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1.
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   

2.
Juvenile Litopenaeus vannamei farmed at 3.0 psu were fed five diets containing glucose, sucrose, wheat starch, corn starch or potato starch as the carbohydrate (CBH) source. Shrimp were fed for 50 days to explore the effect of dietary CBH source on growth, body composition and ammonia tolerance. The specific growth rate of body length of shrimp fed glucose was the highest and significantly higher than those fed potato starch. The survival rate of shrimp fed glucose was 89.44%, and it was the highest and significantly higher than those fed wheat starch. Whole shrimp body crude protein and lipid of the corn starch group were 140.2 g kg?1 and 10.1 g kg?1 respectively. And they were significantly higher than those fed wheat starch. Shrimp fed potato starch had higher hepatopancreas and muscle glycogen. Shrimp fed sucrose had higher glucose‐6‐phosphate dehydrogenase and lower pyruvate kinase activities (P < 0.05). Besides, shrimp fed starch produced more B cells in hepatopancreas tubules than those fed glucose or sucrose. Shrimp fed different sources of CBH differed in the number of R cells. After 96‐h of ammonia nitrogen challenge, the survival rate of the treatments from high to low in turn was glucose, wheat starch, corn starch, sucrose and potato starch, and no significant differences were observed among all treatments. Based on shrimp growth and the economic problems of practical production, we recommend wheat starch as CBH source in practical diets for L. vannamei farmed at low salinities.  相似文献   

3.
The effects of using increasing levels of carbohydrate to replace protein in diets for Atlantic salmon were studied in a long-term, semicommercial-scale experiment in sea cages, using wheat and corn starch as carbohydrate sources. The fish were fed extruded diets containing 24 g and 602 g kg?1, 98 g and 521 g kg?1, 165 g and 454 g kg?1, 230 g and 384 g kg?1 of carbohydrate and protein, respectively. The contents of lipid were kept constant at 280 g kg?1. The experiment lasted for 9 months until the fish had reached about 4 kg. All groups showed good growth in the experimental period. Feed efficiency decreased and feed intake increased linearly with increased level of carbohydrate in the diet. Digestibility of dry matter and energy were seriously decreased with increased carbohydrate level in the diets. This was mainly due to decreased digestibility of carbohydrate, but also to decreased digestibility of lipid. The digestibility of protein or amino acids was not affected by diet. Higher levels of carbohydrate resulted in increased storage of energy as lipid in fillet and abdominal fat. Red coloration showed an optimum at 98 g kg?1 carbohydrate in the diets. No differences in maturation were found between diets. Overall, based on feed efficiency, growth and slaughter quality, the optimum level of carbohydrate in the diet for Atlantic salmon in sea water is found to be approximately 100 g kg?1 dry matter.  相似文献   

4.
为了解罗非鱼对不同种类碳水化合物(CBH)的利用效果,研究了6种碳水化合物对罗非鱼生长性能、体组成和血清生化指标的影响。实验选用720尾初重为(3.0±0.3)g的健康吉富罗非鱼,随机分为6组,每组4个重复,每个重复30尾,分别投喂设计含30%南方糙米、次粉、玉米淀粉、马铃薯淀粉、甘薯淀粉和木薯淀粉的6种不同CBH的等氮、等能饲料,实验周期为8周。结果显示,南方糙米、玉米淀粉组的终末均重、增重率、特定生长率和蛋白效率显著高于其他组,而饲料系数明显最低(P0.05)。CBH种类明显影响全鱼、肌肉的组成(P0.05)。玉米淀粉组肝糖原含量明显高于马铃薯淀粉、甘薯淀粉和木薯淀粉组(P0.05),而马铃薯淀粉和甘薯淀粉组的血糖明显低于木薯淀粉、玉米淀粉和次粉组(P0.05)。CBH种类对血清CHO、TG影响明显(P0.05),但对TP、SOD、T-AOC和MDA的影响不明显(P0.05)。研究表明,不同种类CBH对罗非鱼生长性能的影响明显(P0.05),以特定生长率为指标,罗非鱼对南方糙米和玉米淀粉的利用效果较好。  相似文献   

