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1.
Zdeněk Adámek David Kortan Pavel Lepič Jaroslav Andreji 《Aquaculture International》2003,11(4):389-396
The increasing numbers of otters (Lutralutra L.), which are protected by the CzechAct of Nature and Landscape Protection, arecausing serious problems for fishpondmanagement. The diet of otters on pond farmsconsists predominantly (80%) of common carp,Cyprinus carpio, and to a lesser extentother pond fish species (perch, Percafluviatilis, zander, Stizostedionlucioperca and grass carp, Ctenopharyngodon idella). The size of carpcaptured by otters ranged between 376–683 mmTL (500 ± 88 mm) and 1,049–11,768 g(3,478 ± 2,867 g). Reconstructed originalweight and length of captured grass carp andperch were 599 and 182 mm TL, and 2,665 and163 g, respectively. In most of prey fishcorpses left by otters, only viscera andassociated parts were consumed. The weight ofindividual common carp corpses was estimated as73.0 ± 24.6 (26.3–95.9)% of theoriginal reconstructed weight, which means thatonly 27.0 ± 17.2 (4.1–73.7)% of fishbody mass was consumed by otters. In perch,62.8% of fish body mass was left unconsumed.Heavy losses have been reported also on fishstocks in ice-covered ponds during the winterperiod, when shoals of resting fish have beendisturbed and stressed due to otter hunting. 相似文献
2.
Imtiaz Ahmed 《Fish physiology and biochemistry》2007,33(3):203-212
An eight-week feeding trial has been conducted to determine the optimum ration for Indian major carp, Labeo rohita, fingerling (4.10 ± 0.30 cm, 0.55 ± 0.16 g) by feeding a purified diet (40% CP; 3.61 kcal g−1 GE) at six levels, 2, 4, 6, 8, 10, and 12% of body weight per day, at 0800 and 1600 h, in triplicate, to 20 fish per trough
fitted with a water flow-through system. Highest weight gain, best feed conversion ratio (FCR), best specific growth rate
(SGR%), and highest protein efficiency ratio (PER) were evident for rations of 6–8% body weight. Second-degree polynomial
regression analysis for FCR, PER, protein, and energy retention data indicated the break-points occurred at 6.55, 6.75, 6.80,
and 6.95% bw per day, respectively. Significant (P < 0.05) differences between body composition were observed for fish fed different rations. Maximum body protein content was
recorded for 6% and 8% rations. A linear increase in body fat content was evident with increasing ration. Body moisture and
ash content remained non-significantly (P > 0.05) low for higher rations, however. On the basis of these results it is recommended that feeding in the range 6.5–7.0% bw
per day corresponding to 2.6–2.8 g protein and 23.49–25.31 kcal energy per 100 g of the diet per day is optimum for growth
and efficient feed utilization of Labeo rohita. Results for 2–4% rations (0.8–1.6 g protein and 7.23–14.46 kcal energy) suggest these amounts approximate to the maintenance
requirement of this fish. 相似文献
3.
低鱼粉饲料中添加牛磺酸对青鱼幼鱼生长、肠道修复及抗急性拥挤胁迫的影响 总被引:4,自引:2,他引:2
为研究低鱼粉饲料中添加牛磺酸对青鱼幼鱼[初始质量(5.90±0.03)g]生长、肠道修复及抗急性拥挤胁迫的影响,实验以青鱼正常鱼粉组(20%)为对照组,10%鱼粉组为负对照组(I_0组),在低鱼粉饲料中分别添加0.05%(I_(0.05)组)、0.1%(I_(0.1)组)、0.2%(I_(0.2)组)、0.4%(I_(0.4)组)牛磺酸,配制6种等氮等脂饲料,饲养8周。饲养实验结束后,参考生长结果,选择对照组、I_0组、I_(0.1)组、I_(0.4)组进行急性拥挤胁迫实验。结果显示:①与对照组相比,I_0组增重率显著下降,随着低鱼粉饲料中牛磺酸水平的升高,青鱼幼鱼增重率呈先上升后下降趋势,当牛磺酸添加量为0.1%时与对照组差异不显著;②相对于对照组,I_0组的绒毛高度降低、隐窝深度增加,杯状细胞数降低,添加牛磺酸使绒毛高度升高、隐窝深度降低,杯状细胞数和淋巴细胞数增多;③急性拥挤胁迫使青鱼幼鱼血清史质醇、血糖、血清溶菌酶(LSZ)、补体C3、超氧物歧化酶(SOD)和谷胱甘肽(GSH)含量均呈先升高后下降的趋势,其最大值出现在胁迫2 h或者8 h。在整个胁迫期间,I_0组史质醇和血糖含量高于其他各饲料组,I_0组溶菌酶、补体C3、SOD和GSH均低于其他各饲料组。研究表明,在低鱼粉饲料中添加牛磺酸可提高青鱼生长性能、改善肠道结构、增强青鱼的抗急性拥挤胁迫的能力。 相似文献
4.
