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1.
Juvenile yellow perch Perca flavescens were fed semipurified diets with varying protein to metabolizable energy ratios (PME, g protein MJ−1 metabolizable energy) and nutrient densities in three experiments to determine recommended dietary protein and energy concentrations. Experiment 1 fish (18.6 g) were fed diets containing 450 g crude protein kg−1 dry diet and 14.5–18.8 MJ ME kg−1 dry diet for 10 weeks. No differences were found in the growth of experiment 1 fish fed the different diets. Experiment 2 fish (21.9 g) were fed diets containing 15.7 MJ ME kg−1 dry diet and 210–420 g crude protein kg−1 dry diet for 8 weeks. Fish fed the diet containing 340 g kg−1 protein (diet PME = 22) exhibited the greatest weight gain. Experiment 3 fish (27.1 g) were fed diets with a PME of 22 and varying nutrient density (yielding 205–380 g crude protein kg−1 dry diet) for 8 weeks. No differences were found in the growth of experiment 3 fish. Yellow perch fed the semipurified diets exhibited increased liver fat content, liver size and degree of liver discoloration compared with fish fed a commercial fish meal-based diet. Liver changes may have resulted from high dietary carbohydrate levels. We conclude that a protein level of 210–270 g kg−1 dry diet is suitable for juvenile yellow perch provided that the dietary amino acid profile and carbohydrate content are appropriate for yellow perch.  相似文献   

2.
Dietary phosphorus requirement of juvenile Atlantic salmon, Salmo salar L.   总被引：5，自引：0，他引：5  
The objective of this study was to determine the dietary phosphorus (P) requirement of juvenile Atlantic salmon, Salmon salar L. Triplicate groups of fish (mean initial weight 1.4 g) were fed semipurified, casein-gelatine-based diets containing one of five levels of P (4, 8, 10, 15 and 25 g kg−1) from Ca(H2PO4)2·H2O, or a commercial feed (17 g kg−1 P) for 9 weeks. Weight gains did not differ significantly among treatment groups fed the experimental diets but were slightly less than gains in fish fed the commercial feed. Feed efficiency (wet weight gain/dry feed consumed) was similar in all groups, averaging 1.45. Availability of dietary P, estimated from apparent retention and apparent digestibility, was 86%. Whole-body P concentrations declined in fish fed diets containing less than 10 g kg−1 P. Fitting a logistic curve to dietary P vs. whole-body P concentrations indicated that a minimum of 11 g kg−1 dietary P (9 g kg−1 digestible P) was required by juvenile Atlantic salmon to maintain whole-body P concentrations at initial levels. Calculation of a dietary requirement using a simple factorial model which incorporated measurements of P availability, feed efficiency and normal whole-body P concentration indicated that the dietary requirement was approximately 10 g kg−1. The dietary requirement established in this study (10–11 g kg−1) is higher than previously reported for Atlantic salmon or other fishes. Possible reasons for the wide range of reported dietary P requirements in fishes are discussed.  相似文献   

3.
An 8-week feeding experiment was conducted to determine the effect of dietary methionine supplementation on intestinal microflora and humoral immune of juvenile Jian carp (initial weight of 9.9 ± 0.0 g) reared in indoor flow-through and aerated aquaria. Eight amino acid test diets (350 g kg−1 crude protein, CP), using fish meal, soybean-condensed protein and gelatin as intact protein sources supplemented with crystalline amino acids, were formulated to contain graded levels of methionine (0.6–22.0%) at a constant dietary cystine level of 3 g kg−1. Each diet was randomly assigned to three aquaria. Growth performance and feed utilization were significantly influenced by the dietary methionine levels ( P  < 0.05). Maximum weight gain, feed intake occurred at 12 g kg−1 dietary methionine ( P  < 0.05). Methionine supplementation improved hepatopancreas and intestine weight, hepatosomatic and intestine index, intestinal γ-glutamyltransferase and creatine kinase activity, Lactobacillus count, Bacillus count, lysozyme activities, lectin potency, sim-immunoglobulin M content, addiment C3,C4 contents and serum total iron-binding capacity and declined Escherichia coli and Aeromonas counts. Quadratic regression analysis of weight gain against dietary methionine levels indicated that the optimal dietary methionine requirement for maximum growth of juvenile Jian carp is 12 g kg−1 of the dry diet in the presence of 3 g kg−1 cystine.  相似文献   

