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1.
An 8-week feeding experiment was conducted to evaluate the dietary leucine requirement of fingerling Indian major carp, Labeo rohita (3.50±0.04 cm; 0.40±0.02 g) using amino acid test diets (40% crude protein; 17.90 kJ g−1 gross energy) containing casein and gelatin as intact protein sources and l -crystalline amino acids. Growth performance and biochemical parameters were assessed by feeding six amino acid test diets supplemented with graded concentrations of leucine (0.75, 1.0, 1.25, 1.50, 1.75 and 2.0 g per 100 g) to triplicate groups of fingerlings to apparent satiation divided over two feedings at 07:00 and 17:30 hours. Performance of the fish was evaluated on the basis of live weight gain, feed conversion ratio (FCR), protein efficiency ratio (PER) and body protein deposition (BPD) data. Maximum live weight gain (315%), best FCR (1.35), highest PER (1.86) and BPD (33.9) were recorded at 1.50 g per 100 g dietary leucine. Statistical analysis of live weight gain, FCR, PER and BPD data reflected significant differences (P<0.05) among treatments. Live weight gain, FCR, PER and BPD data were also analysed using second-degree polynomial regression analysis to obtain more accurate leucine requirement estimate which was found to be at 1.57, 1.55, 1.52 and 1.50 g per 100 g of dry diet, corresponding to 3.92, 3.87, 3.80 and 3.75 g per 100 g of dietary protein respectively. Based on the quadratic regression analysis of the live weight gain, FCR, PER and BPD data, the optimum requirement of fingerling L. rohita for leucine is estimated to be in the range of 1.50–1.57 g per 100 g of the dry diet, corresponding to 3.75–3.92 g per 100 g of dietary protein.  相似文献   

2.
An 8‐week feeding experiment was conducted in a water flow‐through system (26–28 °C) to determine the dietary threonine requirement of fingerling Labeo rohita (3.90±0.03 cm; 0.58±0.02 g). Growth, feed utilization and body composition of fish fed test diets (40% crude protein; 17.9 kJ g?1 gross energy) with graded levels of l ‐threonine (0.75%, 1.0%, 1.25%, 1.50%, 1.75% and 2.0% dry diet) to apparent satiation were response variables used to assess threonine adequacy. Diets were made isonitrogenous and isoenergetic by adjusting the levels of glycine and dextrin. The amino acid profiles of the test diets were formulated to that of 40% whole chicken egg protein except for threonine. The performance of fish fed experimental diets was evaluated using calculated values for weight gain (g fish?1), feed conversion ratio (FCR), protein efficiency ratio (PER) and protein productive value (PPV) data. Maximum weight gain (g fish?1) (1.79), lowest FCR (1.39), highest PER (1.76) and PPV (0.33) were recorded at 1.50 g per 100 g dietary threonine. Statistical analysis of weight gain, FCR, PER and PPV data reflected significant differences (P<0.05) among treatments. Except for reduced growth performance in fish fed threonine‐deficient diets, no deficiency signs were noted. Weight gain, FCR, PER and PPV data were also analysed using second‐degree polynomial regression analysis to obtain a more accurate threonine requirement estimate, which was found, using each response variable, to be at 1.70, 1.63, 1.65 and 1.51 g per 100 g of dry diet, corresponding to 4.2, 4.07, 4.12 and 3.77 g per 100 g of dietary protein respectively. Based on the second‐degree polynomial regression analysis of the live weight gain, FCR, PER and PPV data, the optimum dietary level of threonine for fingerling L. rohita was found to be in the range of 1.51–1.70 g per 100 g of the dry diet, corresponding to 3.77–4.2 g per 100 g of dietary protein.  相似文献   

