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1.
Growth, feed conversion, and nutrient retention efficiencies of African catfish fingerling, Clarias gariepinus (5.22 ± .07 cm; 8.22 ± 0.03 g), fed diets with varying levels of protein were assessed by feeding seven casein/gelatin based isocaloric (17.62 kJ/g GE) experimental diets with graded levels of dietary protein (20%, 25%, 30%, 35%, 40%, 45%, and 50% of the diet) to triplicate groups of fish to apparent satiation for eight weeks. Effects of feeding these diets on live weight gain (LWG%), feed conversion ratio (FCR), protein efficiency ratio (PER), protein retention efficiency (PRE%), and energy retention efficiency (ERE%) were assessed. Maximum LWG% (867%), PER (2.01), highest PRE (32%), ERE (69%), best FCR (1.39), and maximum body protein were recorded in fish fed diet containing 35% protein. On the basis of the second-degree polynomial regression analysis of the above response variables, it is recommended that the inclusion of protein in the range of 34.4%–39.6% is optimum for maximizing growth potential, feed conversion, and nutrient retention in African catfish fingerling, Clarias gariepinus.  相似文献   

2.
Two experiments were conducted to ascertain the utilization of different carbohydrate sources and different forms of starch present in bagrid catfish (Mystus nemurus) fry. The nutritional quality and starch forms of cornstarch, dextrin, broken rice, and sago flour were evaluated in a 4 × 2 factorial design. All diets were formulated to be isonitrogenous (400 g kg?1 crude protein) and isolipidic (150 g kg?1 crude lipid), fed to triplicate groups of bagrid catfish fry (initial weight 6.04 ± 0.04 g). Growth studies, enzymatic response and postprandial plasma glucose were observed. A two‐way anova (P > 0.05) analysis of the data obtained showed that the final body weight, specific growth rate (SGR) and food conversion ratio (FCR) were significantly affected by carbohydrate source, but not significantly affected by starch form. Fish fed broken rice and corn starch had similar SGR and FCR compared to fish fed with dextrin and sago flour. The postprandial plasma glucose trend in fish fed with corn starch and broken rice showed a gradual increase while sago flour and dextrin‐fed fish peaked at 2 and 3 h, respectively. Lipogenic enzyme (G6PDH) activity were more pronounced than gluconeogenic enzyme (ME) in M. nemurus irrespective of carbohydrate source and starch form. Therefore, we suggest that raw broken rice and corn starch are suitable carbohydrate sources in the M. nemurus diet.  相似文献   

3.
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   

4.
The effects of different tank background colours (green, black and white) on the growth performance and body coloration of juvenile river cafish, Pangasius hypophthalmus, were examined in this study. The experimental fish with an initial body weight (BW) 0.13 ± 0.05 g and total length (TL) 2.54 ± 0.37 cm were used, and groups of 15 fish per tank were randomly distributed. The experiment was conducted for 20 days as a triplicate for each treatment. Survival, growth in BW, body weight gain (BWG), total length (TL), total length gain (TLG), specific growth rate (SGR), condition factor, feed conversion ratio (FCR), swimming speed, body coloration and stress response were evaluated. River catfish reared in white and green tanks attained significantly higher BW, BWG, TL, TLG and SGR compared to the black tank. The white tank attained significantly better FCR compared to the black tank. River catfish showed the most active swimming behaviour in the green tank (5.49 ± 1.32 cm/s) while the least in the white tank (3.37 ± 0.93 cm/s). Body coloration of river catfish in the black tank showed almost pure black body coloration (75.59 ± 9.08), followed by the green tank (126.23 ± 17.46) and the white tank (148.19 ± 10.51). However, there was no significant difference in the stress level of river catfish reared in white and black tanks and insignificant to those reared in the green tank. The findings in this study showed that the white and green background colour tanks can be used for promoting growth of river catfish culture while the black background colour tank can enhance body coloration that is suitable as ornamental fish.  相似文献   