4.
Four diets (1, 2, 3 and 4) were formulated to contain different potato protein concentrate (PPC) levels (0, 22, 56, and 111 g kg−1). Diet 5 contained 56 g kg−1 PPC and 17 g kg−1 methionine. A growth trial was conducted to investigate the effect on growth and feed utilization of incorporation of PPC and supplementation of methionine in the diet of rainbow trout. When the proportion of PPC exceeded 56 g kg−1 the growth of fish decreased while both growth and feed utilization decreased when the dietary PPC was 111 g kg−1. Protein productive value and condition factor of the fish decreased and mortality increased with the increase in the proportion of dietary PPC.  相似文献   

5.
Two growth studies were conducted to determine the dietary threonine requirement of reciprocal cross hybrid striped (sunshine) bass. Semipurified diets were prepared with crystalline amino acids and lyophilized fish muscle to supply 350 g crude protein kg−1 diet. The basal diet contained 4.9 g threonine kg−1 from fish muscle, and test diets were supplemented with graded levels of L-threonine. In the first experiment, fish initially averaging ≊ 9.8 g each were fed diets containing threonine levels of 4.9, 7.5, 10.0, 12.5, 15.0 and 17.5 g kg−1 dry diet for 7 weeks. Weight gain, feed efficiency and protein efficiency ratio (PER) were significantly ( P < 0.01) influenced by dietary threonine level. Based on weight-gain responses, a threonine requirement (± SE) of 8.4 (± 0.8) g kg−1 dry diet was determined, and dietary threonine levels of 10.0 g kg−1 diet or greater resulted in the highest levels of free threonine in plasma.
Based on the results of the first experiment, a second feeding trial was conducted with diets containing threonine levels of 4.9, 6.5, 8.0, 9.5, 11.0 and 12.5 g kg−1 dry diet. Fish initially averaging ≊ 3.0 g each were fed each diet for 8 weeks. Weight gain, feed efficiency and PER values of fish were markedly improved, with increases in dietary threonine up to 8.0 g kg−1 dry diet. Regression analysis of weight gain, feed efficiency and PER data using the broken-line model resulted in threonine requirement estimates of 9.7, 8.5 and 8.6 g kg−1 dry diet, respectively. Based on these data, the threonine requirement of juvenile sunshine bass was determined to be ≊ 9.0 g kg−1 dry diet or 26 g kg−1 of dietary protein.  相似文献   

6.
This study was conducted to evaluate three canola protein products as partial replacements of steam-dried whole herring meal (HM) in a practical diet for juvenile chinook salmon in seawater. Groups of 30–40 g chinook salmon held in 9.5–12°C seawater on a natural photoperiod were fed one of seven equivalent protein (390 g kg−1) and isoenergetic (20 MJ gross energy kg−1) diets to satiation. Each of three test protein sources, namely, commercial canola meal (CM), low-temperature extruded CM (90°C; LT), and high-temperature extruded CM (150°C; HT) comprised about 120 and 240 g kg−1 of dietary protein by replacement of 15 and 30%, respectively, of the HM protein in the control diet. Chinook salmon growth and feed intake were markedly depressed by replacing HM protein with a high level of CM, but these responses were not lowered by replacement with LT and HT. The phytic acid content in commercial canola meal was reduced by about 10 and 30% from the original level by extrusion cooking at low (90°C) and high (150°C) temperature, respectively. Therefore, the diets containing HT still had significant amounts of phytic acid. Terminal whole-body zinc contents were inversely related to the dietary levels of the different canola protein products. Thyroid function was altered by CM but this effect was offset by heat treatment. The results suggest that extrusion cooking of CM improves its nutritive value for chinook salmon in seawater. Indeed, it was found that HT could comprise 240 g kg−1 of the dietary protein without adversely affecting performance.  相似文献   

