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1.
Jatropha curcas (L.) is a multipurpose and drought‐resistant tree, widespread throughout the tropics and subtropics. Its seeds are rich in oil and protein (contains 600–660 g kg?1 crude protein similar to fish meal). It is being promoted as a biofuel plant. Jatropha kernel meal obtained after oil extraction is an excellent source of protein. However, presence of toxic and antinutritional constituents restricts its use in fish and shrimp feed. An 8‐week experiment was conducted to evaluate the nutritional quality of the detoxified Jatropha kernel meal (DJKM) in white leg shrimp (Litopenaeus vannamei). Shrimp (60) with an initial average body weight of 4.46 ± 0.64 g were randomly distributed into three treatments with four replicates and fed isonitrogenous and isoenergetic diets (crude protein 350 g kg?1, crude lipid 90 g kg?1): Control (fish meal‐based protein), JC25 and JC50 (25% and 50% of fish meal protein replaced by DJKM). Higher (P < 0.05) body mass gain, specific growth rate and metabolic growth rate were observed in DJKM‐fed groups than in Control group. However, lower (P > 0.05) feed conversion ratio was observed in DJKM‐fed groups, while protein efficiency ratio exhibited an opposite trend. Protein, ash and gross energy content of the whole shrimp body were higher (P < 0.05) in DJKM‐fed groups compared to Control group. Moisture and lipid content of the whole shrimp body did not differ significantly among the three groups. Cholesterol level in plasma was highest (P < 0.05) in the Control group, followed by JC25 and JC50 groups; all being significantly different. In conclusion, DJKM is a promising fish meal replacer in shrimp diets.  相似文献   

2.
Jatropha curcas is a multipurpose and drought-resistant shrub or small tree widespread all over the tropics and subtropics. Its seeds are rich in oil, and the Jatropha kernel meal obtained after oil extraction is rich in protein. However, presence of toxic and antinutritional constituents restricts its use in fish feed. Jatropha kernel meal was detoxified. Common carp, Cyprinus carpio, fingerlings (15; av. body mass 10.9 ± 0.65 g) were randomly distributed in three groups with five replicates. A 6-week feeding experiment was conducted in a respirometer system to evaluate the growth performance, nutrient utilisation and energy budget. Fish were fed isonitrogenous diets (38% crude protein): control diet (C ontrol group) containing fish meal (FM) protein based protein and two other diets replacing 75% FM protein with detoxified Jatropha kernel meal (DJKM, J atropha group) and soybean meal (SBM, S oybean group). At the end of the experiment, body mass gain, metabolic growth rate, protein efficiency ratio, protein productive value, energy retention, efficiency of metabolised energy for growth and efficiency of energy retention were determined. These parameters were high and statistically similar for C ontrol and J atropha groups and significantly lower (P < 0.05) for S oybean group. Whereas a reverse trend was observed for energy expenditure per g protein retained in fish body. No significant differences were found in heat released, gross energy uptake, metabolised energy intake, metabolisability, energy expenditure, energy expenditure per g protein fed and apparently unmetabolised energy. Conclusively, common carp–fed plant protein (DJKM and SBM) and FM protein–based diets exhibited equal average metabolic rate.  相似文献   

3.
Detoxified Jatropha kernel meal (DJKM) was created through heat and solvent extraction and replaced fish meal (FM) at 0% (Control), 50% (J50), or 62.5% (J62.5) in common carp Cyprinus carpio fingerling (initial mean weight ± SD; 22 ± 0.12 g) diets over 16 weeks. Growth performance and feeding efficiencies were similar (P > 0.05) among groups, but nutrient digestibilities and digestive enzyme activities were significantly higher (P < 0.05) in Control than others. The slightly lower growth and significantly lower nutrient digestibility in carp fed DJKM indicates a need to improve the nutritive value of DJKM as a promising and sustainable FM alternative.  相似文献   