5.
A comparative study was conducted on growth and protein requirements of channel catfish, Ictalurus punctatus, and blue catfish, Ictalurus furcatus. Four diets containing 24, 28, 32, or 36% protein were fed to both channel (initial weight 6.9 g/fish) and blue (6.6 g/fish) catfish for two growing seasons. There were significant interactions between dietary protein and fish species for weight gain and feed conversion ratio (FCR). No significant differences were observed in weight gain of channel catfish fed various protein diets, whereas higher protein diets (32 and 36%) resulted in better weight gain in blue catfish than lower protein diets (24 and 28%). No consistent differences were observed in the FCR of channel catfish fed various levels of dietary protein, whereas significantly higher FCRs were noted in blue catfish fed the 24 and 28% protein diets compared with fish fed 32 and 36% protein diets. Regardless of dietary protein levels, blue catfish had higher carcass, nugget, and total meat yield, and higher fillet moisture and protein, but lower fillet yield and fillet fat. Regardless of fish species, fish fed the 36% protein diet had higher carcass, fillet, and total meat yield than fish fed the 28 and 32% protein diets, which in turn had higher yields than fish fed the 24% protein diet. It appears that blue catfish can be successfully cultured by feeding a 32% protein diet.  相似文献   

6.
Juvenile scup, Stenotomus chrysops, 0.5–1.5 g weight were fed three different commercial diets for six weeks to determine growth rates. Diets were hand-distributed to triplicate groups of 30 fish, four times a day. Survival for all treatments was 93%. The diets used were INVE Aquaculture NRD marine diet (NRD), Skretting Feed Products Gemma starter feed (Gemma), and Salt Creek Progression fish starter diet (Progression). While all diets supported good growth, after 6 weeks scup fed the NRD diet were of significantly greater length and weight (P?<?0.05) than fish fed the other diets. The effects of each diet on fish growth were significantly different from each other (P?<?0.05), with final live weight (g), total length (mm), relative growth rate (RGR), and daily weight gain (DWG) measurements higher for fish fed the NRD diet. Scup fed the Gemma diet were of significantly greater length and weight than fish fed the Progression diet. The specific growth rate (SGR) of scup fed either the NRD or Gemma diets were not significantly different; however, both of these diets produced fish with significantly higher SGR than those fed the Progression diet. Feed conversion ratios (FCR) of scup fed either the NRD or the Gemma diets were significantly lower than the FCR of fish fed the Progression diet. SGR values were 6.6%, 6.3%?and 5.6%/day, and FCR values were 1.03, 1.11, and 1.31 for fish fed the NRD, Gemma, and Progression diets, respectively. RGR values were 1,439%, 1,212%, and 895%, and DWG values were 0.33 g, 0.27 g, and 0.20 g/day for scup fed the NRD, Gemma, and Progression diets, respectively.  相似文献   

7.
A nutrition trial with striped catfish (Pangasianodon hypophthalmus) juveniles was undertaken to evaluate the effect of replacing dietary fishmeal (FM) protein with corn gluten meal (CGM). A diet with FM as the main protein source was used as the control diet (FM). Five experimental diets (approximately 320 g kg?1 crude protein) were formulated to progressively replace 20% (CGM20), 40% (CGM40), 60% (CGM60), 80% (CGM80) and 100% (CGM100) of FM protein. Fifteen fish per tank (initial weight 11.2 ± 0.6 g) were randomly distributed into 18 80‐litre fibreglass tanks connected to a closed recirculation system (temperature 30.3 ± 1.0 °C). The diets were tested in triplicate for 12 weeks. The final weight and specific growth rate (SGR) of fish fed diets CGM20, CGM40 and CGM60 were not significantly different compared to fish fed the FM diet. Feed intake (FI) tended to decrease with increasing dietary CGM level. Striped catfish fed FM, CGM20 and CGM40 had significantly lower feed conversion ratio (FCR) compared with fish fed CGM80 and CGM100 (P < 0.05). The protein efficiency ratio (PER) of fish fed the CGM80 and CGM100 diets was significantly lower than those of all other treatments (P < 0.05). Total ammonia‐nitrogen (TAN) excretion increased with elevated dietary CGM inclusion. The viscerosomatic index (VSI) of fish fed the CGM80 and CGM100 diets were significantly higher (P < 0.05) than those of fish fed the other treatments. The crude lipid content in the final body composition of the striped catfish was elevated significantly with increasing dietary CGM levels. Fish fed the CGM80 and CGM100 diets displayed haematocrit levels significantly lower (P < 0.05) than those fed the other diets. The haemoglobin content in fish was significantly higher in fish fed CGM20 and lower at CGM100 compared to fish fed the FM diet. The results of the present trial indicated that the optimum level of FM protein replacement with CGM determined by quadratic regression analysis was 25.1% on the basis of maximum SGR.  相似文献   