3.
The dietary arginine requirement of fingerling hybrid Clarias (Clarias gariepinus×Clarias macrocephalus) (4.2±0.03 cm, 0.56±0.04 g) was determined by feeding six isonitrogenous (400 g kg−1 crude protein) and isocaloric (17.9 kJ g−1) amino acid test diets containing casein, gelatin and l ‐crystalline amino acids with graded levels of arginine (10.0, 12.5, 15.0, 17.5, 20.0 and 22.5 g kg−1) for 4 weeks to triplicate groups. Diets were fed twice a day at 09:00 and 16:00 hours at 8% body weight day−1. Maximum weight gain (523%), best feed conversion ratio (FCR, 1.41), protein efficiency ratio (1.78) and specific growth rate (6.53%) were recorded in fish fed the diet containing arginine at 20.0gkg−1 of the diet. Second‐degree polynomial regression analysis of live weight gain and FCR values indicated the dietary arginine requirement at 17.8 and 20.0 g kg−1 of dry diet respectively. Significantly higher carcass protein and protein deposition values were recorded at the requirement level (20.0 g kg−1). Higher fat and lower moisture values were obtained in carcass of fish fed the diet with 15.0g kg−1 arginine. The maximum carcass ash value was noticed in the fish fed at 20.0 g kg−1 dietary arginine. We recommend that the diet for hybrid Clarias (C. gariepinus×C. macrocephalus) should contain arginine in the range of 17.8–20.0 g kg−1 of the dry diet, corresponding to 44.5 and 50 g kg−1 of dietary protein respectively.  相似文献   

4.
An 8‐week growth trial was conducted to determine the dietary histidine requirement of the Indian major carp, Cirrhinus mrigala fingerling (length 4.22 ± 0.45 cm; weight 0.61 ± 0.08 g; n = 40). Isonitrogenous (400 g kg?1 crude protein) and isoenergetic (17.90 kJ g?1 gross energy) diets with graded levels of l ‐histidine (2.5, 5.0, 7.5, 10.0, 12.5 and 15.0 g kg?1 dry diet) were formulated using casein and gelatin as a source of intact protein, supplemented with l ‐crystalline amino acids. Twenty fish were randomly stocked in 70‐L indoor polyvinyl circular fish tank (water volume 55‐L, water exchange rate 1–1.5 L min?1) and fed experimental diets at the rate of 5% of their body weight/day divided over two feedings at 08:00 and 16:00 h. Maximum live weight gain (295%), best feed conversion ratio (FCR) (1.48) and protein efficiency ratio (PER) (1.69) occurred at 7.5 g kg?1 of dietary histidine level. When live weight gain, FCR and PER data were analysed using second‐degree polynomial regression, the break points indicated histidine requirements at 9.4, 8.6 and 8.5 g kg?1 of dry diet respectively. Significantly (P < 0.05) higher whole body protein and low moisture values were recorded at 7.5 g kg?1 histidine level. Body fat increased significantly (P < 0.05) with increasing histidine levels. However, at 7.5 and 10 g kg?1 histidine diets body fat did not differ (P > 0.05) to each other. Ash content of fish fed diets containing various levels of histidine did not differ except at 2.5 and 5.0 g kg?1 inclusion levels where significantly (P < 0.05) higher ash was recorded. Protein deposition was also found to be significantly (P < 0.05) higher in the 7.5 g kg?1 histidine diet. Based on the polynomial regression analysis of FCR and PER data, it is recommended that the diet for fingerling C. mrigala should contain histidine at 8.5 g kg?1 of dry diet, corresponding to 21.25 g kg?1 of dietary protein for optimum growth and efficient utilization of feed.  相似文献   