4.
Jatropha curcas kernel meal is rich in protein; however, it is toxic. Two durations of detoxification process were investigated: 30 and 60 min; designated as Ja and Jb, respectively. Common carp fingerlings (252 fish; 3.2 ± 0.07 g) were fed diets: control containing fishmeal (FM); S50, Ja50 and Jb50: 50% of FM protein replaced by soybean meal (SBM), detoxified Jatropha kernel meal (DJaKM and DJbKM); S75, Ja75 and Jb75: 75% of FM protein replaced by SBM, DJaKM and DJbKM. Highest body mass gain, specific growth rate, metabolic growth rate (MGR) and energy production value were observed for the Jb50 group which were statistically similar to that for control group and significantly (P < 0.05) higher than for all other groups. Lowest feed gain ratio was observed in control group, which was statistically similar to than in Jb50 group. Lowest MGR, protein efficiency ratio, protein productive value and lipid production value were observed in Ja75 group. The dry matter and lipid digestibilities were statistically (P < 0.05) highest in control group and lowest in Ja50 group. Protein and energy digestibilities were statistically similar (P > 0.05) for control and Jb50 groups, and these values were highest among the groups. Highest crude protein efficiency was observed in Jb50 group, whereas lowest in Jb75 group. Relative intestinal length and hepatosomatic index were higher in plant protein–fed groups. Intestinal amylase, protease and lipase activities for control group were statistically higher (P < 0.05) than for plant protein–fed groups. Conclusively, performance of Jb50 group was similar to control group and better than other groups and, thus, is recommended as the most optimal diet for common carp fingerlings.  相似文献   

5.
Feeding rainbow trout, Oncorhynchus mykiss (Walbaum), with 1% lupin, Lupinus perennis, mango, Mangifera indica, or stinging nettle, Urtica dioica, for 14 days led to reductions in mortality after challenge with Aeromonas hydrophila. In addition, there was significant enhancement in serum bactericidal activity, respiratory burst and lysozyme activity in the treatment groups compared to the controls. Use of lupin and mango led to the highest number of red blood and white blood cells in recipient fish, with use of stinging nettle leading to the highest haematocrit and haemoglobin values; the highest value of mean corpuscular volume and haemoglobin was in the control groups and those fed with stinging nettle.  相似文献   

6.
Yeast is a potential alternative to fish meal in diets for farmed fish, yet replacing more than 50 % of fish meal results in reduced fish growth. In a 4-week experiment, 15 rainbow trout (Oncorhynchus mykiss) were cannulated and fed three diets each week: 30 % fish meal as a control (FM); 60 % replacement of fish meal protein, on a digestible basis, with Saccharomyces cerevisiae (SC); and 60 % replacement with Wickerhamomyces anomalus and S. cerevisiae mix (WA). Blood was collected at 0, 3, 6, 12 and 24 h after feeding. In the final week, fish were exposed to a 1-min netting stressor to evaluate possible diet–stress interactions. Significant increases in pH, TCO2, HCO3 and base excess were found after fish were fed the SC and WA diets compared with FM, which elevated blood alkaline tides. Yeast ingredients had lower buffering capacity and ash content than fish meal, which explained the increase in alkaline tides. In addition, fish fed the WA diet had significantly reduced erythrocyte area and fish fed SC and WA diets had increased mean corpuscular haemoglobin levels, indicating haemolytic anaemia. Higher levels of nucleic acid in yeast-based diets and potentially higher production of reactive oxygen species were suspected of damaging haemoglobin, which require replacement by smaller immature erythrocytes. Acute stress caused the expected rise in cortisol and glucose levels, but no interaction with diet was found. These results show that replacing 60 % of fish meal protein with yeasts can induce haemolytic anaemia in rainbow trout, which may limit yeast inclusion in diets for farmed fish.  相似文献   

7.
The effects of two probiotics (P1–Lactobacillus acidophilus, Bifidobacterium bifidum and Enterococcus faecium and P2–Bacillus subtilis) supplemented to commercial feed (40% crude protein) on the haematological and immunological parameters of the bullfrog Lithobates catesbeianus were studied. Two doses of each probiotic (5 and 10 g kg?1 of food) were added to the diets and fed to frogs, totalling five treatments over 112 days. Haematological analyses consisted of total and differential leucocyte counts, erythrocyte and thrombocyte counts, haematocrit, haemoglobin levels and RBC indices (mean corpuscular volume, mean corpuscular haemoglobin – and mean corpuscular haemoglobin concentration) and the immunological parameters included phagocytic capacity and phagocytic index of peritoneal phagocytes. The results showed that the probiotics did not significantly influence any of the haematological parameters measured. However, immunological assays showed that the probiotics had an immunostimulating effect. The greatest effects were seen with probiotic P1 fed at a dose of 10 g kg?1 of diet and probiotic P2 fed at 5 g kg?1 of diet.  相似文献   