8.
A feeding trial was performed to determine the effect of a commercial source of Yucca schidigera and Quillaja saponaria extracts (Nutrafito Plus®), in practical diets, on striped catfish Pangasianodon hypophthalmus growth, feed utilization, body composition, total ammonia‐nitrogen (TAN) excretion and haematological parameters. Four experimental diets were supplemented with Nutrafito Plus® at 0%, 0.01%, 0.02% and 0.03% (diets: control, N01, N02 and N03 respectively). Three replicate groups of striped catfish, with initial mean weight of 1.78 ± 0.05 g, were fed one of the four diets for 12 weeks. The specific growth rate (SGR) and final weight of fish fed diet N03 was significantly higher (P < 0.05) than fish fed the other dietary treatments. The growth performance of fish fed diets N01 and N02 were not significantly different compared to fish fed the control diet. Striped catfish fed diet N03 had improved feed conversion ratio (FCR), net protein utilization (NPU) and protein efficiency ratio (PER) than the control (P < 0.05). The inclusion of the high dietary level of Yucca schidigera and Quillaja saponaria, diet N03, reduced TAN compared to all groups. Dietary inclusion of Yucca schidigera and Quillaja saponaria at all levels investigated did not affect the whole body proximate composition of the striped catfish (P > 0.05). The packed cell volume (PCV) and haemoglobin level in fish fed diet N03 was significantly higher than in the fish fed the control diet. The present study demonstrates that dietary inclusion of Yucca schidigera and Quillaja saponaria induced positive effects on growth performance and haematological parameters and decreased TAN excretion in striped catfish.  相似文献   

9.
This study was performed to evaluate the effect of replacing fish meal with local by‐products on Clarias gariepinus growth performance, feed utilization and body composition. A control diet contained 50% of fish meal. In four other diets, fish meal was partially replaced by vegetable and animal protein blend composed of sunflower oil cake, soybean oil cake, groundnut oil cake, bean meal, chicken viscera and blood meal. The study was conducted in a recirculating water system at a mean temperature of 23.6°C. The five test diets were compared with a commercial diet developed for African catfish. All diets were balanced to be equal in gross energy (19 kJ g−1) and crude protein (40%). The experimental groups were fed in triplicate for 8 weeks, increasing fish weight from about 6.2 g at start to 52.3 g in the end. Best specific growth rate (SGR=3.4), feed efficiency (FE=1.3) and protein efficiency ratio (PER=3) were obtained with the control diet (diet 50% fish meal), although there were no significant differences between the group of fish fed the control diet and those fed diets based on groundnut oil cake or bean meal, whereas SGR (2.17), FE (0.85) and PER (1.95) were significantly (P<0.01) lower in fish fed diet containing sunflower oil cake. No significant differences (P<0.05) were found in fish fed commercial diet and diets containing bean meal or groundnut oil cake. Groundnut oil cake or bean meal can thus replace at least 50% of fish meal in the diet of Clarias fingerlings without amino acid supplementation. Because of its economic importance and its potential in animal nutrition sunflower oil cake is still an interesting feed ingredient, but its efficiency should be improved by various processing techniques. African catfish can utilize efficiently a diet with low percentage of animal protein without growth reduction.  相似文献   

