Evaluation of the nutritive value of Leucaena leucocephala leaf meal, inoculated with fish intestinal bacteria Bacillus subtilis and Bacillus circulans in formulated diets for rohu, Labeo rohita (Hamilton) fingerlings

Nine isonitrogenous (35% crude protein approximately) and isocaloric (18.37 kJ g^?1) experimental diets (RLL20–BCFL40) were formulated with either raw or treated (inoculated with fish intestinal bacteria) Leucaena leucocephala leaf meal at 20%, 30% and 40% levels replacing other ingredients partially from a fish meal based reference diet (RD). Two specific strains of fish intestinal bacteria, Bacillus subtilis (isolated from Cyprinus carpio) and B. circulans (isolated from Oreochromis mossambicus) having extracellular cellulolytic and amylolytic activities, were used to inoculate Leucaena leaf meal for 15 days at 37°C. The crude fibre, cellulose and hemicellulose contents and the antinutritional factors, tannin, phytic acid and mimosine in the leaf meal decreased due to inoculation. However, free amino acids and fatty acids increased in the treated leaf meal. The response of rohu, Labeo rohita, fingerlings fed the experimental diets for 80 days was compared with fish fed a RD. Both the inclusion level and type of Leucaena leaf meal in diets significantly affected the growth performance of rohu. Fish fed diets containing inoculated Leucaena leaf meal performed better in comparison with those with the RD. On the basis of growth response, feed conversion ratio, protein efficiency ratio and apparent net protein utilization, diet formulated with 30%Leucaena leaf meal inoculated with B. circulans resulted in the best performance of rohu fingerlings followed by diet with 40%B. subtilis inoculated Leucaena leaf meal. The apparent protein digestibility (APD) was better in fish fed diets containing B. circulans inoculated leaf meal. An increasing level of raw Leucaena leaf meal was associated with a decrease in the carcass protein content of rohu fingerlings. The activity of α‐amylase increased with the increasing level of treated leaf meal in diets. Cellulase activity increased with increasing level of inclusion of raw leaf meal, and was comparatively lower in fish fed diets with treated leaf meal. Activities of protease and lipase were higher in fish fed the RD. The results showed that it is possible to incorporate Leucaena leaf meal inoculated with enzyme‐producing fish intestinal bacteria in carp diets up to 40% level of inclusion.     

Improvement of nutritive value of sesame oilseed meal in formulated diets for rohu,Labeo rohita (Hamilton), fingerlings after fermentation with two phytase-producing bacterial strains isolated from fish gut

Eight isonitrogenous (approximately 35 % crude protein) and isocaloric (17.58 kJ g^?1) diets incorporating raw and fermented sesame oilseed meal replacing other feed ingredients including fishmeal at 10, 20, 30 and 40 % levels by weight into a fishmeal-based reference diet (RD) were fed to rohu, Labeo rohita, fingerlings (mean initial weight 3.19 ± 0.09 g) for 80 days. Two phytase-producing bacterial strains (LF1 and LH1 of Bacillus licheniformis) isolated from the foregut and hindgut regions of adult L. rohita were used for fermentation of oilseed meal for 15 days at 37 ± 2 °C. Fermentation of sesame seed meal was effective in significantly reducing the crude fibre content and anti-nutritional factors such as tannins and phytic acid and enhancing available free amino acids, free fatty acids and mineral concentration. In terms of growth, feed conversion ratio and protein efficiency ratio, 30 % fermented oilseed meal incorporated diet resulted in a significantly (P < 0.05) better performance of rohu fingerlings. In general, growth and feed utilization efficiencies of diets containing fermented oilseed meal were superior to diets containing raw meal. The apparent digestibility of protein, lipid, ash and minerals (phosphorus, calcium, manganese, copper and iron) was significantly (P < 0.05) higher in fish fed diet containing 30 % fermented oilseed meal in comparison with those fed RD. The maximum deposition of protein in the carcass was recorded in fish fed the diet containing 30 % fermented seed meal.     