7.
The objective of the present study was to investigate the effect of dietary phospholipid (PL) level on growth and feed intake of juvenile amberjack ( Seriola dumerili ) fed non-fishmeal (non-FM) diet containing alternative protein sources; soybean protein isolate, tuna muscle by-product powder and krill meal. Three non-FM diets were prepared to contain three levels (14, 37 and 54 g kg−1 dry diet) of PL (soybean lecithin acetone insoluble, 886 g kg−1) and growth performance was monitored in a 30-day growth trial by using 2.6 g of fish. The results indicated that final body weight, weight gain and feed intake significantly increased with increasing dietary PL level. At the highest dietary PL level (54 g kg−1 dry diet), the fish consumed 14.8% and 10.2% as much feed as those fish fed diets containing 14 g kg−1 dry diet and 37 g kg−1 dry diet PL, respectively. An increasing tendency with increasing dietary PL level on feed efficiency was observed. In conclusion, the present study demonstrated that dietary PL supplementation could increase feed intake, and improve the growth of juvenile S. dumerili fed non-FM diets. Therefore, purified PL might be a good candidate to stimulate the growth of fish through enhancing the feed intake when they are fed diets containing alternative protein sources.  相似文献   

8.
The effect of five experimental diets with different crude protein content (220, 270, 330, 390 and 450 g kg−1) on gonad development of female Cherax quadricarinatus was tested under laboratory conditions. After 70 days, a significant linear relationship indicated that higher concentrations of protein and carbohydrates in the hepatopancreas were produced as the dietary crude protein increased ( P  < 0.05). There were significant responses of the gonadosomatic index, hepatosomatic index, biochemical composition of the gonad (protein, lipids, carbohydrates and energy) and frequency of secondary vitellogenic oocytes to dietary protein level, as indicated by significant fits of the quadratic equation to the observed experimental data. The optimal response of the criteria parameters corresponded to levels of crude protein in the range 284–355 g kg−1. Overall, 330 g kg−1 crude protein with a protein : energy ratio of 15.6 mg kJ–1 was considered the most adequate concentration of dietary protein for gonad development and biochemical composition in female redclaw crayfish.  相似文献   

9.
High-energy diets for white sturgeon, Acipenser transmontanus Richardson   总被引：1，自引：0，他引：1  
Four diets formulated for salmon were fed to 0.11 kg white sturgeon, Acipenser transmontanus Richardson, for 8 weeks. Dietary compositions ranged from 258 to 402 g lipid kg−1, 535–378 g protein kg−1 and 22.7–14.4 g protein MJ−1 gross energy.
Fish in all treatments grew rapidly, utilized the diets efficiently and had body compositions similar to what has been found in previous studies, but there were some dietary effects. Sturgeon fed the diet with the highest lipid content and lowest protein/energy ratio had lower ( P < 0.05) specific growth rate, feed efficiency, and liver moisture and protein contents, and 6-phosphogluconate dehydrogenase activity, but higher liver lipid contents than fish fed the other three diets. Condition factor, organ to body weight ratios, whole-body and plasma concentrations of protein, glucose and triglyceride, and liver glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase and malic enzyme activities did not differ significantly among dietary treatments. This suggests that white sturgeon subyearlings can utilize diets with high lipid contents (258–357 g kg−1) to display good growth without major adverse effects on body composition and liver lipogenic enzyme activities.  相似文献   