10.
Tropical catfish, Mystus nemurus (C. & V.) (25.89 ± 0.7 g) were stocked semi-intensively in 0.03-ha earthen ponds at the rate of 10 000 ha”-1 and fed six iso-energetic practical diets ranging from 27% to 50% protein for 8 weeks. Each diet was fed in three replicate ponds twice daily to satiation. Experimental fish were also reared extensively, in control ponds, without supplementary feed. Fish fed the 42% protein diet had the highest standing crop, weight gain and protein utilization values and the differences from other diets were statistically significant (P > 0.05). Protein efficiency ratio (PER) decreased as dietary protein increased. The experiment indicated that natural food organisms contributed to some degree if not significantly to the catfish production. Weight gain, food conversion ratio (FCR). PER and SGR (specific growth rate) indicated that a 42% protein diet with digestible protein-to-energy ratio (D/E) of 27.57 mg kj_1 produced maximum growth in the static pond system.  相似文献   

11.
The present study was based on a 2 × 4 factorial design with two levels of dietary protein (33% or 37% CP) and four phytase levels (0.0, 750, 1,000, and 1,250 FTU/kg diet). African catfish, Clarias gariepinus (B.) (10.7 ± 0.4 g), were distributed into earthen ponds (100 m2 surface area per each) at a density of 4.5 fish per m2. Fish were fed on the experimental diets up to satiation twice a day for 3 months. Another experiment with the same treatments was conducted in 45-L tanks for 2 months to evaluate nutrient retention and digestibility. The growth and production of African catfish fed phytase-enriched diets were higher than those fed the control diet. The highest fish performance and production was observed with fish fed 37% CP enriched with a 1,200 FTU/kg diet of phytase. Feed intake was significantly affected by supplemental phytase alone, where it increased significantly as dietary phytase increased at both protein levels, resulting in similar FCR values (1.31–1.46). Additionally, the maximum values of protein efficiency ratio, protein retention, and phosphorus retention were obtained at 33% CP with phytase levels of 750–1,000 FTU/kg diet. It is also noticed that organic matter, protein, and phosphorus were more digestible in fish fed a 37% CP diet with high phytase levels. These results suggest that the optimum performance and production of African catfish were observed at a 37.0% CP diet enriched with a phytase level of 1,200 FTU/kg diet.  相似文献   

12.
Two experiments (Experiment I and 11) were conducted to evaluate the effects of dietary soybean meal (SBM) with or without supplementation of methionine on the growth performance of the southern catfish Silurus meridionalis. Fish were fed isonitrogenous (48% crude protein) and isoenergetic (20 KJ/g gross energy) diets for 8 wk in a recirculating rearing system. In Experiment I, six diets containing 0.0,11.6, 23.1, 34.7, 46.3, and 57.9% solvent‐extracted SBM as replacement of 0% (control), 13%, 26%, 39%, 52% and 65% fish meal (FM) protein were formulated to examine the effects of dietary SBM on growth performance. Each of the six diets was randomly fed to triplicate tanks, and each tank was stocked with 10 fish (average initial weight 23.78 ± 0.09 g). Fish fed the diets with 13%, 26%, and 39% protein from SBM had significantly higher or similar specific growth rate (SGR) compared with the control group. However, SGR in fish fed the diets with 52% and 65% protein from SBM was significantly lower than other groups (P < 0.05). These results showed that 39% of FM protein could be replaced by SBM protein in diets of the southern catfish without significantly reducing growth. In Experiment II, seven diets were formulated to examine the effects of supplemental methionine on the growth performance of this fish (initial weight of 19.73 ± 0.36 g) fed diets at the two SBM substitution level (SL) for replacing 39% or 52% FM protein. The control diet was the same as that (0% SL) in Experiment I. Three methionine levels (0.00%, 0.12%, or 0.26% at 39% SL, 0.00%, 0.21%, or 0.33% at 52% SL) were separately supplemented to represent two endogenous controls (no methionine supplementation), and to produce diets with the same methionine content as that found in either the body carcass of this fish or the control diet (0% SBM protein), respectively. The results showed that there were no significant differences in feeding rate, digestibility and SGR between fish fed the diets with and without supplementation of methionine at 39% SL. However, supplementation of methionine at 52% SL results in significantly higher SGR and feed efficiency (FE) than that of fish fed the diet without supplementation (P < 0.05). It is suggested that the endogenous methionine content in the diet at 39% SL could meet the requirement for the growth, but is insufficient at 52% SL. The results of the present study indicate that methionine is one of the limiting factors in SBM‐based diets to growth of the southern catfish, and supplementation of methionine into diets containing a high content of SBM could improve the growth performance of this fish.  相似文献   