5.
Two feeding experiments were conducted to evaluate dietary distillers dried grain (DDG) as a feed ingredient that partially replaces soybean meal and wheat flour for the growth of juvenile freshwater snail (Semisulcospira coreana) and abalone (Haliotis discus hannai). Three experimental diets were formulated to contain 0 g kg?1 DDG (DDG0), 200 g kg?1 DDG from rice (diet DDG‐R) and 200 g kg?1 DDG from rice and wheat flour (diet DDG‐RW). In the first experiment, three replicate groups of the freshwater snails averaging 133.0 ± 2.48 mg were fed one of the experimental diets for 12 weeks. Weight gain of the juvenile freshwater snails was not affected by dietary DDG (P > 0.05). In the second experiment, three replicate groups of the juvenile abalones averaging 296.3 ± 1.73 mg were fed one of the three experimental diets for 22 weeks. Weight gain of the abalones was not affected by dietary DDG (P > 0.05). Proximate and amino acid compositions of the whole body in the freshwater snails and soft body in the abalones were not affected by dietary DDG (P > 0.05). The results of the two experiments indicated that DDG can be used as a suitable feed ingredient for partial replacement of soybean meal and wheat flour at a level of 200 g kg?1 in diets without any adverse effects on the growth performance of freshwater snail and juvenile abalone.  相似文献   

6.
Sablefish Anoplopoma fimbria is a piscivorous fish that is highly desirable as food. To ascertain the relationship of dietary protein, lipid and carbohydrate, eleven diets containing fishmeal, fish oil and wheat flour as test ingredients at different levels were formulated. The levels were chosen according to mixture experiment methodology, which varies the proportion of each test ingredient, while keeping their sum constant across all diets. The range of levels used in the test diets were as follows: fishmeal 430–600 g kg?1, fish oil 100–270 g kg?1 and wheat flour 30–200 g kg?1. The sum of the test ingredients accounted for 900 g kg?1 of all diets, with the remaining 100 g kg?1 accounting for mineral and vitamin premix, binders, attractant, etc. Each diet, plus a commercial feed, was fed to three tanks of juvenile sablefish by hand twice daily for 11 weeks, using a completely random design. It was found that growth and feed efficiency were maximized by the highest dietary inclusion level of fish oil and fishmeal, corresponding to the lowest wheat flour level, that is 600 g kg?1 fishmeal, 270 g kg?1 fish oil and 30 g kg?1 wheat flour.  相似文献   

7.
Two 8‐week feeding trials were conducted to evaluate dietary carbohydrate utilization by omnivorous gibel carp (Carassius auratus gibelio) (2.4 ± 0.1 g) and herbivorous grass carp (Ctenopharyngodon idellus) (6.5 ± 0.1 g). Five isonitrogenous (370 g kg?1) and isolipid (70 g kg?1) diets were formulated with increasing corn starch levels (60, 140, 220, 300 and 380 g kg?1). Results showed that specific growth rate (SGR), feed efficiency (FE) and protein retention efficiency (PRE) of gibel carp significantly increased from dietary starch of 60 to 300 g kg?1 and then decreased from 300 to 380 g kg?1, but those of grass carp showed no significant differences between treatments. Independent of dietary starch levels, grass carp gained significantly higher FE and PRE than gibel carp. Feeding rate (FR) of gibel carp was significantly higher than that of grass carp. In two fish species, high dietary starch (300 and 380 g kg?1) tended to obtain higher hepatosomatic index (HSI), serum triglyceride, hepatic lipid and body lipid contents. Serum glucose concentration of grass carp was not affected, while that of gibel carp fed the starch of 300 g kg?1 diet was significantly lower than those of the fish fed other four diets (60, 140, 220 and 380 g kg?1). Grass carp showed high tolerance to dietary starch while dietary corn starch should be no more than 300 g kg?1 for gibel carp. High starch contents may cause lipid accumulation in the liver and body.  相似文献   