5.
This study examined the effect of dietary protein and lipid levels on growth, feed utilization and body composition of Asian catfish Pangasius hypophthalmus reared in cages. Eight test diets were formulated at four protein (340, 380, 420 and 460 g kg−1 crude protein) and two lipid (50 and 90 g kg−1 crude lipid) levels. Fish (initial weight 4.7 g fish−1) were fed the test diets for 8 weeks. Final body weight, weight gain (WG), feed intake (FI), feed conversion ratio (FCR), contents of crude protein, lipid and energy in whole body were dependent on both dietary protein and lipid levels, while specific growth rate (SGR), hepatosomatic index and body moisture content were dependent on dietary lipid level. The WG and SGR increased with the increase in either dietary protein level (at the same lipid level) or lipid level (at the same protein level). The FI and FCR decreased with the increase in dietary protein level (at the same lipid level) or lipid level (at the same protein level). Protein sparing action occurred in case dietary lipid level increased. Fish fed the diet containing 453 g kg−1 crude protein and 86 g kg−1 lipid had the highest WG and SGR, but the lowest FI and FCR, among the diet treatments. There were no significant differences in the protein retention efficiency (PRE) and energy retention efficiency (ERE) among the diet treatments, although PRE and ERE were relatively high in fish fed the diet containing 453 g kg−1 crude protein and 86 g kg−1 lipid. At the end of the feeding trial, body protein content increased, while body lipid content decreased, with the increase in dietary protein content at the same lipid level. Our results suggest that dietary levels of 450 g kg−1 crude protein and 90 g kg−1 lipid are adequate to support fast growth of P. hypophthalmus reared in cages.  相似文献   

6.
A 9‐week feeding trial was conducted to estimate the dietary isoleucine requirement of juvenile blunt snout bream. Six isonitrogenous and isoenergetic experimental diets were formulated to contain graded isoleucine levels ranging from 5.3 to 20.1 g kg?1 dry diet. At the end of the experiment, weight gain (WG), specific growth rate (SGR), feed efficiency ratio (FER) and protein efficiency ratio (PER) increased with increasing dietary isoleucine level up to 11.1 g kg?1 dry diet, and dietary isoleucine level above 14.2 g kg?1 dry diet declined these performances. Dietary isoleucine levels (14.2 and 17.3 g kg?1 dry diet) significantly improved whole‐body protein content, but decreased whole‐body lipid, plasma triglyceride and cholesterol contents. Significantly lower visceral fat index (VFI) in fish fed with 14.2 g kg?1 dietary isoleucine was observed compared to those fed with deficient or excessive isoleucine. Dietary isoleucine supplementation significantly increased plasma isoleucine concentration, while plasma valine and leucine concentrations showed a reversed trend. Dietary isoleucine levels regulated the target of rapamycin (TOR) gene expression and improved plasma superoxide dismutase (SOD) activity in juvenile blunt snout bream. Based on second‐order polynomial regression model analysis of SGR and FER, the optimum dietary isoleucine requirement was estimated to be 13.8 g kg?1 dry diet (40.6 g kg?1 dietary protein) and 14.0 g kg?1 dry diet (41.2 g kg?1 dietary protein), respectively.  相似文献   

7.
To evaluate isolated pea protein as feed ingredient for tilapia (Oreochromis niloticus) juveniles, triplicate groups were fed with four isonitrogenous [crude protein: 421.1–427.5 g kg−1 in dry matter (d.m.)] and isoenergetic (gross energy: 20.46–21.06 MJ kg−1 d.m.) diets with varying protein sources for 8 weeks. Fish meal-based protein content of diets was substituted with 0% (diet 100/0=control group), 30% (diet 70/30), 45% (diet 55/45) and 60% (diet 40/60) isolated pea protein. Tilapia juveniles with an initial body weight of 2.23–2.27 g were fed in average at a level of 5% of their body weight per day. Highest individual weight gain (WG: 21.39 g) and specific growth rate (SGR: 4.21% day−1) and best feed conversion ratio (FCR: 0.90) were observed in tilapia fed diet 100/0, followed by fish-fed diet 70/30 (WG: 19.09 g; SGR: 4.03% day−1; FCR: 0.98), diet 55/45 (WG: 16.69 g; SGR: 3.80% day−1; FCR: 1.06) and diet 40/60 (WG: 16.18 g; SGR: 3.74% day−1; FCR: 1.06). Although fish fed diet 100/0 showed the best performance, inclusion of 30% protein derived from pea protein isolate resulted in a growth performance (in terms of WG and SGR) that did not differ significantly from diet 100/0 in contrast to fish fed diet 55/45 and 40/60. Crude ash content in the final body composition of the experimental fish decreased with increasing dietary pea protein content, while crude protein and lipid content remained equal between the groups. Significant decreasing growth performance and body ash incorporation of tilapia at higher inclusion levels seem to be mainly related to the dietary amino acid profile and phytic acid contents.  相似文献   

