man 1879) was tested by feeding five experimental diets prepared using clam meat, groundnut oil cake, wheat bran, tapioca powder, vitamin,mineral mixture and cellulose powder as the major ingredients. The test diets T1, T2, T3, T4 and T5, containing five levels (1, 2, 3, 4 and 5%, respectively) of lipid, extracted from the liver of pharaoh cuttlefish, were fed to 30-day-old prawn juveniles for 60 days, in triplicates and compared against a control. Analysis of variance of the growth parameters showed that the juveniles fed with T2, containing 2% cuttlefish liver lipid with a total lipid content of 9.85% and lipid,carbohydrate ratio of 1 : 3.8, showed significantly better growth (P < 0.05) with the highest weight gain of 118%, greatest food conversion and protein utilization efficiency, and the highest body protein content, although the survival rates remained unaffected among treatments. Growth of the juveniles, however, declined at lipid levels >2%. Addition of cuttlefish liver lipid led to an increase of ,-3 and ,-6 fatty acids in T2, the proportion of ,-6 being higher than the former. The crude lipid content of the body of test animals also increased with the increase in dietary lipid from 1.51% in T1 to 3.27% in T5. The present study indicates that cuttlefish liver lipid can be successfully used as a substitute for conventional lipid sources in rearing juveniles of giant freshwater prawn, an eco-friendly practice in recycling cuttlefish waste , a discarded fishery by-product. [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]

A multivariate approach to optimization of macronutrient composition in weaning diets for cod (Gadus morhua)

AQUACULTURE NUTRITION, Issue 1 2006
K. HAMRE
Abstract Atlantic cod, initial weight 0.26 g, were fed diets varying in added protein from 530 to 830 g kg,1, lipid from 50 to 300 g kg,1 and carbohydrate from 0 to 150 g kg,1 of dry weight, according to a three-component mixture design. Analysed values of protein and lipid were 500,770 g kg,1 and 30,270 g kg,1, respectively. Analysed carbohydrate levels were as added. Increasing levels of both lipid and carbohydrate had a positive effect on fish growth (P < 10,3), whereas protein levels above 600 g kg,1 gave a reduction in growth (P < 10,4). The effects on growth were evident in fish less than 4 g, whereas fish growth between 4 and 6 g was unaffected by the dietary variation. It is hypothesized that the reduction in growth at high protein levels in fish of less than 4 g could be owing to incomplete utilization of protein, as the stomach of cod is not fully developed before the fish is approximately 1 g. Mortality and cannibalism were high in fish less than 4 g but low when the fish grew from 4 to 6 g. There was a significant decrease in cannibalism with increasing dietary lipid during the first half of the experiment (P < 0.05) and cannibalism was consistently high in fish fed less than 150 g kg,1 lipid. The lipid level in whole fish increased with increasing dietary levels of lipid (P < 10,6) and carbohydrate (P < 10,4), whereas the liver lipid level increased with increasing dietary lipid up to 200 g kg,1 (P < 10,6) and decreased thereafter (P < 10,4). Whole body glycogen increased slightly with increasing levels of dietary carbohydrate (P < 0.05) and was not affected by the other dietary variables. Liver glycogen increased in response to increasing dietary carbohydrate (P < 10,5) and decreasing levels of dietary lipid (P < 10,5). An abrupt increase in liver glycogen was seen with the reduction in dietary lipid from 100 to 50 g kg,1. The hepatosomatic index increased in response to both dietary lipid and carbohydrate (P < 10,6). It is concluded that the protein requirement of young cod is less than 500 g kg,1 of dry diet. Fish of less than 4 g should not be given more than 620 g kg,1 protein and should be supplemented with 150,200 g kg,1 lipid. Carbohydrate up to 150 g kg,1 of dry diet promoted growth and did not seem to affect the fish negatively. Fish above 4 g can be given diets varying in protein and carbohydrate over the wide range of concentrations used in the present study, but lipid supplementation should be restricted to between 100 and 200 g kg,1. [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]

Evaluation of canola oils as alternative lipid resources in diets for juvenile red seabream, Pagrus auratus

