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The study aims were to test the effects of partial or total replacement of dietary fish oil (FO) by palm oil (PO) on growth, antioxidant capacity, lysozyme activity, muscle fatty acid composition, and fillet quality of rohu (Labeo rohita) fingerlings. The rohu fingerlings (3.25 ± 0.13 g) were stocked in 18 circular (water volume 55 L) polyvinyl tanks in triplicate groups (30 fish per tank). Six iso-proteic (400 g/kg) and iso-lipidic (97 g/kg) purified diets were formulated in which FO was replaced by 0, 20, 40, 60, 80, and 100% PO (0 PO, 20 PO, 40 PO, 60 PO, 80 PO, and 100 PO). The diets were fed to the fish for 8 weeks, with meals being given at 8:00, 12:00, and 16:00 h. There were no significant (P > 0.05) treatment effects on growth (19.32–22.58 g gain/fish), feed conversion ratio (1.32–1.68), and protein efficiency ratio (1.48–1.89). However, protein retention efficiency was highest (33.25–34.99%) in fish fed the 0 PO and 60 PO diets, and lipid retention efficiency was highest (53.09%) in the fish fed the 100 PO diet. Muscle eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels and n-3/n-6 ratio were highest in fish fed the 100% FO diet and decreased as increasing proportions of FO were replaced by PO. Serum superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and lysozyme activity did not change significantly (P > 0.05) up to 60% replacement of FO with PO. Further replacement of FO with PO (80 PO and 100 PO) resulted in decreased serum antioxidant capacity and lysozyme activity. Although muscle atherogenicity and thrombogenicity indices did not change significantly (P > 0.05) among treatments, the highest hypocholesterolaemic-to-hypercholesterolaemic (H/H) ratio and fillet lipid quality (FLQ) were found in fish receiving the 0 PO (with 100% FO and no PO). H/H and FLQ values did not differ significantly up to 60% replacement of FO with PO but decreased upon further replacement of FO with PO. FO can be replaced by PO to a level of 60% without hampering the growth and fillet quality of fingerling rohu provided with such diets for a period of a few weeks, but the long-term effects of FO replacement remain to be studied. [ABSTRACT FROM AUTHOR]

The dietary folic acid requirement of fingerling Catla catla (3.4 ± 0.17 g; 7.6 ± 0.41 cm) was evaluated by feeding casein–gelatin‐based isonitrogenous (350 g/kg crude protein) and isocaloric (16.72 kJ/g GE) diets containing different concentrations of folic acid (0, 0.2, 0.4, 0.6, 0.8, 1.0, 2.0 mg/kg) to triplicate groups to apparent satiation at 08:00, 12:30 and 17:30 hr for 16 weeks. Absolute weight gain (AWG; 40.07 g/fish), specific growth rate (SGR; 2.25%), feed conversion ratio (FCR; 1.53), protein retention efficiency (PRE; 31.42%) and protein gain (PG; 6.74) improved significantly (p <.05) with increasing folic acid levels up to 0.4 mg/kg diet and then reached a plateau. However, maximum liver folic acid concentration increased up to 0.6 mg/kg diet. Dietary folic acid levels also significantly affected (p <.05) body composition of fish. No significant change (p >.05) in haematological parameters except in fish fed folic acid‐free diet was noted. Antioxidant and immune parameters increased with increasing concentration of dietary folic acid up to 0.4 mg/kg diet. Broken‐line regression analysis of AWG, FCR, PRE, PG, HCT and liver folic acid concentrations of fingerling C. catla against dietary folic acid levels indicated optimum growth, FCR, PRE, PG, HCT and liver folic acid saturation ranging between 0.22 and 0.56 mg/kg diet, respectively. [ABSTRACT FROM AUTHOR]

