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1.
A feeding trial was conducted for 8 weeks to evaluate the effects of graded levels of neutral phytase supplementation using pretreatment or spraying method on growth performance, body composition, bone mineral content and serum biochemical parameter in grass carp, Ctenopharyngodon idellus. A control diet without phytase was added and six additional diets were arranged as a 2 × 3 factorial with two methods (pretreatment or spraying) and three levels of phytase (500, 1000 or 1500 U kg?1). The results showed that supplemental phytase at different levels in the diet and with different application methods all improved weight gain, specific growth rate and protein efficiency ratio of grass carp (P < 0.05). The feed conversion ratio in phytase‐supplemented groups was lower than the control. Dietary phytase addition reduced the lipid content in the whole body of grass carp. Phytase supplementation with different method increased ash and mineral (P, Ca, Mg and Zn) contents in whole‐body and vertebra (P < 0.05). The increase in these mineral contents was also observed in the serum. Based on the results, we may conclude that: 1) supplemental dietary phytase, regardless of the application methodology, improved the growth performance and nutrient utilization in grass carp; 2) the pretreatment mode of phytase application was more effective than spraying at the same phytase level.  相似文献   

2.
This study was designed to evaluate the effects of using soybean meal supplemented with or without methionine (M) and graded levels of phytase (P) to replace high‐level (60%) fish meal in the diets for juvenile Chinese sucker. Seven experimental diets (about 430 g kg?1 crude protein on dry matter basis) were formulated from practical ingredients. The control diet (FM) was formulated to contain 400 g kg?1 white fish meal (FM), whereas in the other six diets (diets 2–7), soybean meal (SBM) was used to replace 60% fish meal with or without methionine (3 g kg ?1) and 0,500, 1000, 1500 and 2000 U kg?1 phytase (designated as SBM, SM, SMP500, SMP1000, SMP1500 and SMP2000, respectively). Results from the feeding trial indicated that SBM without any methionine or phytase supplement replacing about 60% FM significantly affected the growth of fish (P < 0.05). Weight gain of fish fed diet SM was significantly higher than the fish fed diet SBM, but still much lower than fish fed the control diet (P < 0.05). SBM with methionine and phytase supplement significantly improved the growth of fish and apparent digestibility coefficients of phosphorus compared with the groups which fed diet SBM and diet SM (P < 0.05). Weight gain of fish fed SMP1000, SMP1500 and SMP2000 had no significant difference than fish fed control diet. Furthermore, fish fed SMP1500 showed optimum weight gain and ADC of phosphorus between these three groups. This suggested that soybean meal with 3 g kg?1 methionine and 1500 U kg?1 phytase supplement could successfully replace 60% fish meal in the diet for juvenile Chinese sucker without affecting growth and enhanced the apparent digestibility coefficient of phosphorus.  相似文献   

3.
A feeding trial was conducted to study the effect of partial replacement of dietary monocalcium phosphate (MCP) with neutral phytase on growth performance and phosphorus digestibility in gibel carp, Carassius auratus gibelio (Bloch). Control diet was prepared with 2% MCP but without phytase (P0). Other three experimental diets were prepared by replacement of MCP by 25%, 50% and 75% respectively in comparison with control with supplementation of neutral phytase at 500 U kg?1 diet in each and designated as P25, P50 and P75 respectively. Gibel carp (initial body weight of 30.22 ± 1.98 g) were reared in twelve 300‐L cylindrical fibreglass tanks provided with filtered flow‐through tap water at 26–28°C. After 8‐week experiment, gibel carp fed with P50 had no obvious differences from the control group on weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency rate (PER) and survival rate. Phytase supplementation did not affect body compositions or muscle compositions. Crude protein and phosphorus (P) contents in the faeces of fish fed with the phytase‐supplemented diets were significantly lower than those of the control group. The apparent digestibility coefficients (ADCs) of crude protein and P in gibel carp were increased when fish fed with the diets in which MCP was replaced by neutral phytase. This study suggested that partial replacement of dietary MCP at 50% with neutral phytase was considered as a recommended dietary supplemental level and increased dietary P and protein availability.  相似文献   