8.
Dietary arginine requirement of fingerling Indian major carp, Cirrhinus mrigala (4.20 ± 0.05 cm; 0.60 ± 0.02 g) was determined by conducting a 8‐week feeding trial with casein–gelatine‐based diets (400 g kg?1 crude protein; 17.90 kJ g?1, gross energy), containing crystalline amino acids with graded levels of l ‐arginine (10, 12.5, 15, 17.5, 20 and 22.5 g kg?1, dry diet). Fish were randomly stocked, in triplicate groups, in 55‐L indoor polyvinyl flow through circular tanks and fed experimental diets at 5% of their body weight divided into two feedings at 08.00 and 16.00 hours. Live weight gain (321%) and feed conversion ratio (FCR 1.40) were significantly (P < 0.05) higher in fish fed diet containing 17.5 g kg?1dietary arginine compared with other diets. Second‐degree polynomial regression analysis of live weight gain, FCR and protein efficiency ratio data indicated requirements for dietary arginine at 18.7, 18.4 and 18.3 g kg?1 of the dry diet, respectively. Maximum carcass protein, and minimum moisture and fat contents were noticed at the requirement level. Carcass ash content remained insignificantly different among the treatments except at 17.5 g kg?1 dietary arginine showing significantly higher ash content. Based on the above results, it is recommended that the diet for fingerling C. mrigala should contain arginine at 18.4 g kg?1, dry diet, corresponding to 46 g kg?1 dietary protein for optimum growth and efficient feed utilization.  相似文献   

9.
An 8-week feeding trial was conducted in a flow-through system (1–1.5 L min−1) at 27°C to determine dietary protein requirement for Channa punctatus fingerlings (4.58 ± 0.29 g) by feeding six isocaloric diets (18.39 kJ g−1, gross energy). Diets containing graded levels of protein (300, 350, 400, 450, 500 and 550 g kg−1) were fed to triplicate groups of fish to apparent satiation at 09:00 and 16:00 h. Maximum absolute weight gain (AWG; 8.11 g fish−1), specific growth rate (SGR; 1.82%) and best feed conversion ratio (FCR; 1.48) were recorded in fish fed diet containing 450 g kg−1 protein, whereas protein efficiency ratio (PER; 1.52), protein retention efficiency (PRE; 25%), energy retention efficiency (ERE; 78%) and RNA/DNA ratio (3.01) were maximum for the group fed dietary protein at 400 g kg−1. Second-degree polynomial regression analysis of AWG, SGR and FCR data against varying levels of dietary protein yielded optimum dietary protein requirement of fingerling between 462.24 and 476.72 g kg−1, whereas the regression analysis of PER, PRE, ERE and RNA/DNA ratio data showed a lower protein requirement of 438.28–444.43 g kg−1 of the diet. Considering the PER, PRE, ERE and RNA/DNA ratio as more reliable indicators, this protein requirement is recommended for developing quality protein commercial feeds for C. punctatus fingerlings.  相似文献   

10.
An 15 week two set of feeding experiments were conducted to determine the dietary niacin requirement of Indian major carp fingerlings Labeo rohita and Cirrhinus mrigala, using casein gelatin–based diet. In both experiments, six isonitrogenous (40%) and isoenergetic (15.35 kJ g−1) test diet, with graded levels of niacin (0–50 mg kg−1 dry diet) in gradation of 10 mg kg−1 dry diet, were formulated. In first experiment, fingerling of L. rohita (4.20 ± 1.22 cm; 0.632 ± 0.67 gm) were randomly stocked, in triplicate groups, in 55-L indoor polyvinyl flow-through system (1.5 L min−1) and fed experimental diet at 0800 and 1600 h. Maximum live weight gain (1214%), feed conversion ratio (1.55) and protein efficiency ratio (1.60) were recorded at 30 mg dietary niacin diet. In second experiment, C. mrigala (4.50 ± 1.25 cm, 0.665 ± 0.88) were stocked in same setup. At the end of experiments, maximum live weight gain (1248%), FCR (1.47) and PER (1.70) occurred at 30 mg dietary niacin diet. However, the weight gain, FCR and PER data were analyzed by polynomial regression analysis indicating the requirement of niacin for L. rohita at 36.69, 33.06 and 32.0 mg kg−1, respectively, and for C. mrigala at 35.19, 28.69 and 27.70 mg kg−1 of dry diet, respectively. Whole body composition also showed significant (P < 0.05) differences among each other. On the basis of regression analysis of growth data, it is recommended that the diet for fingerlings should contain niacin at 33 and 30 mg kg−1 dry diet for L. rohita and C. mrigala, respectively.  相似文献   