13.
A 12‐week feeding trial was carried out in concrete tanks to examine complete and partial replacement (75%) of fish meal (FM) with poultry by‐product meal (PBM), meat and bone meal (MBM) and soybean meal (SBM) in practical feeds for African catfish Clarias gariepinus. Triplicate groups of fish (initial body weight ranged from 90.33 to 93.93 g fish−1) were fed seven isonitrogenous and isocaloric diets of 20% digestible protein and 300 kcal 100 g−1 of digestible energy. The control contained 25% herring meal, whereas in the other six diets, PBM, MBM and SBM replaced 75% or 100% of the FM. Final body weight (FBW) and specific growth rate (SGR) of the fish fed diets containing PBM (75% and 100%), SBM (75% and 100%) and MBM (75%) were all higher, but not significantly different than those for fish fed the control diet. Replacing 100% of the FM by MBM significantly lowered FBW and SGR. Concerning whole body composition, there were no significant differences in ash and gross energy content of whole‐body among fish; fish fed diets containing PBM‐100% recorded significantly lower protein content compared with the control diet, while fish fed diet SBM‐100% recorded significantly lower moisture content compared with the control diet. Also fish fed diets SBM‐100% and PBM‐75% recorded higher lipid and gross energy contents compared with the control diet. The study revealed that satisfactory growth and feed utilization responses could be achieved through the replacement of FM by PBM, SBM and MBM in the diet of African catfish.  相似文献   

14.
The study was undertaken to evaluate the growth performance and feed utilization of African catfish, Clarias gariepinus, fed six diets (D) in which fishmeal (FM) was gradually replaced by a mixture of local plant by‐products. In diets 1 and 2, FM (250 g kg?1) was replaced by sunflower oil cake (SFOC). In diets 3 and 4, FM (250 and 150 g kg?1, respectively) was replaced by SFOC and bean meal (BM) while FM was totally substituted by a mixture of groundnut oil cake (GOC), BM and SFOC in diets 5 and 6. Sunflower oil cake was cooked, soaked or dehulled in order to determine the appropriate processing techniques for improving the SFOC nutritive value and to evaluate the apparent digestibility coefficient (ADC) values of the alternative diets. No significant differences were observed for daily feed intake, weight gain, specific growth rate (SGR) and feed efficiency (FE) among fish fed D1, D2, D3 (250 g kg?1 FM), D4 (150 g kg?1 FM) and D6 (0 g kg?1 FM). The highest SGR (3.2% per day) and FE (1.2) were achieved in fish fed D3, and the lowest in fish fed D5 (0% FM), suggesting a maximum acceptable dietary concentration of hulled SFOC below 250 g kg?1 in African catfish juveniles. Protein efficiency ratio ranged from 2.2 to 3.2 for all dietary treatments and was positively influenced by FM inclusion. African catfish were able to digest plant protein very efficiently in all diets tested. ADC of protein ranged from 88.6 to 89.5%, while ADC of energy was relatively low for diets containing hulled sunflower oilcake (71–74%) and high when sunflower oilcake was dehulled (78.6–81.3%). Similarly, ADC of dry matter was higher when sunflower was dehulled (72.1%) when compared with crude SFOC (60.5%). Soaking increased ADC values for neutral detergent fibre (NDF), dry matter, energy, protein and amino acids (AA). There were no significant differences in protein ADCs (88–90%) with increased levels of dietary vegetable ingredients. Both soaking and dehulling of sunflower before incorporation helped in the reduction of NDF, antitrypsin and tannins. Digestibility of all AA was generally high, greater than 90% for both indispensable and non‐indispensable AA. Based on the data obtained, it was possible to totally replace menhaden fish meal with a mixture of vegetable proteins (72% of total dietary protein) when diets contained a relatively low percentage of animal protein (28% based on blood meal and chicken viscera meal) without negative effects.  相似文献   