Evaluation of raw and hydrothermically processed Prosopis juliflora seed meal as supplementary feed for the growth of Labeo rohita fingerlings

Hydrothermically processed Prosopis juliflora (PJ) seed meal as a supplementary diet for Labeo rohita is found to be rich in protein (330 g kg^?1) having antinutritional factors in permissible limits and containing essential amino acids adequately except lysine, methionine and cysteine. Ten iso‐nitrogenous and iso‐energetic diets with crude, soaked and autoclaved seed meal at 20%, 35% and 50% replacement of fish meal were tested (D1–D9, respectively). The growth of fish (weight gain, specific growth rate, feed conversion ratio and protein efficiency ratio) fed diet D4 (soaked seed meal at 20% replacement) was higher among the test diets, but lower than reference diet (RD). Diets with 50% seed meal resulted in lowering of growth, carcass composition, digestive enzyme activity and digestibility compared to test diets at 20% and 35% inclusion levels in the respective groups. Hydrothermically processed seed meal improved the growth compared to unprocessed one, though not up to RD level. This could be because of amino acid imbalance and presence of non‐starch polysaccharides in seed meal. Looking to the easy availability and its nutritional quality, processed PJ seed meal can be incorporated in carp diet at lower inclusion level.     

The potential of deoiled sal (Shorea robusta) seed meal as a feedstuff in pelleted feed for Indian major carp, rohu, Labeo rohita (Hamilton), fingerlings

Ten isonitrogenous (350 g kg^1-crude protein) diets incorporating raw and soaked deoiled sal (Shorea robusta) seed meal at 200, 300,400, 500 and 600 g kg^?1 into a fish-meal-based diet were fed to rohu, Labeo rohita (Ham.), fingerlings for 60 days and fish performance was studied. Tannin from raw salseed meal could be reduced from 34 to 7 g kg^?1 by soaking in water for 16 h at room temperature. In terms of growth response, food conversion ratio and protein efficiency ratio, a diet containing 200 g kg^?1 soaked salseed meal resulted in significantly (P < 0.01) the best performance of the fish. Apparent protein digestibility (APD) values decreased with increasing level of oilseed meal. Carcass protein was highest in fish fed diets containing 200 g kg^?1 soaked salseed meal. The results showed that deoiled salseed meal can be incorporated in carp diets up to 200 g kg^?1 and 300 g kg^?1 in raw and treated forms respectively.     

Effect of dietary L-carnitine supplements on growth and body composition of fingerling rohu, Labeo rohita (Hamilton)

Rohu, Labeo rohita (Ham.), fingerlings (average wt 3.38 g) maintained in 25 m² cement tanks were fed fish-meal-based, 300 g kg⁻¹ protein diets containing different levels (0, 0.25, 0.5, 0.75 and 1.0 g kg⁻¹) of L -carnitine in triplicate over a period of 126 days. Fish that received 0.5 g kg⁻¹ carnitine showed significantly higher growth than those fed the basal diet or the rest of the carnitine diets. Fat digestibility, food conversion efficiency and protein efficiency ratio were better in carnitine-fed fish; however, viscerosomatic and hepatosomatic indices decreased. Muscle proximate composition was affected as a result of carnitine treatment. The results of the present study demonstrate a positive effect of carnitine on the growth and body composition of rohu.     

Soybean meal replacement by roquette (Eruca sativa Miller) seed meal as protein feedstuff in diets for African Catfish, Clarias gariepinus (Burchell 1822), fingerlings

Apparent digestibility coefficient (ADC) values for mechanically extracted meal derived from roquette (Eruca sativa) seeds were obtained. The digestibility of dry matter (DM), protein and energy was measured using an inert marker in the diets and by faeces collection using the dissection method. Soybean meal and roquette meal had similar ADC values for protein and energy. Roquette seed meal was thereafter evaluated as a protein source in diets (400‐g crude protein, 120‐g crude lipid and 18.00 MJ gross energy kg^?1 DM) fed to African catfish, Clarias gariepinus, fingerlings (10.4±0.4 g) to apparent satiation twice daily for 70 days. The test diets contained roquette seed meal as replacement for soybean meal protein in a control diet, providing 20%, 40% or 60% of the total protein. Catfish mortality was low (<10%) and not diet related. Substituting soybean meal protein with roquette seed meal protein providing 20% of total protein did not affect weight gain, growth response, feed conversion ratio, protein utilization or carcass composition of catfish. Catfish growth was, however, retarded and feed was poorly utilized only when roquette seed meal provided above 20% of total protein, caused by reduced energy digestibility, deficiencies in some essential amino acids and presence of antinutritional factors. Livers of catfish fed high dietary levels of roquette seed meal showed severe histological abnormalities.     