Seven isonitrogenous (400 g/kg crude protein) and isocaloric (17.89 kJ/g gross energy) purified diets (casein‐gelatin based) with different concentrations of calcium (0, 1, 2, 3, 4, 5 and 6 g/kg) supplemented with calcium lactate at the levels of 0, 5.4, 10.8, 16.3, 21.8, 27.27 and 32.73 g/kg were prepared and fed for 12 weeks to triplicate groups of Heteropneustes fossilis (7.46 ± 0.03 g) to determine the optimum dietary calcium requirement. Analysed values of calcium in the diets were 2.41, 3.82, 4.56, 5.99, 6.71, 7.40 and 8.19 g/kg, respectively. Absolute weight gain, specific growth rate, protein retention efficiency, protein gain and feed conversion ratio of fish fed diets with increasing levels of dietary calcium improved up to 5.99 g/kg and then levelled off. Whole‐body protein, moisture and ash contents improved up to 5.99 g/kg dietary calcium and stabilized thereafter. However, whole‐body fat exhibited reverse pattern and decreased with incremental levels of dietary calcium up to 5.99 g/kg. Whole‐body and vertebrae mineralization was also significantly affected (p < .05) by the increasing dietary calcium levels. Alkaline phosphatase activity improved significantly (p < .05) up to 6.71 g/kg, and no change was recorded beyond this level. Serum calcium and phosphorus concentrations were not influenced (p > .05) by dietary calcium levels. The Ca–P ratio remained static in the whole body, vertebrae and serum. Broken‐line regression analysis of data obtained on growth, mineralization and serum ALP activity against increasing levels of dietary calcium reflected the optimum calcium requirement between 5.77–6.81 g/kg diet. [ABSTRACT FROM AUTHOR]

Dietary biotin requirement of fingerling Channa punctatus (4.52 ± 0.46 g) was estimated by conducting a 16-week growth trial. Fish were fed casein gelatin-based purified diets (450 g/kg crude protein, 18.39 kJ/g gross energy) with seven levels of dietary biotin (0, 0.04, 0.09, 0.47, 1.02, 1.43, and 1.96 mg/kg diet) to triplicate groups near to satiation. Significantly higher absolute weight gain (P = 0.0018), specific growth rate (P = 0.0027), protein gain (P = 0.0016), protein deposition (P = 0.0038), and lower feed conversion ratio (P = 0.0003) were shown in fish fed diet containing 0.47 mg/kg biotin, whereas liver biotin concentration showed a significant improvement (P = 0.0021) with increasing levels of dietary biotin up to 1.02 mg/kg. Broken-line analysis of absolute weight gain, protein gain, and liver biotin concentrations indicated that fingerling C. punctatus require biotin at 0.46, 0.44, and 0.97 mg/kg diet. Based on protein gain, optimum pyridoxine requirement for fingerling C. punctatus is recommended at 0.44 mg/kg diet. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to quantify the dietary thiamin (experiment I) and pyridoxine (experiment II) requirements of fingerling Cirrhinus mrigala for 16 weeks. In experiment I, dietary thiamin requirement was determined by feeding seven casein-gelatin-based diets (400 g kg−1 CP; 18.69 kJ g−1 GE) with graded levels of thiamin (0, 0.5, 1, 2, 4, 8 and 16 mg kg−1 diet) to triplicate groups of fish (6.15 ± 0.37 cm; 1.89 ± 0.12 g). Fish fed diet with 2 mg kg−1 thiamin had highest specific growth rate (SGR), protein retention (PR), RNA/DNA ratio, haemoglobin (Hb), haematocrit (Hct), RBCs and best feed conversion ratio (FCR). However, highest liver thiamin concentration was recorded in fish fed 4 mg thiamin kg−1 diet. Broken-line analysis of SGR, PR and liver thiamin concentrations exhibited the thiamin requirement in the range of 1.79-3.34 mg kg−1 diet (0.096-0.179 μg thiamin kJ−1 gross energy). In experiment II, six casein-gelatin-based diets (400 g kg−1 CP; 18.69 kJ g−1 GE) containing graded levels of pyridoxine (0, 2, 4, 6, 8 and 10 mg kg−1 diet) were fed to triplicate groups of fish (6.35 ± 0.37 cm; 1.97 ± 0.12 g). Fish fed diet containing 6 mg kg−1 pyridoxine showed best SGR, FCR, PR, RNA/DNA ratio, Hb, Hct and RBCs, whereas maximum liver pyridoxine concentration was recorded in fish fed 8 mg kg−1 dietary pyridoxine. Broken-line analysis of SGR, PR and liver pyridoxine concentrations reflected the pyridoxine requirement from 5.63 to 8.61 mg kg−1 diet. Data generated during this study would be useful in formulating thiamin- and pyridoxine-balanced feeds for the intensive culture of this fish. [ABSTRACT FROM AUTHOR]