8.
The aim of the present work was to test the capacity of Octopus vulgaris to use carbohydrates supplied in three diets: a diet without added carbohydrates (diet C0: 500 g kg?1 water, 200 g kg?1 gelatine, 100 g kg?1 egg yolk powder, 50 g kg?1 freeze‐dried Sardinella aurita and 150 g kg?1 freeze‐dried Todarodes sagittatus) and two obtained by substituting 50 g kg?1 of T. sagittatus by glucose (diet GLU50) or by starch (diet STA50). The most stable and best‐accepted diet was STA50 (SFR 1.26%BW day?1) although there were no significant differences in the growth rates obtained with the three diets: 10.12 g day?1, 9.37 g day?1 and 11.22 g day?1 for C0, GLU50 and STA50, respectively (P > 0.05). The feed efficiency indices were better for GLU50, of particular note being the protein productive value of 71.88% and a feed conversion ratio lower than 1. Protein and lipid digestibility were similar in all the three diets (96–98% for proteins and 85–94% for lipids), whereas carbohydrate digestibility was higher in GLU50 (98%) than in C0 (84%) and STA50 (0.33%). The content of carbohydrates increased in muscle and the digestive gland as a consequence of the increased carbohydrates intake.  相似文献   

9.
Evaluation of vegetable oils and poultry fat digestibility is the first step to elicit their use in aquafeeds. This work aimed at determining apparent digestibility coefficients (ADCs) of energy, lipids and fatty acids of oil sources for pacu, a widely farmed neotropical Characin. A semipurified, omnivorous fish diet (344.2 g kg?1 crude protein; 18.16 MJ kg?1 gross energy) was used as reference diet. Test diets were obtained by adding 2 g kg?1 chromium III oxide and replacing 15 g kg?1 reference diet with fish, soybean, colza, corn and flaxseed oils and poultry fat. Juvenile pacu (64 ± 10.8 g; 14.6 ± 1.1 cm) were fed to apparent satiety, four times a day, and then transferred to cylindrical–conical aquaria for collection of faeces by sedimentation (n = 3). Apparent digestibility coefficients of energy and lipids were high for all tested oils (> 0.05); ADCs of saturated fatty acid (SFA) were lower than monounsaturated fatty acids (MUFA) and polyunsaturated fatty acid (PUFA). Essential fatty acids (18:2n‐6 and 18:3n‐3) had high ADC (>93%), colza oil and poultry fat yielding the lowest ADC for 18:2n‐6 (= 0.01) and 18:3n‐3 (< 0.01), respectively. Corn oil, soybean oil and flaxseed oil were interesting sources of 18:2n‐6 and 18:3n‐3 dietary fatty acids for pacu.  相似文献   

10.
The effects of exogenous digestive enzyme supplements on the digestibility of wheat starch or diets containing either wheat or dehulled lupin (Lupinus angustifolius var. gungurra) by silver perch (Bidyanus bidyanus) were investigated. In the first experiment, Natustarch® (α‐amylase supplement specific to starch) was added at three nominal concentrations (0, 50, 100 or 150 mg kg?1 diet) to diets containing either raw or 100% gelatinized wheat starch (30% dietary inclusion content) and fed to silver perch. The apparent digestibility coefficients (ADCs) for dry matter, starch and energy were calculated. The action of Natustarch® on the diet and in the digestive tract was also investigated. The addition of Natustarch® to diets containing raw and gelatinized wheat starch led to an average increase in reducing sugar content of diets of 67% and 340% respectively, indicating that the α‐amylase was more efficient at hydrolysing wheat starch in the gelatinized form. Gelatinized wheat starch was digested more efficiently than raw wheat starch. However, although the addition of Natustarch® at ≥ 50 mg kg?1 led to a significant increase in digestibility of raw wheat starch; the digestibility of gelatinized wheat starch, which was already high, was not further improved. Leaching due to immersion in water caused a minor loss of α‐amylase activity from diet pellets treated with Natustarch® (~ 13% after 5 min). The α‐amylase activity in the anterior section of the intestinal tract of silver perch fed diets containing Natustarch® was not affected, indicating that the α‐amylase had been denatured by the acidic conditions in the stomach of silver perch. In the second experiment, diets containing wheat or lupin (at the 30% inclusion content) were treated with Natugrain‐blend®[an enzyme supplement containing β‐glucanase and β‐xylanase, specific to non‐starch polysaccharides (NSPs)] at three nominal concentrations (0, 75, 150 or 300 μL kg?1) and fed to silver perch. ADCs for energy and protein were calculated. The addition of Natugrain‐blend® had no effect on dry matter, energy or protein digestibility of the diets or ingredients.  相似文献   