Improvement of quality of sesame Seasamum indicum seed meal protein with supplemental amino acids in feeds for rohu Labeo rohita (Hamilton) fingerlings

An 8-week feeding trial was conducted in a static indoor rearing system to examine the effects of partial substitution of fish meal (FM) protein with sesame seed meal protein with and without supplemental amino acids in diets for rohu Labeo rohita fingerlings (average weight 3.82 ± 0.05 g). Before incorporation into diets, sesame Seasamum indicum seed meal was fermented with lactic acid bacteria Lactobacillus acidophilus in order to reduce/eliminate the antinutritional factors tannin and phytic acid present in it. Twelve experimental diets (diets D1 to D12) were formulated replacing the FM protein from a reference diet with sesame seed meal protein at different levels (four sets of diets, of which each set of three diets contained 30%, 40% and 50% replacement of FM protein by sesame seed meal protein respectively). Diets D1 to D3 were not supplemented with any amino acid. Lysine was supplemented to diets D4 to D6. Diets D7 to D9 were supplemented with methionine–cystine (together), and diets D10 to D12 contained lysine and methionine–cystine (together). Lysine and methionine–cystine were added to the diets at 5.7% and 3.1% of dietary protein respectively. The groups of fish fed diets without any supplemental amino acids had significantly lower percentage weight gain, specific growth rate (SGR) and higher feed : gain ratio (FGR) than the groups of fish fed on other experimental diets. The addition of lysine and methionine–cystine to the diet in which 50% of FM protein was replaced by sesame meal protein (diet D12) significantly improved fish weight gain and FGR. The percentage live weight gain and SGR values differed significantly (P < 0.01) from each other in the fish fed diets D10 to D12, which were supplemented with all three amino acids. The results of the present study suggest that rohu fingerlings can effectively utilize the supplemented amino acids and that sesame seed meal protein can replace up to 50% of FM protein in the diets for rohu if the sesame seed meal is properly processed (fermented) and supplemented with deficient amino acids.     

The apparent total and nutrient digestibility of sal seed (Shorea robusta) meal in rohu, Labeo rohita (Hamilton), fingerlings

The apparent digestibility of both raw and treated (16 h soaked in water) deoiled salseed (Shorea robusta) meal by Labeo rohita (Hamilton) fingerlings was evaluated at 20, 30, 40, 50 and 60% levels of incorporation for each, using fish meal based feed as the reference diet. The tannin content from salseed meal could be reduced from 3.4% (in raw salseed meal) to 1.1, 0.9, 0.8 and 0.7% by soaking in water at room temperature for 30 min, 1 h, 2 h and 16 h, respectively. The digestibility of dry matter, protein, lipid and ash declined with increasing levels of inclusion of raw and soaked salseed meal. The diets containing soaked salseed meal resulted in better digestibility of nutrients at all levels of inclusion as compared to those obtained with diets that incorporate raw salseed meal. The results indicate that deoiled salseed meal can be incorporated upto a level of 30% in processed (16 h soaking in water) condition by reducing tannin.     

Effect of feeding frequency on growth, survival and feed utilization in fingerlings of Catla catla (Hamilton), Labeo rohita (Hamilton) and Cirrhinus mrigala (Hamilton) in outdoor rearing systems

Fingerling rearing of Indian major carps, Catla catla, Labeo rohita and Cirrhinus mrigala, were conducted in concrete tanks under a polyculture system at a density of 0.3 million fry ha^?1 to evaluate the effect of one, two or three feedings per day on growth, survival and feed utilization. Fry were fed with formulated supplementary diet at 10% of biomass per day during the first 15 days, followed by 8% in the next 15 days and 6% thereafter, for 60 days. Feeding of fish three times daily led to higher growth (103.9±8.5 mm/10.3±2.4 g) than those feeding twice (100.2±4.8 mm/9.9±1.5 g) or once (97.2±9.8 mm/9.4±2.1 g) daily, although the values were not significantly different (P>0.05). Survival rate ranging between 72.3% and 75.1% also did not vary significantly (P>0.05) among the treatments. However, higher feeding frequencies resulted in better feed utilization as evident from decreasing feed conversion ratio values. The present study suggested requirement of a higher feeding frequency for rohu compared with catla and mrigal.     