15.
Juvenile channel catfish, Ictalurus punctatus (Rafinesque), blue catfish, I. furcatus (Lesueur), and their reciprocal Fl hybrids were fed practical diets containing 25% and 45% protein during a 10-week trial to determine the effects of genotype, dietary protein level and genotype X diet interactions on growth, feed conversion ratio (FCR), fillet proximate composition and resistance to the bacterium Edwardsiella ictaluri. Rankings of genotypes (best to worst) for absolute weight gain, percentage weight gain and FCR were: channel, channel female X blue male, blue, and blue female X channel male for the 25% protein diet; and channel, channel X blue, blue X channel, and blue for the 45% diet. Diet did not affect growth or FCR of channel catfish, but growth and FCR were better for blue catfish and both hybrids fed the 25% diet compared to those fed the 45% diet. Channel catfish additive genetic and maternal effects were favourable, and heterosis was negative for growth and FCR. After adjusting for effects of fish size, genotype had no effect on fillet composition. Fillet protein was higher for all genotypes, and fillet lipid was lower for blue catfish and hybrids fed the 45% diet than for fish fed the 25% diet. Genotype X diet interactions observed for growth, FCR and fillet lipid appeared to be a result of poor palatability of the 45% diet to blue catfish and hybrids. Survival (76-93%) and antibody levels (0.10-0.24 OD) after exposure to E. ictaluri at the end of the feeding trial were not affected by genotype or diet. Hybridization of blue catfish and channel catfish would not be an effective method for improving the traits measured for the fish strains and diets used in this study.  相似文献   

16.
The value of toasted Mucuna utilis seed meals was investigated in this study by evaluating the nutritional profile and the utilization of the processed seeds in isonitrogenous (35% CP) and isocaloric diets (17 kJ g?1) for African catfish Clarias gariepinus (Burchell 1822). Toasting the M. utilis seed significantly reduced the levels of tannins, phytate, trypsin, and hemagglutinin in the seeds. However, protein, gross energy, arginine, histidine, and valine were increased (P ≤ 0.05). The processed seed was then used to formulate five experimental diets by progressively increasing its inclusion (by 50 g kg?1) from zero up to 200 g kg?1. A sixth diet was also formulated with raw M. utilis included at 200 g kg?1 to determine the efficacy of the processing method applied in this study. Fifty fingerlings of C. gariepinus (2.02 g ± 0.08) stocked in 18 hapas measuring 1 × 1 × 1 m3 were then fed the diets for 56 days. The growth of C. gariepinus fingerlings was significantly improved by the addition of the toasted M. utilis seed meal. However, fish fed the diet containing 200 g kg?1 of raw M. utilis had poor growth with higher mortality (35%). Estimation of the feeding cost using the diets revealed reduction in production cost of fish with the inclusion of toasted M. utilis seed meal. It was concluded that toasting significantly improved the nutritional quality of this unconventional feedstuff, allowing better utilization at up to 200 g kg?1 inclusion level in the diet of African catfish C. gariepinus.  相似文献   

17.
A plant protein mixture (PPM) was tested to replace fish meal (FM) in diets for juvenile Nile tilapia, Oreochromis niloticus. Fish averaging (±SD) 3.7±0.14 g were divided into 15 groups. Three groups were fed each of five isonitrogenous (33.6%) and isocaloric (4.7 kcal g?1) diets replacing 0%, 25%, 50%, 75% and 100% of the FM protein with similar percentages of PPM (PPM0, PPM25, PPM50, PPM75 or PPM100 respectively). The PPM consisted of 25% soybean meal, 25% cottonseed meal, 25% sunflower meal and 25% linseed meal, and 0.5% of both methionine and lysine were added to each diet except for the control. After 16 weeks of feeding, the fish fed diets PPM75 and PPM100 exhibited growth performance not differing significantly from the fish fed control diet. PPM substitution of up to 75% of the FM protein did not result in differences in the apparent protein digestibility compared with the control, whereas in the PPM100 group digestibility was significantly lower than in the other groups, except for fish fed the PPM75 diet. The incorporation of PPM in diets did not significantly affect whole‐body dry matter, protein, fat or energy compared with the control. The cost–benefit analyses of the test diets indicated that the PPM diets were economically superior to FM. The protein from PPM can completely replace the FM protein in the diets for Nile tilapia, based on the results of this study.  相似文献   