4.
Six isonitrogenous (320 g kg?1) and isolipidic (60 g kg?1) diets were formulated with graded levels (0, 5, 10 and 15 g kg?1) of dicalcium phosphate (DCP) and fungal phytase (750 and 1500 FTU kg?1 diet). Tra catfish (Pangasianodon hypophthalmus), 9.6 g, were fed the diets for 12 weeks. Each experimental diet was fed to eight replicates of fish to apparent satiation. At the end of the trial, fish fed the diets containing 15 g kg?1 DCP, 750 and 1500 FTU kg?1 phytase had higher growth performances, protein efficiency ratio and phosphorus retention than those fed the control diet, 5 g kg?1 DCP and 10 g kg?1 DCP diets (P < 0.05). Whole body ash and phosphorus concentration of fish fed the 10 g kg?1 DCP and 15 g kg?1 DCP diets were significantly higher than those of fish fed the control diet. Higher apparent digestibility coefficient of phosphorus was observed in fish fed the phytase supplemented diets. The present results indicate that supplementation of phytase at 750 FTU kg?1 and 1500 FTU kg?1 improves growth performances, feed and phosphorus utilization. The supplementation can completely replace dicalcium phosphate or other phosphorus sources in tra catfish feed and reduce the phosphorus discharge into environment.  相似文献   

5.
Two digestibility trials and two growth trials were carried out to evaluate the influence of top‐sprayed phytase on apparent digestibility coefficients (ADCs) of protein and mineral and utilization in rainbow trout fed with soybean meal‐based diets. In Trial 1, a semi‐purified diet containing 50% soybean meal was supplemented with graded levels of phytase (0, 500, 1000, 2000 and 4000 U kg?1 diet), and fed to triplicate groups of fish. In Trial 2, commercial‐type extruded feeds containing 36% soybean meal with either 0 or 2000 U phytase kg?1 were fed to five replicate groups of fish. Phytase clearly decreased phytic acid content of feces from 35 to 5 mg and from 34 to 14 mg phytic acid per g faecal dry matter in Trials 1 and 2 respectively. Apparent digestibility coefficient of P improved from 23% to 83% in Trial 1 and from 35% to 54% in Trial 2 by phytase. Apparent protein increased by 1.2% and 3.2%‐units by phytase in Trials 1 and 2. Zinc digestibility was significantly increased in Trial 1, but not in Trial 2. Trials 3 and 4 were conducted to evaluate the influence of phytase on dietary P (Trial 3) and lysine (Trial 4) utilization. Three diets were prepared for each trial: P (Trial 3)‐ or lysine (Trial 4)‐deficient basal diets, basal diets with phytase supplementation (2000 U kg?1) and P (Trial 3)‐ or lysine (Trial 4)‐fortified diets. Rainbow trout (initial weight 20 g) were fed for 10 weeks using four and six replicates for Trials 3 and 4 respectively. Phytase increased P utilization in Trial 3 as demonstrated by an increase in vertebra ash from 24.1% to 45.4%, and by an increase in weight gain from 243% to 459% of the initial weight. Phytase did not increase lysine utilization, since neither protein retention nor weight gain were enhanced by phytase. Supplemental lysine increased protein retention and weight gain to 43.1% and 514%, respectively, and also decreased whole‐body lipid contents significantly from 120 to 123 g kg?1 in fish fed the basal diet and phytase‐supplemented diet to 106 g kg?1 in fish fed with lysine‐fortified diet.  相似文献   