An 8-week feeding trial was conducted to assess the effects of dietary l-threonine on growth, protein utilization, threonine retention efficiencies, nucleic acid indices and body composition of fingerling Heteropneustes fossilis (6.6 ± 0.1 g; 10.9 ± 0.2 cm). Casein-gelatin based isonitrogenous (38% crude protein; CP) and isocaloric (15.3 kJ g−1 digestible energy; DE) amino acid test diets with six levels of dietary l-threonine (0.75%; 1.0%; 1.25%; 1.5%; 1.75%; 2.0% dry diet) were prepared and hand-fed to quadruplicate groups of fingerling to apparent visual satiation twice daily. Weight gain (WG; 46.3 g fish−1), feed conversion ratio (FCR; 1.98), protein utilization efficiency (PUE; 0.25), threonine retention efficiency (TRE; 0.69), lipid productive value (LPV; 0.45), body protein (18.2%) and RNA/DNA ratio (3.6) of fish fed graded levels of dietary threonine increased significantly ( P < 0.05) up to 1.49% threonine of dry diet. To generate precise information, the WG, RNA/DNA and LPV data were subjected to broken-line and quadratic regression analyses. The two models were superimposed and requirement was determined by establishing the point, where the quadratic curve first intersected the plateau of broken-line. Based on the above mathematical analyses, optimum dietary threonine requirement of fingerling H. fossilis was estimated to range between 1.62% and 1.69% of the diet, corresponding to 4.26-4.44% protein. [ABSTRACT FROM AUTHOR]

Two separate 12 weeks feeding trials were performed to quantify the total sulphur amino acid (TSAA) requirement (experiment I) and cysteine replacement value for methionine (experiment II) of fingerling Catla catla. In experiment I, six casein-gelatin based (33% crude protein; 16.72 kJ g-1 gross energy) diets with graded levels of TSAA (0.56%, 0.81%, 1.06%, 1.31%, 1.56%, 1.81% dry diet) were fed to triplicate groups of fish (3.55 ± 0.06 cm; 0.65 ± 0.02 g) near to satiation. The TSAA requirement was determined by quadratic regression analysis of absolute weight gain (AWG), protein efficiency ratio (PER), feed efficiency (FE), protein gain (PG) and TSAA gain (TSAAG) against dietary TSAA concentrations at 95% maximum response. Above analysis revealed that inclusion of TSAA at 1.28% dry diet (1.22% methionine + 0.06% cysteine), corresponding to 3.87% of dietary protein is optimum. In experiment II, to determine the replacement value of cysteine for methionine, six diets containing 1.28% TSAA determined in experiment I with different ratios of L-methionine and L-cysteine (80:20, 70:30, 60:40, 50:50, 40:60, 30:70) on equimolar sulphur basis were fed to fish (3.65 ± 0.08 cm; 0.67 ± 0.04 g). Broken-line regression analysis of AWG, PER, FE, PG and TSAAG against varying methionine to cysteine ratios yielded the optimum cysteine replacement value at 40.3%. Based on above analysis, it is recommended that inclusion of 1.28% dietary TSAA, corresponding to 3.87% of dietary protein is optimum of which 40.3% could be spared by cysteine. Data generated during this study would be useful in formulating TSAA balanced, cost-effective feeds for the intensive culture of this fish. [ABSTRACT FROM AUTHOR]

A 12-week feeding trial was conducted to determine the dietary threonine requirement of fingerling Indian major carp, Catla catla (3.35 ± 0.11 cm; 0.59 ± 0.06 g). Six casein-gelatin based (33% crude protein; 3.23 kcal g-1 digestible energy) amino acid test diets with graded levels of analysed threonine (0.74%, 0.96%, 1.21%, 1.48%, 1.72% and 1.93% dry diet) were fed to satiation to triplicate groups of fish. Absolute weight gain (g per fish), feed conversion ratio, protein retention efficiency, threonine deposition, RNA/DNA ratio and carcass protein significantly improved with the increase in dietary threonine and peaked at 1.48% of the dry diet. Haematological indices were also found to be best in fish fed at 1.48% threonine diet. Quadratic regression analysis of absolute weight gain, feed conversion ratio, protein retention efficiency, threonine deposition, RNA/DNA ratio, carcass protein, haemoglobin (g dL-1), haematocrit (%) and RBCs (106 × mm-3) at 95% of maximum and minimum response exhibited the threonine requirement of fingerling C. catla between 1.35% and 1.48% dry diet, corresponding to 4.09-4.48% dietary protein. Present finding would be useful in formulating threonine-balanced feeds for the intensive culture of C. catla. [ABSTRACT FROM AUTHOR]