11.
An 8‐week feeding trial was conducted to determine the optimum dietary methionine (Met) requirement of juvenile Pseudobagrus ussuriensis with an initial average weight of 0.60 g reared in indoor flow‐through and aerated aquaria. Six isonitrogenous (430 g kg?1 protein) and isolipidic (50 g kg?1 lipid) test diets were formulated to contain graded levels of crystalline L‐methionine (4.9, 9.0, 11.8, 14.2, 18.1 and 20.8 g kg?1 dry diets, respectively) at a constant dietary cystine level of 2.5 g kg?1 dry diets. Equal amino acid nitrogen was maintained by replacing methionine with non‐essential amino acid mixture. Fish were randomly allotted to 18 aquaria (1.0 × 0.5 × 0.8 m) with 50 fish to each glass aquarium. Fish were fed twice daily (08:00 and 16:00) to apparent satiation. No significant difference was observed in survival of fish (84.67–91.33%). Specific growth rate (SGR), weight gain (WG), feed conversion ratio (FCR), protein productive value (PPV) and protein efficiency ratio (PER) were significantly affected by different dietary methionine levels (P < 0.05). WG, SGR PPV and PER increased, while FCR decreased with increasing dietary methionine level from 4.9 to 11.8 g kg?1 (P < 0.05). However, with further increase from 11.8 to 20.8 g kg?1, WG, SGR PPV and PER significantly decreased, FCR increased (P < 0.05). The whole body and muscle composition were affected by different dietary methionine levels (P < 0.05). Condition factor (CF) increased with increasing dietary methionine levels up to 11.8 g kg?1 (P < 0.05) and after 11.8 g kg?1 methionine diet, but not significant, declines were observed (P > 0.05). Hepatosomatic index (HSI) of the 4.9, 9.0, 11.8 and 14.2 g kg?1 Met diets was significantly higher than that of fish fed diets 18.1 and 20.8 g kg?1 Met diets (P < 0.05). Viscerosomatic index (VSI) of the 4.9, 9.0 and 11.8 g kg?1 Met diets was significantly higher than that of fish fed diets 14.2, 18.1 and 20.8 g kg?1 Met diets (P < 0.05). Quadratic regression analysis of WG and PER against dietary methionine levels indicated that the optimal dietary methionine requirement for maximum growth and feed utilization of juvenile Pseudobagrus ussuriensis was 14.3 and 14.1 g kg?1 dry diet (35.3 and 34.8 g kg?1 dietary protein), respectively, in the presence of 2.5 g kg?1 dry diets cystine.  相似文献   

12.
《Aquaculture Research》2017,48(4):1759-1766
A shrimp protein hydrolysate (SPH) containing 894.2 g kg−1 crude protein (CP) and 54.3 g kg−1 total lipids was tested as a partial replacement for fish meal (FM) in diets of juvenile cobia. The effects of increasing dietary levels of SPH on the survival, weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR), nitrogen retention efficiency (NRE) and daily feed intake (DFI) of cobia with initial body weight of 11.9 g were evaluated. Four isoproteic (from 431.1 to 439.7 g kg−1) and isoenergetic (20 825–21 347 MJ kg−1) diets were formulated to contain 0 (Control), 120, 240 or 360 g kg−1 of dietary CP derived from SPH. Survival, WG, SGR, FCR, NRE and DFI ranged from 90 to 100%, 40.2–56.5 g, 4.7–6.1% day−1, 1.04–1.54, 26.3–44.0% and 4.7–6.0% fish−1 day−1 respectively. Survival and DFI were not affected by the dietary treatments. On the other hand, fish fed the control diet and the one containing 120 g kg−1 SPH had higher WG, SGR and FCR. Nitrogen retention efficiency was significantly higher for fish fed diets 0 and 120. It is concluded that up to 120 g kg−1 of SPH in cobia diets can be used with no significant effects on feed utilization and fish performance.  相似文献   