6.
This study was to assess effects of the pretreatment in all‐plant based diets with microbial phytase on phosphorous utilization and growth performance of Nile tilapia (Oreochromis niloticus). Pretreatment trials were conducted using phytase at graded doses to determine the optimal dose of phytase. Available phosphorus (P) levels increased significantly with the increased doses of phytase and the dose of 1000 U kg?1 was most efficient. Based on the pretreatment trials, plant based diets for Nile tilapia were formulated by pretreating with phytase at 1000 U kg?1. Experimental diets were supplemented with graded levels of mono calcium phosphate (MCP) at 25, 18.75, 12.5, 6.25 and 0 g kg ?1 diet. In addition, there were three controls: one phytase control, one inorganic P control and one pretreatment control. The results showed that diets pretreated with phytase gave better growth performance, feed conversion ratio and protein efficiency ratio of Nile tilapia compared with the phytase control diet and pretreatment control diet (P < 0.05). There were no significant differences in growth performance of Nile tilapia between the inorganic control diet and phytase pretreated diets supplemented with MCP at 25, 18.75 and 12.5 g kg?1 (P > 0.05), which resulted in significantly better performance than those at 6.25 and 0 g kg?1 (P < 0.05). Dietary interaction effects of phytase were observed for phosphorus retention efficiency and phosphorus load. Apparent digestibility coefficient of P (ADCp) was improved significantly by phytase pretreatment (P < 0.05). No significant difference was detected on ADC of crude protein among all experimental diets (P > 0.05).  相似文献   

7.
An 8‐week feeding trial was conducted in flow through system to examine the effects of dietary supplementation of microbial phytase on growth, nutrient utilization, haemato‐biochemical status and body compositions in common carp, Cyprinus carpio (L.) fingerlings (average weight 6.66 ± 0.08 g). The aim of experiment was also to determine whether dicalcium phosphates (DCP), tracemineral premix and lysine and methionine supplemental levels in carp diet could be reduced if microbial phytase was supplemented. Control diet (diet 1) supplemented with DCP, tracemineral premix and lysine and methionine without microbial phytase supplementation. Four experimental diets were formulated with reduction of either dietary DCP or trace minerals or lysine and methionine or all four supplementation levels by 100% of control diet without microbial phytase supplementation (diet 2, 3, 4 and 5 respectively). Another two experimental diets were formulated with reduction of all dietary DCP, trace minerals, lysine and methionine supplementation levels by 0 and 100% of control diet with dietary microbial phytase supplementation at 500 FTU kg−1 diet (diet 6 and 7 respectively). After acclimation of fish for 2 weeks, 20 fish were randomly stocked into triplicate tanks for each of seven treatments (T0, T1, T2, T3, T4, T5 and T6 for diet 1, 2, 3, 4, 5, 6 and 7 respectively) and fed with respective diet to apparent satiation. Results indicated that phytase was effective in releasing most of the phytate bound proteins, amino acids and minerals for optimum utilization and performance. Results also suggested that DCP, trace minerals and lysine and methionine supplementation level could be replaced by microbial phytase supplementation at 500 FTU kg−1 in soybean‐based common carp diets without altering the optimum performance of fish. Optimum replacement level of dietary DCP, trace minerals and lysine and methionine with phytase supplementation at 500 FTU kg−1 soybean‐based carp diet needs to be standardized in further investigations.  相似文献   

8.
A growth trial and a digestibility trial were conducted to evaluate the efficacy of phytase supplemented to practical shrimp feeds. The 5 weeks growth trial evaluated the effects of phytase supplementation in replete phosphorus (P) diets on the performances and compositions of juvenile Pacific white shrimp, Litopenaeus vannamei. No significant differences were observed in final biomass, final mean weight, weight gain, feed conversion ratio (FCR), protein retention and survival across all the treatments. Shrimp reared on the P deficient diet had significantly higher P retention and lower whole body P levels as compared to shrimp fed the other diets. Copper content in the whole shrimp body was significantly increased in the treatment supplemented with 1,000 IU kg?1 feed phytase. The digestibility trial was conducted to study the combined effects of phytase supplementation levels and diet type (plant‐based versus fishmeal‐based) on apparent digestibility coefficients of Pacific white shrimp, Litopenaeus vannamei. There were no effects of diet type so the data was combined. Phytase incorporation at both 500 and 2,000 IU kg?1 significantly improved protein digestibility, whereas P digestibility was enhanced when 2,000 IU kg?1 phytase was supplemented to the diet. Apparent digestibility coefficients of alanine, arginine, aspartic acid, cysteine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, serine, threonine, tyrosine and valine were significantly increased when fed diets contained 500 and 2,000 IU kg?1 phytase supplementation. Results of this work demonstrate that under the conditions of the study growth was not enhanced by phytase supplementation in P replete diets. However, nutrient retention for Cu and digestibility of P, protein and a number of amino acids were enhanced.  相似文献   