Utilization of electron beam irradiated Jatropha kernel meal in the diet of Labeo rohita (Hamilton, 1822) fingerlings

Defatted Jatropha kernel meal (DJKM) was irradiated through electron beam radiation at 25 kGy (IJKM). After irradiation, PEs and phytate were decreased by 36.67% and 55.27%, respectively, with slight reduction in total hydrolysed amino acids in IJKM. A 45‐day feeding trial was conducted to evaluate the utilization of irradiated Jatropha kernel meal (IJKM) in the diet of rohu (Labeo rohita) fingerlings. Five isonitrogenous (300 g/kg CP) and isoenergetic (15 MJ/kg GE) diets such as T0 (control, without IJKM), T5 (50 g/kg IJKM), T10 (100 g/kg IJKM), T15 (150 g/kg IJKM) and T20 (200 g/kg IJKM) were prepared and fed to fish of respective treatments. Fish fed diets containing T15 and T20 groups exhibited significantly lower (p < .05) weight gain, FCE, PER, ANPU, HSI, ISI, survival rate, nutrient and energy digestibility, than the other groups. Fish of higher IJKM fed groups (T15 and T20) also showed lower muscle moisture, protein, ash and higher muscle lipid content. The liver catalase and SOD activities significantly decreased in the higher IJKM fed groups. It is concluded that IJKM (irradiated by 25 kGy electron beam) can be incorporated up to 100 g/kg in carp feed with the replacement of 33% soybean meal and 28% ground nut oil cake without compromising growth performances of Labeo rohita.     

Effects of dietary inclusion of the beta-adrenergic agonist, salbutamol, on growth performance and whole-body composition of rohu Labeo rohita (Hamilton) fingerlings fed diets containing two protein levels

A 60-day feeding experiment was conducted in the laboratory to evaluate the effect of oral administration of the beta-adrenergic agonist (BAA), salbutamol, on growth, nutrient utilization and whole-body composition of rohu Labeo rohita (Hamilton) fingerlings (average weight 5.51 ± 0.07 g) acting as a repartitioning agent in intermediary metabolism and redistributing nutrients for muscle synthesis. Two diets (diets 30/0 and 40/0) were formulated containing 30% and 40% crude protein to serve as basal diets containing the same ingredient composition. Another four diets (diets 30/3, 30/6, 40/3 and 40/6) were prepared in the same way to contain either 3 or 6 mg kg⁻¹ BAA salbutamol at each protein level making the total of six experimental diets. Rohu fingerlings were fed with the experimental diets in three replicate treatments at a restricted feeding regime equivalent to 2% of body weight (BW) day⁻¹. A significant (P < 0.05) interaction effect was found between dietary protein level and BAA treatment. Dietary incorporation of BAA at both protein levels significantly (P < 0.05) increased growth and nutrient utilization in terms of weight gain (%), specific growth rate (SGR), feed:gain ratio (FGR) and protein efficiency ratio (PER). BAA treatment at the 6 mg kg⁻¹ concentration led to a 12% rise in growth with the 30% protein diet and a 6% rise with the 40% protein diet, above their respective controls (without BAA treatment). However, no significant differences were found by raising the BAA concentration from 3 to 6 mg kg⁻¹. The apparent digestibility values for protein, lipid and energy were only higher with the 30% protein diets containing BAA. At both protein levels tested, BAA exerted a significant (P < 0.05) positive influence on protein retention and a negative influence on lipid retention efficiency, although the differences between the 3 and 6 mg kg⁻¹ BAA diets were not significant. This indicated that BAA acted as a repartitioning agent in suppressing lipid deposition in favour of protein accretion. BAA induced significantly (P < 0.05) higher whole-body protein and lipid relative to the untreated groups. The condition factor improved significantly (P < 0.05) in the BAA-treated dietary groups. The fillet percentage displayed a direct correlation and the frame percentage a negative correlation with BAA concentration in the diets. The results indicate that the BAA, salbutamol, was effective in producing growth enhancement, improved body composition (higher protein and lower lipid accretion) and efficient nutrient utilization at the 3 mg kg⁻¹ dietary incorporation level and thus has a potential for application in formulated diets for the Indian major carp, rohu, under culture conditions.     