13.
An 84-day feeding trial was conducted to study the effect of replacing dietary fishmeal with dried chicken viscera meal (CVM) on the growth (net biomass gain, specific growth rate, SGR), feed acceptability, feed conversion ratio (FCR), protein efficiency ratio (PER) and carcass composition of Clarias batrachus fingerlings. Triplicate groups of fingerlings with mean initial body weight of 13.35 g were fed on six iso-nitrogenous and iso-lipidic diets. The control diet (CVM0) used marine by-catch fishmeal as the sole source of animal protein. In the other five diets (CVM100–CVM500), 20–100% of fishmeal was substituted by dried CVM at 20% increments. The highest body weight gain, SGR and PER, and the lowest FCR were observed in fish fed a diet containing 300–500 g CVM kg−1. The fish accumulated increasing quantities of lipids and decreasing levels of ash in their carcasses with increasing levels of dietary CVM.  相似文献   

14.
To determine the digestible lysine requirement for pacu juveniles, a dose–response feeding trial was carried out. The fish (8.66 ± 1.13 g) were fed six diets containing the digestible lysine levels: 6.8, 9.1, 11.4, 13.2, 16.1 and 19.6 g kg?1 dry diet. The gradual increase of dietary digestible lysine levels from 6.8 to 13.2 g kg?1 did not influence the average values of the parameters evaluated (P > 0.05). The increase of dietary digestible lysine level to 16.1 g kg?1 significantly improved weight gain (WG), specific growth rate (SGR), protein productive value (PPV), protein efficiency rate (PER), and apparent feed conversion rate (FCR), but was not different from fish fed diets containing 19.6 g kg?1 lysine. Fish fed diets containing 16.1 and 19.6 g kg?1 digestible lysine showed lower body lipid contents than fish in the other treatments. The digestible lysine requirement as determined by the broken‐line model, based on average WG values, was 16.4 g kg?1. The other essential amino acid requirements were estimated based on the ideal protein concept and the value determined for lysine.  相似文献   

15.
An 8‐week feeding trial was conducted to determine the effects of dietary methionine level on juvenile black sea bream Sparus macrocephalus. Fish (initial body weight: 14.21 ± 0.24 g) were reared in eighteen 350‐L indoors flow‐through circular fibreglass tanks (20 fish per tank). Isoenergetic and isonitrogenous diets contained six levels of L‐methionine ranging from 7.5 to 23.5 g kg−1 of dry diet in 3.0 g kg−1 increments at a constant dietary cystine level of 3.1 g kg−1. Growth performance and feed utilization were significantly influenced by dietary methionine levels (P < 0.05). Maximum weight gain (WG), specific growth rate (SGR), feed efficiency ratio, protein efficiency ratio and protein productive value (PPV) occurred at 17.2 g methionine kg−1 diet, beyond which they showed declining tendency. Protein contents in whole fish body and dorsal muscle were positively correlated with dietary methionine level, while muscle lipid content was negatively correlated with it. Apparent digestibility coefficients (ADCs) of dietary nutrients were significantly affected by dietary treatments except for ADCs of crude lipid. Fish fed the grade level of methionine demonstrated a significant improvement in whole‐body methionine content, total essential amino acids (∑EAA), total non‐essential amino acids (∑NEAAs) and ∑EAA/∑NEAA ratio (P < 0.05). Regarding serum characteristics, significant differences were observed in total cholesterol, glucose and free methionine concentration (P > 0.05), while total protein level and triacylglycerol concentration kept relatively constant among treatments (P < 0.05). Analysis of dose response with second‐order polynomial regression on the basis of either SGR or PPV, the optimum dietary methionine requirements of juvenile black sea bream were estimated to be 17.1 g kg−1 of diet (45.0 g kg−1 methionine of protein) and 17.2 g kg−1 of diet (45.3 g kg−1 methionine of protein) in the presence of 3.1 g kg−1 cystine, respectively.  相似文献   