9.
A total of 900 juvenile Jian carp (Cyprinus carpio var. Jian) (7.99 ± 0.02 g) were fed diets containing graded levels of xylanase at 220 (unsupplemented control), 650, 1070, 1480, 1810 and 2470 U kg?1 diet for 10 weeks to investigate the effects of xylanase levels on growth performance, intestinal enzyme activities and microflora. The per cent weight gain, feed efficiency, protein efficiency ratio, protein production value, lipid production value, ash production value, calcium production value and phosphorus retention ratio were significantly improved with increasing levels of xylanase up to a point, and thereafter declined (P < 0.05). The activities of trypsin, chymotrypsin, lipase and amylase in the hepatopancreas and intestine, activities of alkaline phosphatase, Na+, K+‐ATPase, creatine kinase and γ‐glutamyl transpeptidase in three intestinal segments were improved by dietary xylanase (P < 0.05). The amounts of Lactobacillus, Escherichia coli and Aeromonas were significantly affected by dietary xylanase levels (P < 0.05). In conclusion, xylanase supplementation improved growth performance, enhanced intestinal enzyme activities and influenced the balance of intestinal microflora of juvenile Jian carp. The optimal level of xylanase in juvenile Jian carp (7.99–99.16 g) based on PWG was 1259 U kg?1 diet by the quadratic regression analysis.  相似文献   

10.
A feeding trial was conducted for 60 days to study the effects of exogenous microbial phytase supplementation on the growth and nutrient digestibility of Pangasius pangasius fingerlings. Eight isocaloric and isoprotein experimental diets (35.67% crude protein and 3870 kcal kg?1) were prepared with graded levels of phytase, e.g., 0 (T1), 150 (T2), 250 (T3), 350 (T4), 500 (T5), 1000 (T6) and 2000 (T7) FTU (phytase units) kg?1. Three hundred and fifteen fingerlings of P. pangasius (1.97–2.05 g) were randomly distributed in seven treatments with three replicates each. Maximum weight gain (350.72%), specific growth rate (2.51%), protein efficiency ratio (2.1), apparent net protein utilization (27.85%), energy retention value (88.47%) and feed conversion efficiency were observed in T5 group supplemented with 500 FTU phytase kg?1 diet. Apparent dry matter and protein digestibility in phytase‐supplemented groups were significantly (P<0.01) higher at a minimum supplement of 500 FTU kg?1 or higher. Liver alkaline phosphatase activity increased significantly in treatment groups. Supplementation at 500 FTU kg?1 of phytase is optimum in the diet of P. pangasius fingerlings.  相似文献   