This study aimed at quantifying leucine requirement of fingerling Catla catla [3.75 (mean body length) ± 0.15 (SE) cm, 0.66 (mean body weight) ± 0.04 (SE) g] by conducting a 12-week feeding trial. Six casein- and gelatin-based (33 % crude protein, 14.0 kJ g calculated digestible energy) semipurified diets containing different concentrations of leucine (0.73, 0.97, 1.24, 1.46, 1.74 and 1.97 % dry diet) were fed to triplicate groups of fish to apparent satiation thrice daily at 08:00, 12:30 and 17:30 hours. Maximum absolute weight gain (AWG, 7.45 g fish), protein gain (PG, 1.31 g fish), leucine gain (LG, 85.33 mg fish), RNA/DNA ratio (4.62) and best feed conversion ratio (FCR, 1.51) were recorded at 1.74 % dietary leucine. Hemoglobin, hematocrit and red blood cell counts count were also found to be optimum in fish fed diet with 1.74 % leucine. Quadratic regression analysis at 95 % maximum response of AWG and minimum response of FCR against dietary leucine concentrations reflected the requirement at 1.58 and 1.57 % dry diet, respectively. Based on above results, inclusion of leucine ranging from 1.57 to 1.58 % of the dry diet is recommended for developing leucine-balanced commercial feeds for the intensive culture of C. catla. [ABSTRACT FROM AUTHOR]

Two 12-week experiments were conducted to determine the dietary phenylalanine requirement and tyrosine replacement value for phenylalanine for fingerling Catla catla . In experiment I, phenylalanine requirement was determined by feeding six casein–gelatin based amino acid test diets (330 g kg − 1 CP; 16.72 kJ g − 1 GE) with graded levels of phenylalanine (3.9, 6.4, 8.7, 11.2, 13.8, 16.2 g kg − 1 dry diet) at a constant level (10 g kg − 1 ) of dietary tyrosine to triplicate groups of fish (3.95 ± 0.24 cm; 0.68 ± 0.19 g) near to satiation. Live weight gain (LWG%), specific growth rate (SGR % day − 1 ), feed conversion ratio (FCR), protein retention efficiency (PRE%), phenylalanine retention efficiency (PHRE%) and RNA/DNA ratio responded positively with the increasing concentrations of phenylalanine reaching the highest values at 11.2 g kg − 1 of dry diet. Quadratic regression analysis of LWG, SGR, PRE, PHRE and RNA/DNA ratio at 95% of maximum response against varying levels of dietary phenylalanine exhibited the requirement at 10.3, 10.1, 9.9, 9.7 and 10.6 g kg − 1 dry diet, respectively. The above analysis revealed that inclusion of phenylalanine at 10.1 g kg − 1 of dry diet, corresponding to 594 g kg − 1 of lysine is optimum. In experiment II, six diets with different levels of l -tyrosine (1.9, 3.8, 5.9, 8.1, 9.8, 11.8 g kg − 1 dry diet) with 10.1 g kg − 1 phenylalanine (determined in experiment I) fixed in all the test diets were fed to fish (3.85 ± 0.25 cm; 0.66 ± 0.16 g) to determine the tyrosine requirement under identical conditions. Quadratic regression analysis of LWG, SGR, PRE, PHRE and RNA/DNA ratio at 95% of maximum response against dietary tyrosine concentrations indicated the requirement at 6.3, 6.5, 6.5, 7.1 and 7.3 g kg − 1 dry diet, respectively. Hence, inclusion of tyrosine at 6.8 g kg − 1 of dry diet, corresponding to 378 g kg − 1 of lysine is taken as the tyrosine required for optimum utilization of phenylalanine. Based on above data, a total requirement of phenylalanine and tyrosine for fingerling C. catla was found to be 16.9 g kg − 1 (10.1 g kg − 1 phenylalanine + 6.8 g kg − 1 tyrosine) of dry diet, corresponding to 939 g kg − 1 of lysine. Tyrosine replacement value for phenylalanine was computed to be 37% on molar basis. [ABSTRACT FROM AUTHOR]