AQUACULTURE NUTRITION, Issue 5 2003
B. Glencross
Abstract This study examined three potential oil resources, crude and refined canola oil and refined soybean oil as replacements for added dietary fish oil in diets for juvenile red seabream. These oil resources were evaluated for their potential to replace added fish oil (40 g kg,1) in fishmeal based (600 g kg,1) diets, with 100 g kg,1 of total lipids. Each of the three plant oils was used to replace 25%, 50%, 75% or 100% of the added dietary fish oil. Each of the three plant oils showed potential as a replacement for dietary fish oil, although a significant reduction in growth and feed utilisation was observed with the complete (100%) replacement of added fish oil by crude canola oil. No other significant effects of oil type or inclusion level on growth were apparent. A negative control (no added fish oil or plant oil, 60 g kg,1 of total lipid) yielded poorer growth than all treatments except the diet containing 40 g kg,1 of added crude canola oil (100% replacement). This observation confirmed that the added oils were utilized by the fish. A positive control diet containing 80 g kg,1 of added fish oil (140 g kg,1 total dietary lipid) sustained the best growth in the study, confirming that the 13 experimental diets were energy limiting as planned. Notably, few effects of the alternative oils were seen on the proximate composition of the fish. However, the influence of the alternative oils on the tissue fatty acid composition was considerable, irrespective of plant oil type or processing grade. Particularly notable was the overall increase in the level of polyunsaturated fatty acids in the tissues of the fish fed the plant oil diets, with these trends becoming more apparent with the greater levels of fish oil replacement. Minimal reductions in the levels of the long-chain polyunsaturated fatty acids of eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) acid were observed from any of the plant oil treatments. Sensory assessment, by an Australian taste panel, of the fish fed the fish oil reference, or the 100% replacement by refined canola or refined soybean diets showed a preference in order of canola oil > soybean oil > fish oil fed fish. Clearly, both canola and soybean oils have considerable potential as replacements of fish oils in diets for this species. [source]

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]

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]

Influence of different sources and levels of dietary protein and lipid on the growth, feed efficiency, muscle composition and fatty acid profile of Snakehead Channa striatus (Bloch, 1793) fingerling

AQUACULTURE RESEARCH, Issue 9 2010
Mohammed Aliyu-Paiko
Abstract Nine isoenergetic (18.5 kJ g,1) diets were formulated, in a 3 × 3 factorial design, by varying three levels of dietary protein (350, 400 and 450 g kg,1) at each of three levels of dietary lipid (65, 90 and 115 g kg,1) accordingly. Each diet was hand fed two times daily for 8 weeks to triplicate homogenous groups of eight fish (average weight 3.34 ± 0.02 g) per tank connected to a recirculation system. Results showed that the feed efficiency and growth performance significantly (P<0.05) increased with increasing protein level at the two lower lipid levels (65 and 90 g kg,1), respectively, as indicated by indices such as %weight gain, specific growth rate, protein efficiency ratio, feed conversion ratio and feed intake, but did not at the highest lipid level (115 g kg,1). The muscle polyunsaturated fatty acids (PUFA) content declined with increasing dietary protein level at the lipid levels producing the highest growth, suggesting that the utilization of PUFA influences growth. Whereas the muscle monounsaturated fatty acids level was generally lower than the dietary levels in all the treatments tested, indicating preferential catabolism for energy, the muscle saturated fatty acids level was comparatively higher than in the diets, indicating selective deposition. Docosa hexaenoic acid (22:6n3, DHA), which was very low in the diet and in the initial fish, was higher in the muscle of some of the treatments, indicating the ability of Channa striatus to desaturate and elongate short-chain PUFA to long-chain HUFA, due to the availability of dietary 18:3n3 and 20:5n3 (the precursors for DHA biosynthesis). It could be concluded, based on the results of this trial, that a diet formulated to contain 65 g kg,1 lipid and 450 g kg,1 protein, with a gross energy of 18.5 kJ g,1 and a dietary n3/n6 PUFA ratio of about 0.1, is sufficient to promote good feed efficiency and growth performance in C. striatus fingerling. [source]