10.
Haematopoiesis and blood cells' functions can be influenced by dietary concentration of nutrients. This paper studied the effects of dietary protein:energy ratio on the growth and haematology of pacu, Piaractus mesopotamicus . Fingerling pacu (15.5±0.4 g) were fed twice a day for 10 weeks until apparent saciety with diets containing 220, 260, 300, 340 or 380 g kg−1 crude protein (CP) and 10.88, 11.72, 12.55, 13.39, 14.22 MJ kg−1 digestible energy (DE) in a totally randomized experimental design, 5 × 5 factorial scheme ( n =3). Weight gain and specific growth rate were affected ( P <0.05) by protein level only. Protein efficiency ratio decreased ( P <0.05) with increasing dietary protein at all levels of dietary energy. Daily feed intake decreased ( P <0.05) with increasing dietary energy. Mean corpuscular haemoglobin concentration was affected ( P <0.05) by DE and interaction between dietary CP and DE. Total plasma protein increased ( P <0.05) with dietary protein and energy levels. Plasma glucose decreased ( P <0.05) with increasing dietary protein. The CP requirement and optimum protein:energy ratio for weight gain of pacu fingerlings, determined using broken-line model, were 271 g kg−1 and 22.18 g CP MJ−1 DE respectively. All dietary CP and DE levels studied did not pose damages to fish health.  相似文献   

11.
The objectives of this study were to describe the interactive effects of varying digestible protein (DP) and digestible energy (DE) contents on the feed intake, growth, protein utilization and whole body composition of juvenile mulloway ( Argyrosomus japonicus ) and to determine the optimal DP : DE ratio for growth. This was achieved by feeding mulloway diets containing one of four different DP levels (250–550 g kg−1) at two DE levels (16 or 21 MJ kg−1). Juvenile mulloway were stocked at each of two different sizes (70 or 200 g) in triplicate groups for each dietary treatment and fed twice daily to apparent satiation over 58 days. The results indicated that feed intake was not governed solely by energy demands but was also dependant on the DP content of the diet. Protein utilization did not improve with diets containing decreasing protein and increasing lipid content indicating that mulloway have a limited capacity to spare DP. Optimal DP content was found to be 444–491 g kg−1 depending on the DE content of the diet and the size of mulloway and is within the range reported for other sciaenid species. The use of formulated diets with 28.6 g of DP MJ DE−1 will achieve optimal growth and protein deposition for 70–275 g mulloway.  相似文献   

12.
Four practical diets containing different levels of soybean cake (0, 155, 320, 490 g kg−1) were prepared to investigate the effect of replacement of fishmeal by soybean cake on the Chinese longsnout catfish ( Leiocassis longirostris Günther) during a 62-day growth trial. The diets were isonitrogenous, isoenergetic and contained about 430 g kg−1 crude protein and 20 MJ kg−1 gross energy. With increasing levels of dietary soybean cake, growth rate and feed utilization decreased; feeding rate and the contents of dry matter, fat and energy of fish body were not significantly affected while body protein showed lowest value in the fish fed the diet containing 320 g kg−1 soybean cake.  相似文献   

13.
An 8-week feeding trial was conducted to determine the threonine requirement of juvenile Pacific white shrimp Litopenaeus vannamei (Boone) in low-salinity water (0.50–1.50 g L−1). Diets 1–6 were formulated to contain 360 g kg−1 crude protein with fish meal, wheat gluten and pre-coated crystalline amino acids with six graded levels of l -threonine (9.9–19.0 g kg−1 dry diet). Diet 7, which was served as a reference, contained only intact proteins (fish meal and wheat gluten). Each diet was randomly assigned to triplicate groups of 30 shrimps (0.48±0.01 g), each four times daily. Shrimps fed the reference diet had similar growth performance and feed utilization efficiency compared with shrimps fed the diets containing 13.3 g kg−1 or higher threonine. Maximum specific growth rate (SGR) and protein efficiency ratio were obtained at 14.6 g kg−1 dietary threonine, and increasing threonine beyond this level did not result in a better performance. Body compositions, triacyglycerol and total protein concentrations in haemolymph were significantly affected by the threonine level; however, the threonine contents in muscle, aspartate aminotransferase and alanine aminotransferase activities in haemolymph were not influenced by the dietary threonine levels. Broken-line regression analysis on SGR indicated that optimal dietary threonine requirement for L. vannamei was 13.6 g kg−1 dry diet (37.8 g kg−1 dietary protein).  相似文献   