11.
The effect of six different binding agents (agar, sodium alginate, cassava starch, gelatin, wheat gluten and kelp meal) in two concentrations (30 g kg−1 and 50 g kg−1) were evaluated with respect to physical quality of Litopenaeus vannamei broodstock pelleted feed, after 15, 30, 60, 90, 120, 150 and 180 min of water immersion. The best treatments in terms of water stability, water absorption and protein leaching were obtained with sodium alginate and wheat gluten at 50 g kg−1. In a second experiment, the feed ingestion and diet digestibility with these two binders and their combination (1 : 1) were compared against a control diet containing 50 g kg−1 wheat flour. There were no significant differences (> 0.05) in the daily feed ingestion rate 2.39–3.33% of the biomass. The most representative values of apparent digestibility of protein (ADP) and apparent dry matter digestibility (ADMD) were achieved with diets containing wheat gluten and alginate + gluten mixture as binder. Based on these results, combinations with 50 g kg−1 wheat gluten is recommended as binder in pelleted feed for broodstock L. vannamei.  相似文献   

12.
The apparent digestibility of protein, fats, carbohydrate and energy within three feed ingredients (wheat, barley and corn) for common carp, Cyprinus carpio Linnaeus, was studied, using chromic oxide as a dietary marker. Each experimental diet consisted of a mixture of the test ingredient and 50% basal diet (containing 50% soybean meal, 35% wheat meal, 10% soybean oil, plus 5% vitamins, egg yolk, guar and chromic oxide). It was found that in wheat meal the protein had an apparent digestibility of 92%, and the lipid an apparent digestibility of 80%. The apparent digestibility of corn was 81% for protein and 90% for lipid, while for barley the figures were 73% and 67%, respectively. For apparent digestible energy, the figures were 12.39 kJ g?1 for wheat, 6.69 kJ g?1 for barley and 9.32 kJ g?1 for corn.  相似文献   

13.
This study was designed to evaluate the efficacy of eight sources (designated A–H) of soybean meal (SBM) which included six new non‐genetically modified soya varieties in practical feed formulation for Pacific white shrimp, Litopenaeus vannamei, using both growth and digestibility trials. A soybean meal‐based reference diet was formulated using conventional soybean meal (527 g kg?1 diet), which was then replaced on an isonitrogenous basis with various other experimental soybean meals. In a 6‐week growth trial, shrimp in four replicate tanks per dietary treatment (10 shrimp per tank, initial weight 0.52 ± 0.04 g) were cultured in a recirculating system. There were no significant differences with respects to per cent weight gain and survival across all dietary treatments; however, final weights and feed conversion ratio (FCR) were lower in shrimp offered diet 3. Apparent digestibility coefficients for the eight (A–H) different soybean meals were determined in L. vannamei for dry matter (ADMD), gross energy (ADE) and crude protein (ADP) using 10 g kg?1 chromic oxide as inert marker with 70 : 30 replacement techniques. Coefficients ranged from 71.3% to 88.3%, from 76.6% to 91.3% and from 93.6% to 99.8%, for ADMD, ADE and ADP, respectively. Improved digestibility values were observed in soybean C which was characterized by crude protein (471 g kg?1), crude fat (97 g kg?1), low cooking temperature (180 °C), higher nitrogen solubility index (689 g kg?1) and protein dispersibility index (619 g kg?1). This indicates that new lines of soybean meal can be used to improve digestibility coefficients in shrimp feeds.  相似文献   