In vitro assay of plant protease inhibitors from four different sources on digestive proteases of rohu, Labeo rohita (Hamilton), fingerlings

The in vitro inhibitory effect of protease inhibitors from four seed extracts (soybean, grasspea, black gram and horse gram) on digestive proteases of rohu was assessed by enzyme inhibition assay and substrate sodium dodecyl sulphate‐polyacrylamide gel electrophoresis. High proteolytic activity was detected in the intestinal extract of rohu (Labeo rohita) fingerlings at two different pH ranges (8–8.5 and 10–11). That protein digestion occurs mainly in the alkaline condition in this fish without a stomach is evident from very high trypsin activity (0.95±0.04 benzoyl‐dl ‐arginine‐p‐nitroanilide U mg protein⁻¹) in the intestine. In case of grass pea seed, more than 50% inhibition of alkaline protease activity was recorded when the ratio of inhibitor to enzyme was 9.41 μg U⁻¹. More than 40% inhibition of protease activity was recorded in case of horse gram seed when the ratio of inhibitor to enzyme was 5.51 μg U⁻¹. Black gram at 11.0 μg U⁻¹ and soybean seed proteins at 62.75 μg U⁻¹ resulted in 50% and more than 30% inhibition of digestive protease activity in rohu fingerlings respectively. A plot of the inhibition values obtained by changing the relative concentrations of enzyme/inhibitor resulted in different dose–response curves for different protein sources. The use of substrate gel electrophoresis allowed the visualization of the aforementioned differences in inhibition. Each seed extract produced a characteristic profile of protease inhibition. It is concluded that protease inhibitors present in plant protein sources adversely affect the digestive proteases in fish and hence there is a need to eliminate/reduce the amount of such inhibitors through proper processing before incorporation into aquafeeds.     

Growth and body composition of rohu (Labeo rohita) fed diets containing oilseed meals: partial or total replacement of fish meal with soybean meal

A 56‐day feeding trial was conducted to evaluate growth, feed utilization and body composition of fingerling rohu, Labeo rohita (4.5 ± 0.2 cm; 2.58 ± 0.04 g), fed five isonitrogenous (350 g kg^?1 crude protein) and isoenergetic (15.7 kJ g^?1 metabolizable energy) diets in which the main protein contributors were: diet I, fish meal (FM); diet II, soybean meal (SBM); diet III, groundnut meal (GNM); diet IV, equal amounts of SBM, GNM and canola meal (CM); diet V, equal amounts of FM, SBM, GNM and CM. Fish were stocked in triplicate groups of 25 fish held in 70 L flow‐through tanks (water volume 55 L) and fed twice daily (0900 and 1700 hrs) to apparent satiation. Fish fed diet I exhibited the highest (P < 0.05) values for live weight gain and specific growth rate (% per day). Feed conversion and protein efficiency ratio were better (P < 0.05) in fish‐fed diets I and II. Fish‐fed diet II exhibited lower (P < 0.05) fat and ash contents in carcass. Based on these findings, a 70‐day trial (Experiment II) was conducted with six diets fed under the same conditions where FM was incrementally replaced with SBM. Fingerling L. rohita (6.7 ± 0.4 cm; 4.07 ± 0.02 g) were used for the study. Crystalline l ‐methionine was added to diets containing more than 250 g kg^?1 SBM. This second study showed no significant (P > 0.05) variation in growth, feed utilization and carcass composition for fish fed the different diets. In conclusion, SBM was more effective than GNM or CM, as FM was replaced in feeds for fingerling L. rohita and could completely replace FM when supplemented with methionine and fortified with minerals under the conditions of this study.     