14.
Six isonitrogenous [450 g kg−1 crude protein (CP)] and isoenergetic diets (23 kJ g−1) with six levels of defatted soybean meal inclusion (0, 132, 263, 395, 526 and 658 g kg−1) in substitution of fish meal were evaluated in gilthead sea bream of 242 g initial weight for 134 days. Fish fed diets S0, S13, S26 and S39 had a similar live weight (422, 422, 438 and 422 g, respectively) but fish fed diets S53 and S66 obtained the lowest final weight (385 and 333g, respectively), and similar results were presented in specific growth rate (SGR). Fish fed diets S53 and S66 also obtained the highest feed conversion ratio (FCR). Quadratic multiple regression equations were developed for SGR and FCR which were closely related to dietary soybean level. The optimum dietary soybean levels were 205 g kg−1 for maximum SGR and 10 g kg−1 for minimum FCR. Sensorial differences were appreciated by judges between fish fed S0 and S39 soybean level, but after a re-feeding period of 28 days with diet S0, these differences disappeared.  相似文献   

15.
Five iso-nitrogenous (300 g protein kg−1 diet) and iso-lipidic (80 g kg−1 diet) semi-purified experimental diets with variable energy levels of 10.5 (D-1), 12.5 (D-2), 14.6 (D-3), 16.7 (D-4) and 18.8 (D-5) MJ kg−1 diets were fed to Puntius gonionotus fingerlings (average weight 1.79 ± 0.02 g) in triplicate groups (15 healthy fishes per replicate) for a period of 90 days to assess the optimum dietary energy level and protein-to-energy ratio (P/E). Fifteen flow-through cement tanks of 100 L capacity with a flow rate of 0.5 L min−1 were used for rearing the fish. Maximum specific growth rate, protein efficiency ratio, protein productive value, RNA : DNA ratio, whole body protein content, digestive enzyme activity and minimum feed conversion ratio was found in fish-fed diet D-3 with 14.6 MJ kg−1 energy level. There were no improvements in all these parameters with the further rise in dietary energy level. Hence, it may be concluded that the optimum dietary gross energy level for maximum growth and nutrient utilization of silver barb is 14.6 MJ kg−1 diet with a resultant P/E ratio of 20.2 g protein MJ−1 diet, when the dietary protein and lipid are maintained at optimum requirement levels of 300 and 80 g kg−1 diet, respectively, for this species.  相似文献   

16.
Five iso-nitrogenous (300 g crude protein kg−1 diet) semi-purified diets with graded levels of carbohydrate at 220 (D-1), 260 (D-2), 300 (D-3), 340 (D-4) and 380 (D-5) g kg−1 diet were fed ad libitum to Puntius gonionotus fingerlings (average weight 0.59±0.01 g) in triplicate groups (20 fish replicate−1) for a period of 90 days to determine the effect of the dietary carbohydrate level on the growth, nutrient utilization, digestibility, gut enzyme activity and whole-body composition of fish. Fifteen flow-through cement tanks of 100 L capacity with a flow rate of 0.5 L min−1 were used for rearing the fish. The maximum weight gain, specific growth rate, protein efficiency ratio, RNA:DNA ratio, whole-body protein content, protease activity, protein and energy digestibility and minimum feed conversion ratio (FCR) were found in the D-2 group fed with 260 g carbohydrate kg−1 diet. The highest protein and energy retention was also recorded in the same group. However, from the second-order polynomial regression analysis, the maximum growth and nutrient utilization of P. gonionotus fingerlings was 291.3–298.3 g carbohydrate kg−1 diet at a dietary protein level of 300 g kg−1 with a protein/energy (P/E) ratio of 20.58 −20.75 g protein MJ−1.  相似文献   