A 12-week feeding trial was conducted to determine the dietary valine requirement of fingerlingCatla catla(3.50 ± 0.15 cm, 0.63 ± 0.04 g). Seven casein gelatin-based diets (33% crude protein; 3.34 kcal/g digestible energy) containing graded levels of valine (0.51%, 0.69%, 0.91%, 1.12%, 1.31%, 1.49%, 1.71% dry diet) were fed to triplicate groups of fish to apparent satiation at 08:00, 12:30, and 17:30 h. Absolute weight gain (AWG), feed conversion ratio (FCR), specific growth rate (SGR%), protein efficiency ratio (PER), protein productive value (PPV), valine retention efficiency (VRE), valine gain (VG), energy retention efficiency (ERE), and carcass protein improved significantly (P < 0.05) with the increasing concentrations of dietary valine from 0.51% to 1.12%. Quadratic regression analysis of AWG, PPV, DPD, VG, ERE, and carcass protein at 95% maximum (Y95%max) response against varying levels of dietary valine yielded the requirement at 1.04%, 1.03%, 1.05%, 1.04%, 1.01%, and 0.98% of dry diet, respectively. It is recommended that inclusion of valine at 1.02% of dry diet, corresponding to 3.09% of dietary protein, is optimum in formulating valine-balanced feeds for fingerlingC. catla. [ABSTRACT FROM AUTHOR]

The effects of feeding rates on growth, feed conversion, protein deposition and carcass quality of fingerling Catla catla (3.61 ± 0.03 cm; 0.71 ± 0.04 g) were worked out by conducting a 16-week feeding trial. Fingerlings were fed with a casein-gelatin-based purified diet (40% crude protein CP; 14.95 MJ kg−1 digestible energy; DE) at 1%, 2%, 3%, 4%, 5%, 6% and 7% body weight per day. The absolute weight gain ( AWG; 10.50 g fish−1) and feed conversion ratio ( FCR; 1.41) were highest at the feeding rate of 5% body weight per day. However, protein gain ( PG; 0.36 g fish−1) and carcass protein content attained the maximum values at 4% BW day−1. Quadratic regression analyses of AWG g fish−1 and PG g fish−1 at 95% maximum response indicated that these parameters attained the best values at 4.19% and 3.81% BW day−1. On the basis of the above results it is recommended that the feeding rate in the range of 3.81-4.19% BW day−1 with a P:E ratio of 26.69-27.74 mg protein MJ−1 DE is optimum for maximum growth, efficient feed conversion and best carcass quality in fingerling C. catla. [ABSTRACT FROM AUTHOR]

In order to determine the dietary isoleucine requirement of fingerling catla, Catla catla (4.25 ± 0.15 cm, 0.61 ± 0.04 g), six isonitrogenous (33.0 % crude protein) and isocaloric (13.7 kJ/g digestible energy) amino acid test diets containing casein, gelatin and l-crystalline amino acids with graded levels of isoleucine (0.5, 0.75, 1.0, 1.25, 1.5 and 1.75 % of the dry diet) were prepared. Triplicate groups of fish were randomly stocked in eighteen 70-l indoor polyvinyl circular troughs at a density of 25 fingerling per trough provided with a water flow-through system (1-1.5 l min). The experimental diets were fed to fish to apparent satiation at 08:00, 12:30 and 17:30 h for 12 weeks. Growth of the fish was found to increase with the incremental levels of dietary isoleucine up to 1.25 % of the dry diet. Quadratic regression analysis at 95 % maximum response of absolute weight gain (6.18 g fish), protein productive value (0.32), isoleucine retention efficiency (71.91 g fish), RNA/DNA ratio (4.81) and carcass protein (15.7 %) yielded the optimum isoleucine requirement in the range of 1.13-1.18 % of the dry diet, corresponding to 3.42-3.58 % of dietary protein. Data generated in this experiment would be useful to formulate isoleucine-balanced, cost-effective quality feeds for fingerling catla. [ABSTRACT FROM AUTHOR]