Allozyme variation of hatchery and river populations of rohu (Labeo rohita, Hamilton) in Bangladesh

The genetic variations of rohu (Labeo rohita, Hamilton) sampled from five hatchery populations (Arabpur, Brahmaputra, Comilla, Kishorganj and Natore) and three major river populations (the Halda, the Jamuna and the Padma) were analysed by allozyme electrophoresis. Ten enzymes encoded by 11 loci were screened, and six were polymorphic. Alleles at three loci (Est‐1^*, Gpi‐1^* and Gpi‐2^*) proved variable for hatchery and river populations, and the Mdh‐2^* locus exhibited heterozygous genotypes for river populations only. Polymorphic loci per population (27.3±5.3%), heterozygous loci per individual (15.5±1.2%) and relative gene diversity (0.27±0.08) in river populations were higher than those for hatchery populations (25.5±1.8%, 10.7±1.6% and 0.25±0.01 respectively). Also, the observed heterozygosity (Ho) and expected heterozygosity (He) (0.09±0.03 and 0.14±0.04 respectively) in river populations were higher than those in hatchery populations (0.08±0.01 and 0.11±0.01 respectively). The lower levels of genetic variability in hatchery populations suggested the occurrence of inbreeding and/or genetic drift. The pairwise population differentiation (F_ST) values showed a lower level of genetic differentiation between hatchery and river population pairs. The unweighted pair‐group method with arithmetic mean dendrogram of Nei's genetic distances showed a relationship between the genetic distance and geographic distance. The populations were clustered into three groups: the Padma in one group, the Halda in second group and the Jamuna, including five hatcheries, in the third group. Highly diversified rohu individuals were observed in the Padma and Halda Rivers, whereas less genetically variable individuals were found in the Jamuna River and five hatcheries. These findings can be useful for rohu hatchery propagation to enhance the sustainable aquaculture production.     

Effects of dietary protein and lipid levels on growth, feed conversion and body composition in rohu, Labeo rohita (Hamilton), fingerlings

Twelve experimental diets (D‐1 to D‐12) in a 4 × 3 factorial design (four protein levels: 250, 350, 400 and 450 g kg^?1 and three lipid levels: 50, 100 and 150 g kg^?1) were formulated. Carbohydrate level was constant at 250 g kg^?1. Rohu fingerlings (average wt. 4.3 ± 0.02 g) were fed the experimental diets for 60 days in three replicates at 2% BW  day^?1. Weight gain (%), specific growth rate (% day^?1) and feed gain ratio (FGR) indicated that diets containing 450 g kg^?1 protein and 100 or 150 g kg^?1 lipid (diets D‐11 and D‐12) resulted in best performance, although results were not significantly different from those of diet D‐9 (400 g kg^?1 protein and 150 g kg^?1 lipid). Protein efficiency ratio was highest with diets D‐6 (350 g kg^?1 protein and 150 g kg^?1 lipid) and D‐9 (400 g kg^?1 protein and 150 g kg^?1 lipid) (P > 0.05) and declined with higher and lower protein diets at all levels of lipid tested. Elevated lipid level (50, 100 or 150 g kg^?1) did not produce better FGR in diets containing 400 and 450 g kg^?1 dietary protein (P > 0.05). The combined effects of protein and lipid were evident up to 400 g kg^?1 protein. Growth and FGR showed consistent improvement with increased lipid levels from 50 to 150 g kg^?1 at each protein level tested except with diets containing 450 g kg^?1 protein. Apparent nutrient digestibility (for protein, lipid and energy) did not show significant variation among different dietary groups (P > 0.05). Whole body protein and lipid contents increased significantly (P > 0.05) with dietary protein level. The results of this study indicate that rohu fingerlings are adapted to utilize high protein in diets with varying efficiency. The fish could utilize lipid to spare protein but there is no significant advantage from this beyond the dietary protein level of 350–400 g kg^?1 in terms of growth and body composition.     