18.
A study was conducted to evaluate low‐protein traditional or alternative diets for pond‐raised hybrid catfish, Ictalurus punctatus × Ictalurus furcatus. Three 24% protein diets containing decreasing levels of soybean meal (30, 20, and 15%) and increasing levels of cottonseed meal and corn germ meal were compared with a 28% protein control diet. Hybrid catfish fingerlings (mean initial weight = 71 g/fish) were stocked into 20 earthen ponds (0.04 ha) at a density of 14,826 fish/ha with five ponds per dietary treatment. Fish were fed once daily to apparent satiation for a 191‐d growing season. There were no significant differences in total diet fed, net yield, weight gain, feed conversion ratio (FCR), survival, or fillet proximate nutrient composition among dietary treatments (P ≥ 0.10). However, regression analysis showed for fish fed 24% protein diets there was a linear increase in FCR as soybean meal levels decreased (P = 0.06). Compared with fish fed the 28% protein control diet, fish fed 24% protein diets had lower carcass and fillet yield. Results demonstrate a 24% protein alternative diet containing 20% soybean meal may be substituted for 28% protein diets for hybrid catfish during food fish production.  相似文献   

19.
In this experimentation, corn gluten (CG) and pea meal (PM) were tested as potential protein sources in hybrid sturgeon ‘AL’. One hundred and twenty‐eight hybrid sturgeons ‘AL’ (Acipenser naccarii × Acipenser baeri) (initial body weight 364.8 ± 4.5 g) were utilized with four experimental diets and four replicates each; the experimental design was 4 × 4. Four isonitrogenous [crude protein=40% dry matter (DM)] and isoenergetic (gross energy=20 MJ kg?1 DM) diets were formulated containing different levels of CG with or without PM and tested against a control diet that was fish meal (FM) based. Diets were as follows: CG55 contained 55% of corn gluten; diet CG55PM25 contained 55% CG and 25% PM; diet CG45PM25 contained 45% of corn meal and 25% of PM; and diet FM was control, based on FM. Fish fed with the PM diet showed lower values of feed conversion ratio (FCR) and specific growth rate (SGR) (FCR=4.53 ± 2.51 in the CG55PM25 diet; FCR=4.09 ± 1.45 in the CG45PM25 diet; SGR=0.20 ± 0.07 in the CG55PM25 diet; SGR=0.19 ± 0.11 in the CG55PM25 diet). The results of tissue proximate composition confirmed the results obtained from productive traits. This study indicates that CG meal but not PM could be utilized as a substitute of FM in hybrid sturgeon ‘AL’ nutrition.  相似文献   

20.
Juvenile channel catfish (5.6 g/fish) were fed a basal diet that contained major protein (soybean meal, cottonseed meal) and energy (ground corn grain, wheat middlings) ingredients that were derived from plant sources. The basal diet was supplemented with three levels of crystalline taurine to provide 1, 2 and 5 g/kg taurine. In addition, a fifth diet that contained 80 g/kg menhaden fishmeal formulated with the same plant‐source ingredients was included as the positive control diet. Fish were fed the five diets once daily for 12 weeks. Weight gain was highest in catfish fed taurine at 2 g/kg (47.8 g/fish) compared to catfish fed the control basal diet (40.8 g/fish) and 80 g/kg fishmeal diet (41.1 g/fish) (p < .05). Among the taurine‐supplemented diets, weight gain was lowest in catfish fed taurine at 5 g/kg. Feed conversion ratio (FCR) was significantly improved in fish fed diets supplemented with taurine at 2 g/kg compared to all other treatments (p < .01). Survival during the growth study ranged from 98.0 to 99.0% (p > .05) for all treatments. The results suggest taurine supplementation to juvenile channel catfish may improve weight gain and FCR.  相似文献   

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