Abstract: Heteropneustes fossilis is distributed in most of the Southeast Asian countries. It is a promising species for aquaculture due to its high protein and iron content, ability to withstand shifts in salinity and temperature, and survival in oxygen depleted water. In view of the above, this study was undertaken to evaluate the effects of varying levels of dietary l-histidine on growth, protein gain, histidine retention, hematological and body composition of this fish so as to optimize the inclusion of histidine in its commercial feeds. Casein-gelatin based isonitrogenous (380gkg−1 CP) and isocaloric (17.9MJkg−1 GE; 15.3MJkg−1 DE) amino acid diets with six different l-histidine levels (5.0, H1; 6.5, H2; 8.0, H3; 9.5, H4; 11.0, H5; 12.5gkg−1dry diet H6) were fed to quadruplicate groups of fingerling Singhi (6.6±0.2g) twice daily at 07:00 and 17:30h to apparent satiation for 8week. Feeding trial was conducted in a flow-through system (1–1.5Lmin−1) at 28°C water temperature. Growth, feed conversion, protein gain and histidine retention of fingerling Singhi were found to increase significantly with the quantitative increase in dietary histidine from 5.0 (H1) to 9.5gkg−1 diet (H4). Hepatosomatic index, condition factor, hematocrit and hemoglobin were significantly affected in fingerling Singhi fed different concentrations of histidine and were also found to be best in fish fed diet H4. Quadratic regression analysis of the above parameters at 95% maximum and minimum plateau indicated that inclusion of histidine at 9.4gkg−1 of the dry diet, corresponding to 24.8gkg−1 dietary protein is optimum in formulating histidine-balanced, cost-effective, commercial feeds for intensive culture of Singhi. [Copyright &y& Elsevier]

A 12-week experiment was conducted to quantify dietary lysine requirement of fingerling Catla catla (3.65 ± 0.05 cm; 0.58 ± 0.02 g) by feeding casein-gelatine-based diets (33.0 % crude protein; 14.3 kJ/g digestible energy) with six levels of l-lysine (1.25, 1.50, 1.75, 2.00, 2.25 and 2.50 % dry diet). The experiment was conducted in eighteen 70-L indoor polyvinyl circular troughs provided with a water flow-through system (1-1.5 L/min). Live weight gain (LWG), feed conversion ratio (FCR), protein deposition (PD), lysine retention efficiency (LRE%) and RNA/DNA ratio were used as the response criteria. Second-degree polynomial regression analysis at 95 % maximum and minimum response of LWG and FCR data exhibited the lysine requirement between 1.8 and 1.9 % dry diet, corresponding to 5.5-5.7 % dietary protein. Regression analysis of PD, LRE and RNA/DNA ratio yielded the requirement between 1.7 and 1.8 % dry diet, corresponding to 5.2-5.5 % dietary protein. Since live weight gain and protein deposition are the key parameters for estimating nutrient requirement, these tools were used to recommend the lysine requirement of fingerling C. catla which ranges between 1.7 and 1.8 % dry diet. Data generated during this study will be useful to formulate lysine-balanced feed for intensive culture of this fish. [ABSTRACT FROM AUTHOR]

Dietary arginine requirement of fingerling Catla catla (3.55 ± 0.05 cm; 0.61 ± 0.02 g) was determined by feeding casein-gelatin-based isonitrogenous (33% crude protein) and isocaloric (3.40 kcal/g digestible energy) amino acid test diets containing six graded levels of l-arginine (1, 1.25, 1.5, 1.75, 2, and 2.25% dry diet) for 12 wk. Maximum absolute weight gain (6.93 g/fish), protein efficiency ratio (2.13), protein deposition (0.36), arginine retention efficiency (78%), and best feed conversion ratio (1.42) were recorded in fish fed 1.75% arginine of the dry diet. Maximum carcass protein (15.57%) and RNA/ DNA ratio (4.79) were also recorded for the group fed 1.75% arginine of the dry diet. Quadratic regression analysis at 95% maximum or minimum response of above growth parameters yielded optimum arginine requirement of fingerling C. catla at 1.67% of the dry diet. On the basis of the above analysis of the growth parameters, it is recommended that the inclusion of dietary arginine at 1.67% of the dry diet is optimum for formulating arginine-balanced, cost-effective quality feeds for the mass culture of fingerling C. catla. [ABSTRACT FROM AUTHOR]