14.
Knowledge on apparent digestibility coefficients (ADC) is necessary to maximize the feed efficiency, thus lessening dietary nutrient and energy losses. This study tasks the determination of apparent digestibility of selected feedstuff to striped surubim Pseudoplatystoma reticulatum, a carnivorous, South American catfish of economic importance for fisheries and fish culture alike. Juvenile striped surubim (82.4 ± 17.7 g and 23.0 ± 1.6 cm) was distributed in 21 cylindrical, plastic cages (80 L), housed in seven 1000 L feeding tanks under constant water flow and aeration and conditioned to a two daily meals (20h00m and 22h00m) feeding regimen on a practical, reference diet (RD) (460.0 g kg?1 crude protein (CP); 19.23 kJ g?1 gross energy (GE)]. Test diets were obtained by adding of 1 g kg?1 chromium III oxide and 300 g kg?1 of one the following feedstuffs: fish meal (FM), meat and bone meal (MBM), poultry by‐product meal, feather meal, blood meal, soybean meal, wheat bran, corn and corn gluten meal to the RD. After the last daily meal, fish were transferred to cylindrical, conical‐bottomed aquaria (200 L) under aeration and continuous water exchange, coupled to refrigerated plastic bottles for faeces collection by sedimentation. Best ADC of protein (99.36%) and energy (86.25%) were recorded for poultry by‐product meal and MBM, respectively, which are thus deemed ideal surrogate feedstuffs to FM in the formulation and processing of diets for striped surubim.  相似文献   

15.
Five diets were formulated to provide an isoproteic daily dietary intake of 15 g kg?1 day?1, while maintaining daily starch intake ranging from 0 to 40 g kg?1 day?1. The 4‐week experiments started with initial mean weights of 4.7 and 4.4 g for Pangasius bocourti and P. hypophthalmus, respectively. The results clearly show the protein sparing action of starch in both species. Best protein retention was obtained with starch intake of 20 and 10 g kg?1 day?1 for P. bocourti and P. hypophthalmus, respectively, which was equivalent to 40 and 20% starch in the feed. Pangasius bocourti and P. hypophthalmus fingerlings attained maximal growth with starch intake of 30 and 10 g kg?1 day?1, equivalent to 60 and 20% starch in the feed. It was noted that body lipid accumulation was much higher in P. bocourti than in P. hypophthalmus, and that excess dietary starch intake depressed diet digestibility and growth.  相似文献   

16.
The aim of the present work was to test the capacity of O. vulgaris to use carbohydrates supplied in three diets: a diet without added carbohydrates (diet C0: 500 g kg?1 water, 200 g kg?1 gelatine, 100 g kg?1 egg yolk powder, 50 g kg?1 freeze‐dried Sardinella aurita and 150 g kg?1 freeze‐dried Todarodes sagittatus), and two obtained by substituting 50 g kg?1 of T. sagittatus by glucose (diet GLU50) or by starch (diet STA50). The most stable and best accepted diet was STA50 (SFR 1.26%BW day?1), although there were no significant differences in the growth rates obtained with the three diets: 10.1 g day?1, 9.4 g day?1 and 11.2 g day?1 for C0, GLU50 and STA50, respectively (> 0.05). The feed efficiency indices were better for GLU50, of particular note being the protein productive value of 72% and a feed conversion ratio lower than 1. Protein and lipid digestibility were similar in all three diets (96–98% for proteins and 85–94% for lipids), whereas carbohydrate digestibility was higher in GLU50 (98%) than in C0 (84%) and STA50 (0.33%). The content of carbohydrates increased in muscle and the digestive gland as a consequence of the increased carbohydrates intake.  相似文献   

17.
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 (< 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 (< 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 (< 0.05). Hepatic GK mRNA expression level and activity were positively related to glucose and starch levels (< 0.05). Correlation analysis showed that hepatic glycogen concentration was increased by dietary carbohydrate content (< 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   

18.
The nutritional function of monosaccharides, disaccharides and polysaccharides for omnivorous gibel carp and carnivorous Chinese longsnout catfish were investigated and the ability of these two species to utilize carbohydrates was compared. For each species, triplicate groups of fish were assigned to each of five groups of isoenergetic and isonitrogenous experimental diets with different carbohydrate sources: glucose, sucrose, dextrin, soluble starch (acid‐modified starch) and α‐cellulose. The carbohydrates were included at 60 g kg?1 in Chinese longsnout catfish diets and at 200 g kg?1 in gibel carp diets. A growth trial was carried out in a recirculation system at 27.8 ± 1.9 °C for 8 weeks. The results showed that fish with different food habits showed difference in the utilization of carbohydrate sources. For gibel carp, better specific growth rate (SGR) and feed efficiency (FE) were observed in fish fed diets containing soluble starch and cellulose, but for Chinese longsnout catfish, better SGR and FE were observed in fish fed diets containing dextrin and sucrose. Apparent digestibility coefficient of dry matter (ADCd) and apparent digestibility coefficient of energy (ADCe) were significantly affected by dietary carbohydrate sources in gibel carp. ADCd and ADCe significantly decreased as dietary carbohydrate complexity increased in Chinese longsnout catfish except that glucose diet had medium ADCd and ADCe. In both species, no significant difference of apparent digestibility coefficient of protein was observed between different carbohydrate sources. Dietary carbohydrate sources significantly affected body composition, and liver phosphoenolpyruvate carboxykinase (PEPCK), pyruvate kinase (PK), glucose 6‐phosphate dehydrogenase (G6PD) and malic enzyme (ME) activities also varied according to dietary carbohydrate complexity. Fish with different food habits showed different abilities to synthesize liver glycogen, and the liver glycogen content in gibel carp was significantly higher than in Chinese longsnout catfish. The influence of carbohydrate source on gluconeogenesis and lipogenesis was also different in the two fish species.  相似文献   