8.
Detoxified Jatropha protein isolate (DJPI), prepared from Jatropha seed cake was hydrolysed using Alcalase 2.4L FG. Both DJPI and hydrolysed DJPI (HDJPI) were evaluated as a fish meal (FM) replacement in common carp (Cyprinus carpio L.) diets. The peptide concentration in HDJPI was determined using matrix‐assisted laser desorption ionization‐time of flight mass spectrometer (MALDI‐TOF). Twenty‐two peptides with molecular mass ranging from m/z 906.455 to 1774.943 Da were identified. Fingerlings (45; av. wt. 10.1 ± 0.4 g) were randomly distributed in five groups with three replicates. An 8‐week feeding experiment was conducted to compare the nutritional quality of the HDJPI, DJPI and FM. Fish were fed on iso‐nitrogenous diets: control (FM based protein), J50 (50% of FM protein replaced by DJPI), J75 (75% of FM protein replaced by DJPI), JH50 (50% of FM protein replaced by HDJPI) and JH75 (75% of FM protein replaced by HDJPI). Growth performance was higher for FM fed group compared with the other groups, while nutrient utilization parameters were similar for control and J50 groups and superior (P < 0.05) to J75 and both the HDJPI fed groups. No variation (P > 0.05) was observed in blood albumin and hepatosomatic index among all different groups. Blood urea nitrogen, calcium, sodium and potassium ions in the blood were similar among all five groups.  相似文献   

9.
A direct non‐parametric method was used to calculate reference (physiological) haematology values for farmed 10–12‐month rainbow trout of the Kamloops strain (mean weight: 330±131 g) with respect to red blood cell counts (RBCc), haematocrit values (Hct), haemoglobin concentrations (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentrations (MCHC). The fish in the selected reference group (n=798) were given dry pelleted diets that contained 37–47% crude protein, 7–18% crude fat and 108–300‐mg vitamin E, 1.08–5‐mg folic acid, 0.018–0.05‐mg vitamin B12, 48–64.5‐mg iron, 4.5–8.4‐mg copper and 0.18–0.24‐mg selenium supplied per kg of diet. Ethoxyquin and butylhydroxytoluol were used to protect the fat component against oxidation. The fish were kept at a stocking density of 50kg per cubic metre in tanks provided with running freshwater (dissolved oxygen 8.4–11.5 mg L?1, with O2 saturation of 77–98%) at an ambient temperature of 0.2–16°C. Blood was sampled between September and November at a photoperiod of 9–13 h:11–15 h (light:dark). Reference ranges for the preceding haematological indices were as follows in immature females (males): RBCc, 0.77–1.42T L?1 (T – tera, 1012) (0.98–1.55T L?1); Hct, 0.304–0.502 (0.34–0.546); Hb, 54–93 g L?1 (59–97 g L?1); MCV, 282–469 fL (279–434 fL); MCH, 51–86 pg (47–78 pg); MCHC, 0.15–0.22 (0.15–0.2). In males, values for RBCc, Hct and Hb were significantly higher (P=0.01 and 0.0000 respectively) and those for MCV, MCH and MCHC were significantly lower (P=0.01 and 0.0002 respectively) than in immature females. Nutritional and environmental factors affecting erythropoiesis in trout and some correlations between haematological (RBCc, Hb, Hct) and biochemical indices of the blood plasma (total protein, cholesterol) are discussed.  相似文献   

10.
Jatropha curcas seed meal was fermented with Bacillus licheniformis (LFJSM) and Bacillus pumilus (PFJSM) separately using the solid‐state fermentation. After fermentation, the crude protein and the total hydrolysed amino acid contents were increased in LFJSM and PFJSM, while fibre content, phytic acid, trypsin inhibitor and saponins were decreased. An 84‐day feeding experiment was designed for the nutritional evaluation of LFJSM and PFJSM in Nile tilapia. Seven isonitrogenous (305.47 g kg?1 crude protein) and isocaloric (18.21 MJ kg?1 gross energy) diets were formulated by replacing 0% (control diet), 25% (LFJSM‐25), 50% (LFJSM‐50), 75% (LFJSM‐75) and 25% (PFJSM‐25), 50% (PFJSM‐50) and 75% (PFJSM‐75) of protein from fish meal with LFJSM and PFJSM. The higher weight gain and the best feed conversion ratio were found in fish fed control diet, PFJSM‐25 and PFJSM‐50, which were insignificantly different. Apparent digestibility coefficient values of dry matter, crude protein, lipid and digestible energy reached a plateau in fish fed PFJSM‐25 and PFJSM‐50. No significant differences were found in haematocrit, haemoglobin, serum alternative complement pathway components, alanine aminotransferase and aspartate aminotransferase and triglycerides between the control diet, LFJSM‐25, LFJSM‐50, PFJSM‐25 and PFJSM‐50 treatment groups. Therefore, these findings suggest that up 50% of fish meal can be replaced by PFJSM in Nile tilapia diets.  相似文献   