A 12-week feeding trial was conducted to evaluate the effects of varying levels of dietary arginine on growth, feed conversion, protein productive value and carcass composition of fingerling Heteropneustes fossilis (10.11 ± 0.14 cm; 5.87 ± 0.07 g). Casein and gelatin-based isonitrogenous (38% crude protein) and isocaloric (14.72 kJ g digestible energy) amino acid test diets with varying levels of l-arginine (1.00, 1.25, 1.50, 1.75, 2.00 and 2.25 g 100 g of dry diet) were fed to randomly assigned triplicate groups of fish to apparent satiation twice daily at two feeding schedules (08.00 and 17.30 h). Thermal growth coefficient (TGC; 0.86), feed conversion ratio (FCR; 1.97) and protein productive value (PPV; 0.25) were best attained by the group fed diet containing 1.75 g arginine 100 g of dry diet (D4). Carcass protein content also peaked at the above level of dietary arginine whereas carcass lipid showed consistent drop with the increase in dietary arginine level up to 1.75 g 100 g of dry diet. Second-degree polynomial regression analysis at 95% maximum and minimum response of thermal growth coefficient, feed conversion, protein productive value, carcass protein and lipid productive value against varying levels of dietary arginine yielded that dietary arginine in the range of 1.51-1.66 g 100 g of dry diet, corresponding to 3.97-4.37 g 100 g protein is adequate to optimize growth, feed conversion, protein productive value and improve carcass quality in fingerling H. fossilis. [ABSTRACT FROM AUTHOR]

This study was conducted to quantify dietary vitamin C requirement of fingerling, Cirrhinus mrigala, (0.79 ± 0.07 g; 3.51 ± 0.15 cm) by feeding casein-gelatin based purified diets (400 g/kg crude protein; 3.45 kcal/g digestible energy) containing nine levels of vitamin C as l-ascorbyl-2-polyphosphate (0.0, 5, 15, 25, 35, 45, 55, 75, and 95 mg vitamin C equivalent/kg diet) to triplicate groups of fish to apparent satiation for 16 wk. Absolute weight gain (AWG, g/fish), feed conversion ratio (FCR), protein retention efficiency (PRE%), RNA/DNA ratio, hemoglobin (Hb, g/dL), and hematocrit value (Hct%) were taken as the response criteria to determine vitamin C requirement of mrigal. Fish fed diet with 35 mg/kg vitamin C had significantly higher AWG (9.94 g/fish), FCR (1.39), PRE (27.72%), RNA/DNA ratio (4.18), Hb (11.15 g/dL), and Hct (34.44%) values. However, liver vitamin C concentration was found to be higher (64.92 µg/g wet tissue) in diet containing 45 mg vitamin C/kg. Broken-line regression analysis of AWG data estimated the requirement of 35.65 mg/kg, whereas that of the liver vitamin C concentration data projected the requirement to 41.99 mg/kg. [ABSTRACT FROM AUTHOR]

Effects of varying protein-to-energy (P/E) ratios on growth performance, nutrient retention, body composition, and digestive enzyme activities of Singhi, Heteropneustes fossilis (7.90 ± 0.40 g; 9.40 ± 0.20 cm) were evaluated. Six experimental diets (350Low, 350High, 400Low, 400High, 450Low, and 450High) in a 3 × 2 factorial design were formulated to contain three protein levels (350, 400, and 450 g/kg crude protein) and two energy levels (4.07 and 4.54 kcal/g gross energy [GE]) to provide six different dietary P/E ratios (86.1, 77, 98.3, 88, 110.6, and 99 mg protein/kcal GE). The diets were hand-fed to triplicate groups of fish for 84 d to apparent satiation at two feeding frequencies. Live weight gain, feed conversion ratio, protein retention efficiency, energy retention efficiency, somatic indices, and digestive enzyme activities were maximized by the groups fed on 400 g/kg protein with 4.07 kcal/g GE in diet 400Low with a P/E ratio of 98.3 mg/kcal energy. The results indicate that 400 g/kg of dietary protein and 4.07 kcal/g of dietary GE with a P/E ratio of 98.3 mg protein/kcal energy is optimum for achieving efficient growth, feed conversion, and nutrient retention in H. fossilis. [ABSTRACT FROM AUTHOR]