11.
A ten‐week feeding trail was conducted to investigate the effects of increasing DL‐methionine (Met) supplementation on the success of fish meal (FM) replacement with plant proteins in practical diets for juvenile gibel carp, Carassius auratus gibelio. Twelve isoenergetic diets were formulated including two 150 g kg?1 FM diets (Diet 1—positive control 1 reflecting a commercial diet and Diet 2—positive control 2 reflecting a commercial diet but with balanced essential amino acid (EAA) profile) and ten 50 g kg?1 FM diets (negative controls) supplemented with graded levels (0–3.0 g kg?1) of DL‐Met (Diets 3–12). Each diet was fed to triplicate groups of gibel carp, near satiation four times daily for 10 weeks. Diet 2 with balanced EAA profile produced better final weight, specific growth rate (SGR) and feed conversion ratio (FCR) than the negative control diet containing no supplemental Met (Diet 3), but did not significantly differ from Diet 1. However, DL‐Met supplementation (0.5–3.0 g kg?1) in the negative control diets (Diets 4–12) produced growth performances similar to those fed the positive control diets (Diets 1 and 2). Based on quadratic regression analysis, the optimal dietary Met level with 5.2 g kg?1 of dietary cysteine (Cys) was found to be 7.1 g kg?1 dry diet for SGR and FCR. The corresponding total sulphur amino acid requirements (Met + Cys) of this species were calculated to be 12.3 g kg?1 dry diet for SGR and FCR. DL‐Met supplementation in 50 g kg?1 FM diets showed a decreasing trend in plasma cholesterol contents (p < .05). No significant differences were observed in whole‐body composition, plasma protein, triglyceride and free EAA contents among dietary treatments, while plasma aspartate transaminase, albumin and ammonia contents were significantly influenced by dietary Met levels. Juvenile gibel carp grew equally well on 150 g kg?1 FM diet or 50 g kg?1 FM diets balanced for EAA profile with supplemental amino acids. The results of this study overall indicate that balancing dietary amino acid levels with DL‐Met supplementation is a key strategy in successfully reducing FM levels in the diets of gibel carp.  相似文献   

12.
An 11‐week growth trial was conducted to determine dietary myo‐inositol (MI) requirement for juvenile gibel carp (Carassius auratus gibelio). Myo‐inositol was supplemented to the basal diet to formulate six purified diets containing 1, 56, 107, 146, 194 and 247 mg MI kg?1 diet, respectively. Each diet was fed to triplicate groups of juvenile gibel carp (initial body weight 3.38 ± 0.27 g, mean ± SD) in a flow‐through system. The diets were randomly assigned to different fish tanks. Fish fed ≥ 107 mg MI kg?1 diet had significantly higher weight gain (WG), feed efficiency (FE) and protein efficiency ratio than those fed 1 mg MI kg?1 diet. Fish fed ≥ 56 mg MI kg?1 diet had higher feeding rate and survival compared with fish fed 1 mg MI kg?1 diet. Dietary supplemental inositol did not affect fish liver inositol concentration. Fish fed ≥ 56 mg MI kg?1 diet had higher body dry matter, crude protein and gross energy and lower hepatosomatic index than fish fed 1 mg MI kg?1 diet. Dietary inositol supplementation decreased fish body ash. Quadratic regression of weight gain indicated that the myo‐inositol requirement to maximum growth for juvenile gibel carp was 165.3 mg MI kg?1 diet.  相似文献   

13.
A 76‐day feeding trial was carried out to evaluate the effects of Lysine and Methionine supplementation on growth and digestive capacity of grass carp (Ctenopharyngodon idella) fed plant protein diets using high‐level canola meal (CM). Fish with initial average weight 103.9 ± 0.6 g were fed three extruded diets. Fish meal (FM) diet was formulated as the normal control with 40 g kg?1 FM and 300 g kg?1 CM; CM diet was prepared by replacing all FM with CM (total 340 g kg?1) without Lys or Met supplementation; CM supplement (CMS) diet was similar to CM diet but was supplemented with essential amino acids (EAA) to ensure the levels of Lys and Met similar to those in the FM diet. Feed intake, feed efficiency and specific growth rate of the grass carp fed CMS and FM diets were similar (P > 0.05), but higher than those of the grass carp fed CM diet (P < 0.05). The hepatosomatic index, relative gut length, intestosomatic index and intestinal folds height were significantly improved in fish fed FM and CMS diets as compared to CM diet (P < 0.05). Lower activities of trypsin, lipase and amylase in hepatopancreas were observed in fish fed CM diet (P < 0.05). Three hundred and forty gram per kilogram CM without Lys or Met supplementation significantly decreased trypsin, lipase and amylase mRNA levels in hepatopancreas (P < 0.05). These results indicated that the high supply of CM (340 g kg?1) in plant protein (200 g kg?1 soybean meal and 100 g kg?1 cottonseed meal) diets decreased digestive ability through decreasing digestive enzyme activities and enzyme gene's expressions of grass carp, and these side effects can be reversed by supplementing Lys and Met. Therefore, CM could be high level used in a plant protein blend‐based extruded diet for grass carp as long as EAA were supplemented.  相似文献   