11.
Jatropha kernel meal was detoxified through the process of solid‐state fermentation using Aspergillus niger fungus. A 60‐d feeding trial was conducted to evaluate the effects of replacing soybean meal (SBM) with fermented Jatropha kernel meal (FJKM) on the hemato‐biochemical and histopathological parameters in Labeo rohita fingerlings (average weight 6.05 ± 0.04 g). A total of 180 fish were randomly distributed in 12 experimental tanks in four dietary groups, namely control (SBM‐based diet), T1 (10% FJKM replacing 33.3% SBM), T2 (20% FJKM replacing 66.7% SBM), and T3 (30% FJKM replacing 100% SBM). There was no significant difference in the red blood cell, white blood cell, hemoglobin, total protein, albumin, globulin, and respiratory burst activity among the various groups, but significantly higher hematocrit value and albumin/globulin ratio were observed in the T2‐fed group compared with the control. No statistical difference was found in serum glucose level of the control and FJKM‐fed groups. Histopathological examination of the intestine and liver indicated no adverse effects in the control and FJKM‐fed groups. Our findings revealed that FJKM can replace 100% SBM protein in the diets of L. rohita fingerlings, without any adverse effects on fish health.  相似文献   

12.
Apparent digestibilities (D) of energy and proximate nutrients were determined in rainbow trout, Oncorhynchus mykiss (Walbaum), by stripping faeces and using Cr2O3 as a marker. When wheat gluten + L-lysine-HCl (WG-lys) as sole source of dietary N were increased stepwise from 324 to 941 g·kg?1, replacing 210 g·Kg?1 fish oil (FO) and 407 g·kg?1 gelatinized corn starch (GCS), D of crude protein rose from 96 to 99% and that of FO was always above 96%. D of GCS was 70% at inclusions up to 210 g·kg?1, but only 41 at 407 g·kg?1. Three by-products of poultry slaughtering and three legume seeds replaced WG at levels of 250 and 500 g·kg?1 in a basal diet of WG-lys, minerals and vitamins. Soy beans had been pressure cooked at one of two intensities, and field beans and fields peas were either untreated or had been autoclaved. D of energy and crude protein was hardly affected by dietary proportion in poultry blood mean (84 and 85%), poultry offal meal (80 and 81%) and incompletely pressure cooked soy beans (82 and 90%); increasing dietary proportions from 250 to 500 g·kg?1 reduced the respective values of feather meal (88–81 and 86–83%), raw (43–32 and 76–70%) and autoclaved field beans (67–57 and 89–86%), as well as raw (47–39 and 86–83%) and autoclaved field peas (65–40 and 91–86%). At the higher proportion, D of energy of completely pressure cooked soy beans was reduced from 91 to 86%, but that of crude protein was constant at 94%.  相似文献   

13.
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.  相似文献   

14.
Jatropha seed cake (JSC) is an excellent source of protein but does contain some antinutritional factors (ANF) that can act as toxins and thus negatively affect the growth and health status of fish. While this can limit the use of JSC, detoxified Jatropha protein isolate (DJPI) may be a better option. An 8-week study was performed to evaluate dietary DJPI to common carp Cyprinus carpio. Five iso-nitrogenous diets (crude protein of 38%) were formulated that consisted of a C ontrol (fish meal (FM) based protein), J 50 or J 75 (50 and 75% of FM protein replaced by DJPI), and S 50 or S 75 (50 and 75% of FM protein replaced by soy protein isolate, SPI) and fed to triplicate groups of 75 carp fingerlings (75; av. wt. ± SD; 11.4 ± 0.25 g). The growth, feeding efficiencies, digestibility, plasma biochemistry, and intestinal enzymes were measured. Results showed that growth performance of fish fed the S 75- or DJPI-based diets were not significantly different from those fed the C ontrol diet, while carp fed the S 50 had significantly better growth than the J 75 diet. Fish fed the J 75 diet had significantly lower protein and lipid digestibility as well as significantly lower intestinal amylase and protease activities than all other groups. However, all plant protein-based diets led to significantly higher crude protein, crude lipid, and gross energy in the body of common carp compared to the control treatment. Plasma cholesterol and creatinine significantly decreased in the plant protein fed groups, although plasma triglyceride as well as the red blood cells count, hematocrit, albumin, globulin, total plasma protein, and lysozyme activity were higher in plant protein fed groups compared to FM fed group. White blood cells, hemoglobulin concentration, alkaline phosphatase and alanine transaminase activities, and glucose level in blood did not differ significantly among treatments. The results suggest that the DJPI is non-toxic to carp and can be used to replace FM in the diets of common carp up to 75%, but further research to potentially reduce some inherent ANF within this protein source, such as non-starch polysaccharides, may improve nutrient utilization.  相似文献   