An 8-week feeding trial was conducted in a flow-through system (1-1.5 L min) 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, gross energy). Diets containing graded levels of protein (300, 350, 400, 450, 500 and 550 g kg) 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), specific growth rate (SGR; 1.82%) and best feed conversion ratio (FCR; 1.48) were recorded in fish fed diet containing 450 g kg 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. 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, 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 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. [ABSTRACT FROM AUTHOR]

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 ofl-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. [ABSTRACT FROM AUTHOR]

An 8-week feeding experiment was conducted to quantify the dietary isoleucine requirement of fingerling Indian major carp, Labeo rohita (3.50 ± 0.04 cm; 0.40 ± 0.02 g) using amino acid test diets (400 g kg−1 crude protein; 17.90 kJ g−1 gross energy) containing casein, gelatin andl-crystalline amino acids. Six dietary treatments supplemented with graded levels of isoleucine (7.5, 10.0, 12.5, 15.0, 17.5 and 20.0 g kg−1), in gradations of 2.5 g kg−1 diet, were fed to triplicate groups of fingerlings to apparent satiation divided over two feedings at 07:00 and 17:30 h. Performance of the fish was evaluated on the basis of live weight gain, feed conversion ratio (FCR), protein efficiency ratio (PER), specific growth rate (SGR) and protein productive value (PPV). Statistical analysis of live weight gain, FCR, PER, SGR and PPV reflected significant differences among treatments. Live weight gain and conversion efficiencies were best with isoleucine at 15.0 g kg−1 of diet. Live weight gain, FCR, PER, SGR and PPV data were also analysed using second-degree polynomial regression analysis to obtain more accurate isoleucine requirement estimate which was found to be at 15.9, 15.3, 15.2, 15.8 and 15.7 g kg−1 of dry diet, corresponding to 39.8, 38.3, 38.0, 39.5 and 39.3 g kg−1 of dietary protein respectively. Based on the quadratic regression analysis of the live weight gain, FCR, PER, SGR and PPV, the optimum level of isoleucine for fingerling L. rohita is in the range of 15.2–15.9 g kg−1 of dry diet, corresponding to 38.0–39.8 g kg−1 of dietary protein. Maximum body protein, minimum moisture and fat were noted at 15.0 g kg−1 of dietary isoleucine while the body ash remained constant among all the treatment levels. No mortality was recorded during the duration of the experiment. [ABSTRACT FROM AUTHOR]

An 8-week feeding trial was conducted to evaluate the effects of dietary tryptophan concentration on weight gain and feed efficiencies of fingerling Indian major carp,Cirrhinus mrigala. Six isonitrogenous (40% crude protein) and isocaloric (17.90 kJ g−1) amino acid test diets containing casein, gelatin andl-crystalline amino acids with graded levels ofl-tryptophan (0.06, 0.16, 0.26, 0.36, 0.46 and 0.56 g 100 g−1 dry diet) were formulated. Fish (4.25±0.30 cm, 0.62±0.02 g) were randomly stocked in triplicate groups in 70 L (water volume 55 L) flow-through (1–1.5 L min−1) indoor circular tanks and fed experimental diets at 5% of their body weight/day in two feedings at 08:00 and 16:00 hours. Maximum live weight gain (277%), lowest feed conversion ratio (FCR) (1.50) and highest protein efficiency ratio (PER) (1.66) were measured at 0.36% dietary tryptophan. The relationship between dietary tryptophan levels and weight gain, FCR and PER data were described using second-degree polynomial regression analysis indicating the tryptophan requirement at 0.42, 0.39 and 0.38 g 100 g−1 of dry diet respectively. Whole body moisture decreased with increasing tryptophan up to 0.36%. Significantly (P<0.05) higher protein content was evident in fish fed diet containing 0.36% tryptophan. Body fat increased significantly (P<0.05) in fish fed with different tryptophan concentrations except those fed 0.36% tryptophan where a significantly lower fat content was noted. Significantly (P<0.05) higher ash content was reported at 0.06% and 0.16% tryptophan levels. Survival was 100% in fish fed all the diets except those fed 0.06% tryptophan. Based on the results, diets for fingerlingC.mrigalashould contain tryptophan at 0.38 g 100 g−1 dry diet, corresponding to 0.95 g 100 g−1 dietary protein for optimum growth and efficient feed utilization. [ABSTRACT FROM AUTHOR]

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−1 dietary 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. [ABSTRACT FROM AUTHOR]