16.
Two feeding trials of 8 and 10 weeks each were conducted to quantify the dietary lysine requirement of juvenile striped bass, Morone saxatilis. Diets in both experiments contained approximately 420 g crude protein kg–1 and 13.4 MJ digestible energy (DE) kg?1. L ‐Lysine‐HCl was added to the basal diet to yield five and six treatments in the two experiments. Diets in the first experiment were determined to contain 9.2, 14.1, 14.6, 19.9 and 21.0 g available lysine kg?1 on a dry‐matter basis. Diets in the second experiment were determined to contain 14.8, 18.1, 21.3, 24.5, 27.6 and 30.9 g available lysine kg?1 on a dry‐matter basis. Weight gain, specific growth rate (SGR), feed conversion ratio (FCR), and apparent nitrogen utilization (ANU) were significantly (P < 0.05) improved by increasing dietary lysine concentrations to approximately 20 g kg?1 of diet. Least‐squares regression analysis of weight gain and SGR in the first experiment indicated a minimum dietary lysine requirement of 20.1 ± 2 g kg?1 dry diet. Least‐squares regression analysis of the same criteria measured in the second experiment yielded the following estimates of dietary lysine requirements (g kg?1 dry diet): 19.8 ± 2.3 for weight gain, 21.7 ± 1.5 for SGR, 23.7 ± 3.5 for FCR and 18.6 ± 1.3 for ANU. From these results the minimum recommended dietary lysine requirement for optimal growth of juvenile striped bass is approximately 21 g kg?1 dry diet which equates to 49 g kg?1 dietary protein or 1.57 mg kJ?1 DE. Although higher than that reported for hybrid striped bass, this requirement level is similar to those reported for many other fish species.  相似文献   

17.
An 84‐day feeding trial was conducted to study the effect of different levels of dietary protein, 250 (P25), 300 (P30), 350 (P35), 400 (P40) and 450 g (P45) kg?1 dry matter (DM) on growth, feed intake, feed utilization and carcass composition of bagrid catfish Horabagrus brachysoma fingerlings. Triplicate groups of fingerlings with mean initial body weight of 2.2 g were fed the experimental diets twice daily, till satiation, in 150‐L tanks supplied with flow‐through freshwater. Daily dry matter intake by the fingerlings decreased significantly (P < 0.05) when fed P25 diet, containing 250 g protein kg?1. The highest body weight gain, specific growth rate (SGR) and protein efficiency ratio (PER), and the lowest feed conversion ratio (FCR) were observed in fish fed 350 g protein kg?1 diet. The fish fed with P45 diet had the lowest (P < 0.05) carcass lipid content. The polynomial regression analysis indicates that H. brachysoma fingerlings require 391 g dietary crude protein kg?1 diet.  相似文献   

18.
Triplicate groups of Indian catfish, Heteropneustes fossilis (Bloch), fingerlings (average wet weight 3.55 ± 0.03 g) were fed semi-purified diets containing six levels of biotin (0, 0.086, 0.26, 0.86, 2.5 and 4.3 mg kg−1 diet) for 15 weeks. After 42 days of feeding, fish fed the control (no biotin) diet had developed severe deficiency signs characterized by convulsions, heavy mortality, listlessness, poor feed conversion and feed intake, dark skin colour, tetanus and weight loss. None of these signs was seen in fish fed biotin-supplemented diets. Among all the biotin-supplemented diets, percentage weight gain was significantly highest for fish fed the diet supplemented with 0.26 mg of biotin kg−1 and significantly lowest for fish fed the diet supplemented with 0.086 mg of biotin kg−1. Feed conversion ratio (FCR) and protein efficiency ratio (PER) patterns were similar to that of percentage weight gain. The carcass protein and lipid contents were influenced by the dietary biotin up to fish fed 0.26 mg of biotin kg−1. Significantly higher body biotin content, liver pyruvate carboxylase and acetyl CoA carboxylase activities were observed in fish fed biotin-supplemented diets than in fish fed the control diet. Broken-line analyses showed that the optimum dietary requirement for biotin for maximal weight gain, body biotin content, liver pyruvate carboxylase and acetyl CoA carboxylase activities was about 0.25 mg kg−1. Associated liver pyruvate carboxylase and acetyl CoA carboxylase activities for normal growth ranged from 105 to 120 units mg−1 protein and from 9 to 11 units mg−1 protein respectively.  相似文献   