19.
A 60-days feeding trial was conducted to delineate the effect of both gelatinized and non-gelatinized corn with or without supplementation with exogenous α-amylase at two dietary protein levels (35% and 28%) on dry matter digestibility, digestive enzymes and tissue glycogen content of Labeo rohita juveniles. Three hundred and sixty juveniles (average weight 10±0.15 g] were randomly distributed into 12 treatment groups with each of two replicates. Twelve semi-purified diets containing either 35% or 28% crude protein were prepared by including gelatinized (G) or non-gelatinized (NG) corn as carbohydrate source with different level of microbial α-amylase (0, 50, 100 and 150 mg kg−1). The dry matter digestibility of G corn fed groups was significantly higher (P < 0.05) than that of the NG corn fed groups. Hepatosomatic index (HSI), liver glycogen and intestinal amylase activity of G starch fed groups were significantly higher (P < 0.05) than those of the NG corn fed groups. However, the reverse trend was found for gastrosomatic index (GSI), muscle glycogen and intestinal protease activity. Addition of 50 mg α-amylase kg−1 feed improved the dry matter digestibility of NG starch fed groups, which was similar to that of the G corn fed groups or NG corn supplemented with 100/150 mg α-amylase kg−1 feed. HSI, liver glycogen and intestinal amylase activity were significantly increased (P < 0.05) at minimum level of α-amylase in the feed (50 mg kg−1) and did not increase due to further inclusion of amylase in the diet. Supplementation with α-amylase at 50 mg kg−1 increased the intestinal amylase activity beyond which no significant changes were observed. Protease activity of liver and intestine was highest (P < 0.05) in higher crude protein (CP) fed groups, but protease activity of the intestine was significantly higher in the α-amylase supplemented groups. Hence, it was concluded that feed with 28% CP containing either G corn without α-amylase or NG corn with 50 mg α-amylase kg−1 may be used as the alternative carbohydrate source for L. rohita juveniles.  相似文献   

20.
The effect of various dietary starch to proteins ratios (STA/P) on growth performance, oxidative status and liver enzyme activities involved in intermediary metabolism in juvenile Nile tilapia was evaluated. Four isocaloric‐practical diets (12.73 MJ kg?1 digestible energy) with increasing STA/CP ratios were formulated. These were designated D0 (344 g crude protein (CP) and 163.5 g starch (STA) kg?1), D1 (310 g CP and 243 g STA kg?1), D2 (258 g CP and 322 g STA kg?1) and D3 (214 g CP and 401 g STA kg?1). Each diet was fed to triplicate groups of 60 fish (2.7 g) for 45 days. Compared with the control diet (D0), significantly (P < 0.05) depressed growth and feed efficiency were observed only in the groups fed on diet D3. The activities of hepatic enzymes involved in glycolysis and lipogenesis pathways were significantly enhanced in groups fed on diet D3 compared with other diets. A significant (P < 0.05) increase in catalase activity was detected only in groups fed on diet D3. Similarly, a significant (P < 0.05) enhancement in superoxyde dismutase, glutathione S‐transferases and glutathione peroxidise was observed in groups fed on diets D2 and D3 compared with other diets. Results demonstrate the ability of juvenile Nile tilapia to spare protein by dietary carbohydrate.  相似文献   

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