15.
A dephytinized protein concentrate prepared from canola seed (CPC) was assessed for nutrient digestibility and performance in rainbow trout (Oncorhynchus mykiss). The apparent digestibility coefficients of CPC were: dry matter, 817 g kg?1; crude protein, 899 g kg?1; gross energy, 861 g kg?1; arginine, 945 g kg?1; lysine, 935 g kg?1; methionine, 954 g kg?1; threonine, 893 g kg?1. A 9‐week performance trial assessed 7 diets. Fishmeal provided 940 g kg?1 of the protein in the control diet. Test diets consisted of CPC or water‐washed CPC replacing 500 and 750 g kg?1 of fishmeal protein; and CPC plus an attractant replacing 500 and 750 g kg?1 of fishmeal protein. No significant differences in performance were observed (P > 0.05). A subsequent 9‐week performance trial evaluated the effect of adding CPC into compound diets containing fishmeal/soybean meal/corn gluten meal. Five diets were prepared: fishmeal provided 670 g kg?1 of the protein in the control diet, in the remaining diets CPC was incorporated into commercial‐like trout diets at 100, 200 and 300 g kg?1 replacement of fishmeal protein, the fifth diet included an attractant in the 300 g kg?1 replacement diet. No significant differences in performance were obtained (P > 0.05). These studies show that dephytinized canola protein concentrate has potential to replace substantial levels of fishmeal in diets for carnivorous fish without compromising performance.  相似文献   

16.
A feeding trial was conducted on the effects of methionine hydroxy analog (MHA) and taurine supplementation in diets with high levels of soy protein concentrate (SPC) on the growth performance and amino acid composition of rainbow trout, Oncorhynchus mykiss (Walbaum) comparing with fish meal based diet. The control diet had 520 g kg?1 fish meal. In the methionine deficient diets (5.1 g kg?1), fish meal was replaced by 490 g kg?1 of the SPC in the SPC49 diet. The SPC49 diet was supplemented with either MHA (6 g kg?1) only or a combination of MHA and taurine (2 g kg?1). Fish were fed isoproteic (460 g kg?1) and isolipidic (130 g kg?1) diets for 12 weeks. Growth performance (i.e. weight, feed conversion ratio, and thermal‐unit growth coefficient) was inferior in fish fed the SPC49 diet. MHA supplementation improved growth performance (P < 0.05). No difference was observed when taurine was added to the SPC49 and MHA diet (P > 0.05). Whole‐body taurine contents increased with taurine supplementation, whereas plasma methionine increased with MHA supplementation (P < 0.05). In conclusion, the substitution of fish meal with SPC supplemented with MHA did not negatively impact growth, and the addition of taurine did not improve growth performance in rainbow trout.  相似文献   

17.
A 56‐day growth trial was conducted to determine the amount of fish meal (FM) in rainbow trout (Oncorhynchus mykiss) diets containing 200 g/kg FM as the sole animal protein source; that could be replaced with carinata (Brassica carinata) meal (CM) processed by aerobic conversion (AC, by fungi ssp.) followed by a single wash (ACCM). ACCM replaced 50, 100 and 150 g of FM. Replacement of ≥100 g of FM with ACCM, resulted in reduced (p < 0.01) growth, due to reduced dietary lysine and diet consumption (p < 0.01). Fulton's condition factor K decreased (p < 0.01) with increased FM replacement. FCR (p < 0.01) had an inverse relationship with diet consumption. The trend in FCR was similar to the trend in PER (p < 0.01). Apparent net protein utilization was lower (p < 0.01) for the highest FM replacement diet. There was no effect of FM replacement by ACCM on whole‐body composition or viscera, spleen and liver weights. However, visceral fat increased (p < 0.01) with increased feed consumption. There was no apparent effect of ACCM on hematocrit, haemoglobin or mean corpuscular haemoglobin contents. Results of this study indicate that replacement of ≥100 g of FM by ACCM in low FM/animal (200 g/kg) RBT diets may have been achieved if feed consumption and dietary lysine were similar.  相似文献   