17.
The quantitative dietary sulphur amino acid requirement of the Indian major carp, Labeo rohita (Hamilton), was determined by conducting a growth study. The experimental diets contained 400 g crude protein kg−1 from casein, gelatine and supplemental crystalline amino acids. Diets containing six graded levels of methionine (3.2, 6.5, 9.0, 11.5, 14 and 16.5 g kg−1) with a constant level of cystine (1.4 g kg−1) were formulated and fed to triplicate groups of Labeo rohita fingerlings twice a day to satiation for 60 days. The optimum dietary requirement for methionine was estimated using the break-point regression analysis at 11.5 g kg−1 of diet or 28.8 g kg−1 of dietary protein. Thus the total sulphur amino acid (Met + Cys) requirement was determined to be 12.9 g kg−1 of diet or 32.3 g kg−1 of protein. Higher survival, specific growth rate and food conversion efficiency values were observed for fish fed the diet containing optimum levels of sulphur amino acids.  相似文献   

18.
Two feeding experiments were conducted to assess the quantitative cholesterol requirement of the juvenile prawn, Penaeus japonicus . The prawns were fed casein-based (experiment 1) and casein- or crab protein-based (experiment 2) diets with or without supplemental cholesterol. The daily increases in quantities of body cholesterol (mg kg−1 prawn day−1) at maximum growth and dietary cholesterol intake over a 40-day feeding period were determined. Prawns fed 5 g kg−1 supplemental cholesterol, regardless of protein sources, gave the highest weight gain. Body retention efficiencies of dietary cholesterol (cholesterol retained × 100/cholesterol intake) vary among prawns fed 5 g kg−1 supplemental cholesterol (diets 3, 5 and 7) but dietary cholesterol requirements expressed as mg kg−1 body weight (BW) day−1 were not significantly different (180 to 200 mg kg−1 BW day−1). Based on dietary cholesterol requirement, the optimum dietary cholesterol levels for the juvenile prawns were estimated in relation to feeding levels. When feeding levels were 3%, 5% and 7% of body weight, optimum dietary cholesterol levels were 5.0 to 6.0, 3.6 to 4.0, and 2.6 to 2.9 g kg−1 of dry diet, respectively. The present study showed the advantages of determining daily cholesterol requirement (mg kg−1 BW day−1) at maximum growth through a factorial method in determining optimum dietary cholesterol levels in P. japonicus .  相似文献   

19.
The potential of waste date meal (WDM; low-quality date palm, Phoenix dactylifera L.) as a carbohydrate source in formulated diets for Nile tilapia was evaluated. Four isocaloric-practical diets (15.7 kJ g−1) were formulated incorporating WDM at 0, 100, 200 and 300 g kg−1 levels as partial substitutes for soybean meal (SBM). These were designated D0 [284 g crude protein (CP) and 383 g carbohydrate (CHO) kg−1 diet], D1 (279 g CP and 446 g CHO kg−1 diet), D2 (207 g CP and 495 g CHO kg−1 diet) and D3 (175 g CP and 578 g CHO kg−1 diet). Each diet was fed to three replicate groups of 30 fish [20.20 ± 0.09 g (±SE)] for 75 days. No feed-related mortality was observed during the entire experimental period. Final body weight (FBW) and specific growth rate (SGR) in the different treatments were statistically not significantly different ( P  > 0.05). Protein efficiency rate (PER) was lowest in diet D0 and increased with decrease of SBM content (D1–D3). A significant increase in whole body lipid content was recorded in fish fed diets D2 and D3. Results showed that WDM could be a substitute for SBM up to 300 g kg−1 in practical Nile tilapia diets without compromising growth.  相似文献   

20.
The study was conducted to investigate the effect of dietary protein on nitrogenous excretion in the form of ammonia in Indian major carp, Labeo rohita (Ham.), fingerlings (3.0 ± 0.25 g). Fish were fed to satiation in a metabolism chamber. Approximately isoenergetic diets containing 230, 280, 330 and 380 g kg−1 protein were used at 28°C. Ammonia-N excretory energy ( U ) as a percentage of ingested food energy ( C ) increased with an increase in dietary protein level: from 4.3% in fish fed 230 g kg−1 to 6.0% in fish fed 380 g kg−1 dietary protein. The relationship between excretory energy and dietary protein level is modelled.  相似文献   

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