14.
Two 8‐wk studies were conducted to evaluate the effects of neutral phytase supplementation on hemato‐biochemical status, liver biochemical parameter, and intestinal digestive enzyme activity of grass carp, Ctenopharyngodon idellus, and gibel carp, Carassius auratus gibelio, fed with different levels of monocalcium phosphate (MCP). The control diet was prepared with 2% MCP but without phytase (P2.0). The other three experimental diets were prepared with the addition of 1.5, 1.0, and 0.5% MCP, respectively, when supplemented with 500 U/kg neutral phytase in each diet and designated as PP1.5, PP1.0, and PP0.5, respectively. The results indicated that the serum alkaline phosphatase (ALP), alanine transaminase (ALT), and aspartate transaminase (AST) activities, as well as the albumin (ALB) content were increased in grass carp (P < 0.05) and gibel carp (P > 0.05) fed with phytase‐supplemented diets. Meanwhile, the serum cholesterol, high‐density lipoprotein, and total protein contents of the two species of fish were increased in comparison to the control. In addition, dietary phytase inclusion did not significantly affect hepatic ALP, ALT, and AST activities in the two species of carp fed with different levels of MCP. Amylase activity increased in foregut and hindgut of both species when fed with the phytase‐supplemented diets while lipase activity was reduced in the foregut and hindgut in both fish. This study suggests that neutral phytase supplementation increases serum ALP, ALT, and AST activities but does not notably affect these enzyme activities in the liver of the two species of carp when fed different levels of MCP. On the other hand, amylase activity increased while lipase activity was reduced in the intestine of the species of carp fed with phytase‐supplemented diets.  相似文献   

15.
A 75 days experiment was conducted in a flow‐through system on juvenile gibel carp (Carassius auratus gibelio) (3.43 ± 0.01 g) to evaluate the effects of dietary lysozyme on growth performance, intestine morphology, microbiota and immune response. Four isonitrogenous (crude protein: 367 g kg?1) isolipid (62 g kg?1) and isocaloric (gross energy: 17.92 kJ g?1) diets were formulated to contain 0, 100, 500 and 1000 mg kg?1 lysozyme, respectively. The results showed that specific growth rate (SGR) and feed efficiency (FE) increased at 1000 mg kg?1 lysozyme. Blood leucocyte phagocytic activity (PA) and serum lysozyme (LZM) decreased with dietary lysozyme on day 25, 50 and 75. There were no significant differences in alternative complement pathway (ACP), respiratory burst (ROS), serum superoxide dismutase (SOD), glutathione peroxidase (GSHpx) or malonaldehyde (MDA). After Aeromonas hydrophilia challenge, higher survival was obtained at 500 mg kg?1 group. PA, ROS, SOD, LZM and ACP increased with increasing dietary lysozyme, while MDA reversed. Goblet cells in mid‐intestine and microvilli height in distal intestine increased with dietary lysozyme on day 75. Dietary lysozyme reduced the diversity of intestine microbiota. In conclusion, oral administration of 500 mg kg?1 dietary lysozyme for 75 days is recommended for the survival of gibel carp and 1000 mg kg?1 dietary lysozyme for fast growth.  相似文献   