Live feeds for early stages of fish rearing

AQUACULTURE RESEARCH, Issue 5 2010
Luís E C Conceição
Abstract Despite the recent progress in the production of inert diets for fish larvae, feeding of most species of interest for aquaculture still relies on live feeds during the early life stages. Independently of their nutritional value, live feeds are easily detected and captured, due to their swimming movements in the water column, and highly digestible, given their lower nutrient concentration (water content>80%). The present paper reviews the main types of live feeds used in aquaculture, their advantages and pitfalls, with a special emphasis on their nutritional value and the extent to which this can be manipulated. The most commonly used live feeds in aquaculture are rotifers (Brachionus sp.) and brine shrimp (Artemia sp.), due to the existence of standardized cost-effective protocols for their mass production. However, both rotifers and Artemia have nutritional deficiencies for marine species, particularly in essential n-3 highly unsaturated fatty acids (HUFA, e.g., docosahexaenoic acid and eicosapentaenoic acid). Enrichment of these live feeds with HUFA-rich lipid emulsions may lead to an excess dietary lipid and sub-optimal dietary protein content for fish larvae. In addition, rotifers and Artemia are likely to have sub-optimal dietary levels of some amino acids, vitamins and minerals, at least for some species. Several species of microalgae are also used in larviculture. These are used as feed for other live feeds, but mostly in the ,green water' technique in fish larval rearing, with putative beneficial effects on feeding behaviour, digestive function, nutritional value, water quality and microflora. Copepods and other natural zooplankton organisms have also been used as live feeds, normally with considerably better results in terms of larval survival rates, growth and quality, when compared with rotifers and Artemia. Nonetheless, technical difficulties in mass-producing these organisms are still a constraint to their routine use. Improvements in inert microdiets will likely lead to a progressive substitution of live feeds. However, complete substitution is probably years away for most species, at least for the first days of feeding. [source]

Preliminary investigations on the effects of dietary lipid on the spawning performance and egg quality of black sea bass Centropristis striata L

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]

Dietary absorption efficiencies and toxicokinetics of polychlorinated biphenyls in ring doves following exposure to aroclor® mixtures

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2000
Ken G. Drouillard
Abstract Ring doves (Streptotpelia risoria) were fed a meal of pellets spiked with an Aroclor® mixture. Feces were collected from birds after fasting 31 h postexposure and dietary absorption efficiencies (AbE) of polychlorinated biphenyls (PCBs) were determined by mass balance. Polychlorinated biphenyl AbEs ranged from 0.86 to 0.97 for individual congeners and were similar to the lipid AbE of 0.90. The AbEs exhibited a declining trend with increasing chemical hydrophobicity. The toxicokinetics of PCBs and dietary lipids in blood plasma were also followed in the exposed birds for 25 h after feeding the contaminated meal. Despite decreasing trends in net AbEs with increasing chemical hydrophobicity, all PCBs exhibited similar blood toxicokinetics as observed for dietary lipids. The PCB plasma uptake rate constants exhibited a positive correlation with chemical hydrophobicity such that the most hydrophobic congener PCB 180 approached the plasma uptake rate constant measured for dietary lipids. Trends in assimilation kinetics of PCBs in blood were not consistent with the general prediction that solubility limitations of chemicals in the unstirred water layer (UWL) contribute to declines in net AbEs for highly hydrophobic chemicals. The data are consistent with a micelle-mediated diffusion model, which indicates that dietary lipids and hydrophobic contaminants can cross the UWL and enter intestinal tissues at equivalent rates; however, solubility limitations of highly hydrophobic chemicals in mixed micelles may contribute to decline in net AbEs. [source]

Expression levels of genes for ATP-binding cassette transporters and sterol 27-hydroxylase in liver and intestine of baboons with high and low cholesterolemic responses to dietary lipids

JOURNAL OF MEDICAL PRIMATOLOGY, Issue 3 2005
Rampratap S. Kushwaha
Abstract:, Baboons with high and low lipemic responses to dietary lipids differ in intestinal cholesterol absorption and hepatic cholesterol metabolism. ATP-binding cassette (ABC) transporters play an important role in cholesterol absorption and hepatic cholesterol metabolism. Using frozen tissues from high- and low-responding baboons maintained on the cholesterol and fat-enriched diet, we determined the relative expression of ABCA1, ABCG5, ABCG8, and 27-hydroxylase genes in the liver and intestine using TaqMan® real-time polymerase chain reaction. There was no consistent difference in the expression of ABC-transporters and 27-hydroxylase in the intestine between high- and low-responding baboons. However, hepatic expression of sterol 27-hydroxylase, ABCG5, and ABCG8 was higher in low-responding baboons than in high-responding baboons. There was also a significant correlation between the expression of sterol 27-hydroxylase and ABCG5, and ABCG8 in both the liver and the intestine. These results suggest that differences in hepatic lipid metabolism but not in cholesterol absorption between high- and low-responding baboons observed previously may be mediated by the differences in the expression levels of 27-hydroxylase, ABCG5, and ABCG8. [source]