18.
Triplicate groups of gibel carp Carassius auratus gibelio (initial body weight: 5.25 ± 0.02 g) were fed for 8 weeks at 20–25 °C on five isonitrogenous (crude protein: 400 g kg?1) and isoenergetic diets (gross energy: 17 kJ g?1). Meat and bone meal (MBM) or poultry by‐product meal (PBM) were used to replace fish meal at different levels of protein. The control diet contained fish meal as the sole protein source. In the other four diets, 150 or 500 g kg?1 of fish meal protein was substituted by MBM (MBM15, MBM50) or PBM (PBM15, PBM50). The results showed that feeding rate for the MBM50 group was significantly higher than for other groups except the PBM50 group (P < 0.05). Growth rate in the MBM15 group was significantly higher than that in the control (P < 0.05), while there was no significant difference in growth between the control and other groups (P > 0.05). Feed efficiency and protein efficiency ratio in MBM50 was significantly lower while that in MBM15 was significantly higher (P < 0.05). Replacement of fish meal by MBM at 500 g kg?1 protein significantly decreased apparent dry matter digestibility (ADCD) and gross energy (ADCE) while apparent protein digestibility (ADCP) was significantly decreased by the replacement of MBM or PBM (P < 0.05). The results suggest that MBM and PBM could replace up to 500 g kg?1 of fish meal protein in diets for gibel carp without negative effects on growth while 150 g kg?1 replacement by MBM protein improved feed utilization.  相似文献   

19.
Fishmeal (FM) is increasingly being replaced by plant proteins which are a relatively poor phosphorous source for mineralized tissues. To promote P availability plant‐based feedstuffs are supplemented with exogenous phytase. However, the effect of phytase on skeletal development in juvenile rainbow trout (Oncorhynchus mykiss) which have distinct mineral requirements is poorly understood. To address this juvenile trout were fed FM diet, a replacement feed (soybean meal, SBM) in which 50% (460 g kg?1) of crude protein (from FM) was substituted with soybean‐meal or SBM supplemented with microbial or corn‐expressed phytase. Vertebral and scale morphology, remodelling and mineralization were then assessed by histomorphometric and colorimetric assays. Body weight and SGR of trout fed SBM was lower than FM fed fish with no improvement noted with any phytase supplement. Vertebral mineral content and autocentrum morphology were similar in trout fed SBM or FM and supplementation with microbial‐phytase did not enhance these parameters at any concentration. However, scale and vertebral mineral content were significantly enhanced in trout fed SBM supplemented with corn‐expressed phytase 1500 FTU kg?1 (vertebral phosphorus P = 0.014, Ca P = 0.026; scale phosphorus P = 0.012). Thus, SBM feeds supplemented with corn‐expressed phytase could help reduce FM usage and generate a more robust skeleton less prone to deformity.  相似文献   

20.
This experiment was conducted to study whether practical fish meal based feeds for Atlantic salmon, Salmo salar L., require manganese (Mn) supplementation. Three thousand parr of initial weight 4.7 g were randomly distributed into 10 tanks and given a fish meal based diet, either unsupplemented or supplemented with 5, 10, 50 or 100 mg Mn kg?1 (as MnSO4*H2O) for 12 weeks. The basal diet contained 4.8 mg Mn kg?1. Mn concentration in vertebrae and whole fish responded linearly to supplemented Mn up to a level of 10 mg kg?1 and then reached a plateau. Dietary Mn supplementation did not affect weight gain, liver Mn concentration, blood haemoglobin concentration or haematocrit. To the practical feed, a supplementary level of 10 mg Mn kg?1, giving a total Mn concentration of 15 mg kg?1 diet, was necessary to maintain normal Mn status as determined by Mn level in vertebrae and whole fish. However, taking into account the variable Mn content in fish meal and the uncertainty about availability, we recommend a general supplementation of 15 mg Mn kg?1.  相似文献   

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