16.
A 63‐day growth trial was undertaken to estimate the effects of supplemented lysine and methionine with different dietary protein levels on growth performance and feed utilization in Grass Carp (Ctenopharyngodon idella). Six plant‐based practical diets were prepared, and 32CP, 30CP and 28CP diets were formulated to contain 320 g kg?1, 300 g kg?1 and 280 g kg?1 crude protein without lysine and methionine supplementation. In the supplementary group, lysine and methionine were added to formulate 32AA, 30AA and 28AA diets with 320 g kg?1, 300 g kg?1 and 280 g kg?1 dietary crude protein, respectively, according to the whole body amino acid composition of Grass Carp. In the groups without lysine and methionine supplementation, weight gain (WG, %) and specific growth rate (SGR, % day?1) of the fish fed 32CP diet were significantly higher than that of fish fed 30CP and 28CP diets, but no significant differences were found between 30CP‐ and 28CP‐diet treatments. WG and SGR of the fish fed 32AA and 30AA diets were significantly higher than that of fish fed 28AA diets, and the performance of grass carp was also significantly improved when fed diets with lysine and methionine supplementation (P < 0.05), and the interaction between dietary protein level and amino acid supplementation was noted between WG and SGR (P < 0.05). Feed intake (FI) was significantly increased with the increase in dietary protein level and the supplementation of lysine and methionine (P < 0.05), but feed conversion ratio (FCR) showed a significant decreasing trend (P < 0.05). Two days after total ammonia nitrogen (TAN) concentration test, the values of TAN discharged by the fish 8 h after feeding were 207.1, 187.5, 170.6, 157.3, 141.3 and 128.9 mg kg?1 body weight for fish fed 32CP, 32AA, 30CP, 30AA, 28CP and 28AA diets, respectively. TAN excretion by grass carp was reduced in plant‐based practical diets with the increase in dietary protein level and the supplementation of lysine and methionine (P < 0.05). The results indicated that lysine and methionine supplementation to the plant protein sources‐based practical diets can improve growth performance and feed utilization of grass carp, and the dietary crude protein can be reduced from 320 g kg?1 to 300 g kg?1 through balancing amino acids profile. The positive effect was not observed at 280 g kg?1 crude protein level.  相似文献   

17.
An experiment was conducted to determine the effects of different levels of dietary vitamin C (VC) and E (VE) supplementation on fillet quality of red sea bream fed oxidized fish oil (OFO). Fish with an average body weight of 205.0 g were fed four test diets for 9 weeks. Control diet contained fresh fish oil (FFO) with 100 mg kg?1 of VE and 500 mg kg?1 of VC (FFO100E/500C). The other three diets contained OFO with varying levels of VE (mg kg?1) and VC (mg kg?1) (OFO100E/500C, OFO200E/500C and OFO200E/1000C). After feeding trial, two fillets from each fish by hand filleting were stored in a refrigerator at 4°C for 96 h during analyses. Results showed that fish fed OFO increased fillet thiobarbituric acid reactive substances (TBARS) and K‐value, and decreased fillet VC and VE concentrations during storage time. Supplementation of VC did not have any detectable effect on fillet quality. Increasing dietary VE supplementation increased fillet VE concentrations, reduced fillet TBARS and K‐value values of red sea bream. Therefore, we suggest that dietary supplementation of 200 mg kg?1 of vitamin E could improve fillet oxidative stability of red sea bream fed OFO.  相似文献   