19.
A 10‐week feeding experiment was conducted to determine the optimum dietary protein requirement of juvenile obscure puffer (Takifugu obscurus). Six isoenergetic (20 MJ kg?1 gross energy) diets were formulated to contain graded levels of 34%, 38%, 42%, 46%, 50% or 54% crude protein (as dry matter basis). The results showed final body weight, weight gain and specific growth rate (SGR) increased significantly with increasing protein levels up to 42% and then decreased thereafer. Second‐order polynomial regression analysis (y = ?0.0024x2 + 0.1788x ? 1.3196, R2 = 0.9032) indicated a maximum SGR at protein level of 37%. Feed conversion ratio (FCR) decreased with increasing levels of dietary protein up to 42% and increased thereafter. Second‐order polynomial regression analysis (y = 0.0054x2 ? 0.4351x + 10.391, R2 = 0.753) indicated a minimum FCR at protein level of 40%. Protein efficiency ratio (PER) of fish fed the 34%, 38% and 42% diets was significantly higher than that of fish fed the 46%, 50% and 54% diets, and broken‐line analysis indicated PER tended to decrease when dietary protein level was higher than 40%. Generally, whole body lipid content, total cholesterol, low‐density lipoprotein cholesterol and triacylglycerol decreased with increasing levels of dietary protein. Fish fed the 42% protein diet showed the highest essential amino acids (histidine, isoleucine, leucine, lysine and threonine) and non‐essential amino acids (aspartic acid and glutamic acid) in muscle. Based on the second‐degree polynomial regression analysis of SGR and FCR and broken‐line analysis of PER, the optimal dietary protein level of obscure puffer is estimated to be between 37% and 40% (% as dry matter basis).  相似文献   

20.
Two, 8‐week feeding trials were conducted to compare protein‐sparing capability of dietary lipid in herbivorous grass carp (Ctenopharyngodon idella) and omnivorous tilapia (Oreochomis niloticus × O. aureus). Utilizing a 2 × 3 factorial design, experimental diets containing two levels of crude protein (380 and 250 g kg−1) and three levels of lipid (0, 40 and 100 g kg−1) were formulated for use in both feeding trials. Growth performances showed better response of both fish fed 380 g kg−1 protein diet than those fed 250 g kg−1 protein diet. Despite the dietary protein level, weight gain (WG), specific growth ratio (SGR), feed conversion ratio (FCR) and protein efficiency ratio were much higher (P < 0.05) for grass carp fed 40 g kg−1 lipid diet than those fed 100 g kg−1 lipid diet; however, there were no significant differences in tilapia fed the two diets. The feed intake of grass carp fed lipid‐free diet was the lowest, but it tended to decrease with increase in dietary lipids in tilapia. Lipid retention (LR) was negatively correlated with dietary lipid concentration of both fish. Viscerosomatic index (VSI), hepatosomatic index (HSI), intraperitoneal fat ratio (IPF) and whole‐body and liver lipid content positively correlated with dietary lipid concentration of both fish. Plasma parameters and liver enzymes activities were also positively correlated with dietary lipid concentration of both fish. Liver lipid contents were higher and enzymes activities were lower in grass carp when compared with tilapia. These data suggested that there was no evidence of a protein‐sparing effect of dietary lipids in grass carp. Tilapia has relatively higher capacity to endure high dietary lipid level compared to grass carp.  相似文献   

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