Evaluation of Chuni, a commercially available low-cost cattle fodder, in the diet for rohu, Labeo rohita (Hamilton), fingerlings

An 80-day feeding experiment was conducted to evaluate the suitability of incorporation of Chuni, a commercially available low-cost cattle fodder, comprising cereal grains and leguminous seeds, into the practical diets for rohu, Labeo rohita (Hamilton), an Indian major carp, fingerlings (average weight= 6.23 0.15g). Four experimental diets, incorporating Chuni at levels of 10%, 20%, 30% and 40% into a fish-meal-based control diet (35% protein) were formulated. In terms of fish growth, feed conversion, protein efficiency ratio, apparent nutrient digestibility, and protein and lipid deposition in fish muscle, 10%Chuni incorporated diet showed the best performance of fish and was comparable to those with the control diet. However, the growth of fish was lower with higher levels of Chuni incorporation (20% or more), which resulted in poor nutrient digestibility. The present results indicate that Chuni could be used as a component in the supplementary diet for L. rohita fingerlings, partially substituting the fish-meal-based diet up to the extent of 10%, and it this is the first report on the use of Chuni as a dietary ingredient in diets for carp.     

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

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

Evaluation of Cassia fistula meal as a replacement for soybean meal in practical diets of Oreochromis niloticus fingerlings

This study was undertaken to determine the replacement value of Cassia fistula seed meal (CFM) for soybean meal (SBM) in practical diets of Oreochromis niloticus fingerlings. Five practical diets (350 g kg^?1 crude protein) containing 0 g kg^?1 (control), 170 g kg^?1 (diet II), 340 g kg^?1 (diet III), 509 g kg^?1 (diet IV) and 670 g kg^?1 (diet V) substitution levels of CFM for SBM were formulated and fed to triplicate groups of O. niloticus fingerlings (mean initial weight of 10.22 ± 0.03 g) for 70 days. Fish mortality increased linearly with increase in inclusion levels of CFM in the diet. Growth and diet utilization efficiency were depressed in fish fed diets containing CFM at varying inclusion levels. Feed conversion ratio, specific growth rate and protein efficiency ratio of O. niloticus fed on diet containing 170 g kg^?1 substitution level of CFM were similar (P > 0.05) to the control diet. Digestibility of the different diets decreased with increase in inclusion levels of CFM. Fish fed diet containing 670 g kg^?1 CFM had significantly lower carcass protein. However, no significant differences were observed in carcass protein and lipid contents between fish fed the control diets and diet containing 170 g kg^?1 CFM. The most efficient diet in terms of cost per unit weight gain of fish was obtained in 170 g kg^?1 CFM dietary substitution.     

Partial replacement of soybean meal by sesame meal in diets of juvenile Nile tilapia,Oreochromis niloticus L.

An 8‐week feeding trial was conducted to determine the effects of replacing of soybean meal (SBM) with sesame meal (SM) in the diets of Oreochromis niloticus fingerlings. Seven practical diets (33 g kg^?1 crude protein, 19.2 MJ kg^?1 dry diet) containing substitution levels of 0%, 8%, 16%, 24%, 32%, 40% and 48% SM for SBM protein were formulated and fed to triplicate groups of O. niloticus fingerlings (mean initial weight of 8.74 ± 0.12 g). The fish survival rate, hepatosomatic index, viscerosomatic index and condition factor were not significantly affected by the contents of SM in the diets (P>0.05). The final body weight, weight gain (WG), specific growth ratio, feed conversion ratio and protein efficiency ratio of the fish fed the diet containing 16% SM were similar (P>0.05) to that of the fish fed the control diet. Except lipid, digestible contents of dry matter, crude protein, ash, gross energy and individual amino acids decreased while phosphorous increased with increasing SM levels. No significant differences were observed in whole‐body dry matter, ash and lipid contents among all the treatments (P>0.05); crude protein contents between fish fed the control diet and a diet containing 24% SM were also not affected significantly (P>0.05), and the phosphorus content was not significantly different when the SM level was increased to 32% (P>0.05). No significant negative differences were observed in the liver composition between fish fed the control diet and the diet containing 24% SM. The most efficient diet in terms of cost per unit WG of fish was obtained in 8% SM dietary substitution, while no significant differences were found among the 0%, 8% and 16% levels. It was indicated that SM can be utilized in the juvenile Nile tilapia diet to replace about 16% of SBM protein without causing negative effects on growth performance, body composition, liver composition and feed utilization.