18.
A 49‐days feeding trial was conducted to study the effects of sodium butyrate on growth performance, gut morphology of juvenile grass carp. Five isoenergetic and isonitrogenous experimental diets were compounded by the supplementation in the basal diet with gradient sodium butyrate at 0, 500, 1000, 2000, 3000 mg kg?1 respectively. A total of 375 juvenile grass carp (with initial body weight of 3.8 g) were randomly allocated into five diet treatments, and each treatment has three replicates. The results showed that the specific growth rate (SGR) of SB1000 and SB2000 group was significantly higher (P < 0.05) than that of the other groups. Moreover, the lowest SGR was observed in SB3000 group. Feeding rate and the whole‐body proximate composition including moisture, crude lipid, crude protein and crude ash were not affected by sodium butyrate (P > 0.05). Total superoxide dismutase activities in hepatopancreas in the experimental groups were significantly higher than those in the control group (P < 0.05). Glutathione peroxidase activity in hepatopancreas was significantly upregulated by dietary sodium butyrate level (P < 0.05). However, the activity of total antioxidant capacity and the contents of malondialdehyde were not significantly different among groups. The expression levels of mRNA encoding PepT1 and LAT2 in the foregut both showed a first increasing and then decreasing tendency as dietary sodium butyrate level increased (P < 0.05), and peaked in SB1000 and SB2000 groups respectively. The results indicated that appropriate dietary supplementation of sodium butyrate at 2000 mg kg?1 could improve the growth, antioxidant ability and intestinal absorption capacity of the juvenile grass carp.  相似文献   

19.
A 60‐day feeding trial was conducted to quantify the effects of microbial phytase supplementation on apparent absorption, whole body and bone contents of minerals in Pangasius pangasius fingerlings. Seven isoprotein (35.67%) and isocaloric (3870 kcal kg?1) diets were prepared with graded levels of supplemental phytase at 0 (T1), 150 (T2), 250 (T3), 350 (T4), 500 (T5), 1000 (T6) and 2000 (T7) FTU (Phytase Units) kg?1. Three hundred and fifteen fingerlings of P. pangasius (1.97–2.05 g) were randomly distributed in seven treatments with three replicates each. There was significant increase (P<0.05) in tissue protein content in phytase‐supplemented groups compared with the control. Apparent absorptions of calcium (Ca), phosphorus (P), magnesium (Mg), manganese (Mn), zinc (Zn), iron (Fe), potassium (K), copper (Cu) and cobalt (Co) were significantly (P<0.05) higher in the phytase‐supplemented groups than the control group. Faecal ash and P contents were significantly (P<0.05) higher in the control (T1) than the phytase‐supplemented groups. Whole‐body contents of Ca, P, Zn, Fe, Cu and Co were significantly (P<0.05) improved by the dietary supplementation of phytase‐barring Mg and Mn. Concentrations of bone Ca, P, K, Cu and Co were significantly (P<0.05) higher in phytase‐supplemented groups. Bone ash contents (40.77–44.85%) were increased concomitantly with the increased level of phytase inclusion upto 500 FTU kg?1 diet. It was observed that a minimum dose of 250 FTU phytase kg?1 diet improved the mineral absorption and utilization in P. pangasius fingerlings.  相似文献   

20.
The effect of the different dietary carbohydrate types and levels on growth performance, haematological indices and hepatic hexokinase (HK) and glucokinase (GK) genes expression involved in control of glucose metabolism, was studied in juvenile mirror carp (Cyprinus carpio). Two carbohydrates (glucose and starch) diets with two levels (250 and 500 g kg?1) were fed to triplicate groups of 35 fish for 60 days. The best weight gain rate and specific growth rate were observed in fish fed with 250 g kg?1 glucose diet and 500 g kg?1 starch diet (P < 0.05). Fish fed with 500 g kg?1 glucose showed low feed utilization, with the highest food conversion ratio and the lowest protein efficiency ratio (P < 0.05). Hepatosomatic index was significantly higher in fish fed with glucose diets and the 500 g kg?1 starch diet compared to 250 g kg?1 starch. CHOL, HDL‐C and LDL‐C were significantly highest in fish fed with 500 g kg?1 starch than all other diets (P < 0.05). Hepatic GK mRNA expression level and activity were positively related to glucose and starch levels (P < 0.05). Correlation analysis showed that hepatic glycogen concentration was increased by dietary carbohydrate content (P < 0.05). These results suggest that GK may play a major role in the postprandial glucose utilization in juvenile mirror carp.  相似文献   

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