S. He Z. Wu Y. Liu N. Wu Y. Tao L. Xu Z. Zhou B. Yao E. Ring 《Aquaculture Nutrition》2013,19(5):765-772
Dried distiller's grain (DDG) is considered as an alternative ingredient of dietary feed due to its high contents of protein, fibre and fat. In this study, 60 g kg‐1 of DDG was used to feed grass carp (Ctenopharyngodon idella), bluntnose black bream (Megalobrama amblycephala), gibel carp (Carassius gibelio) and black carp (Mylopharyngodon piceus) for 8 weeks, and its effect on fish production and gut allochthonous microbiota was investigated for the development of a suitable fish feed high in nutrients and low in cost for polyculture freshwater fish. DDG supplementation resulted in the less weight gain and higher feed conversion ratio of black carp (P < 0.05), but had no significant effects on other fish or parameters. PCR–denaturing gradient gel electrophoresis (DGGE) analysis indicated that all four fish species had some common and unique bacteria in their digestive tracts, and the gut microbiota of bluntnose black and gibel carp fed the control diet and DDG diets were very similar (Cs > 91%); of them, the total counts of intestinal bacteria studied by qPCR increased in grass carp (P < 0.05) and depressed in black carp (P < 0.05) when fed dietary DDG. Thus, we assumed that dietary DDG modulated production and gut microbiota of fish in a host‐specific way. 相似文献
5.
The effect of prebiotic xylooligosaccharides (XOS) on the growth performance and digestive enzyme activities of the allogynogenetic
crucian carp, Carassius auratus gibelio, was investigated. XOS was added to fish basal semi-purified diets at three concentrations by dry feed weight: diet 1, 50 mg kg−1; diet 2, 100 mg kg−1; diet 3, 200 mg kg−1, respectively. Twelve aquaria (n = 20) with three replicates for each treatment group (diets 1–3) and control treated without XOS were used. Weights of all
collected carp from each aquarium were determined at the initial phase and at the end of the experiment, and the carp survival
was also determined by counting the individuals in each aquarium. After 45 days, there were significant differences (P < 0.05) in the relative gain rate (RGR), and daily weight gain (DWG) of diets 1–3 were compared with the control. However,
the survival rate was not affected (P > 0.05) by the dietary treatments. For enzymatic analysis, dissection produced a crude mixture of intestine and hepatopancreas
of each segment to measure. The protease activity in the intestine and hepatopancreas content of fish in diet 2 (487.37 ± 20.58 U g−1 and 20.52 ± 1.93 U g−1) were significantly different (P < 0.05) from that in the control (428.13 ± 23.26 U g−1 and 12.81 ± 1.52 U g−1) and diet 3 (428.00 ± 23.78 U g−1 and 14.04 ± 1.59 U g−1). Amylase activity in the intestine was significantly higher for diet 2 compared to diet 1 and the control. As for amylase
in the hepatopancreas, assays showed higher activity in diet 2 (P < 0.05) compared to the rest. 相似文献
6.
Shi-Jian Fu 《Fish physiology and biochemistry》2007,33(2):135-141
The growth performance of carnivorous southern catfish (Silurus meridionalis) was lower when fed a diet containing glucose as a carbohydrate source than when fed one containing starch. To test whether
this decreased growth performance was partly due to higher metabolic costs induced by the fast assimilation of dietary glucose,
the postprandial metabolic responses of southern catfish juvenile (36.7 ± 1.9 g) fed diets containing either raw or pre-cooked
corn starch and glucose were investigated at 27.5°C. The peak metabolic rate of fish fed a raw corn starch diet was significantly
higher than that of fish fed precooked corn starch and glucose diets (P < 0.05). The specific dynamic action (SDA) coefficients (energy expended on SDA as a percentage of energy content of the
meal) of fish fed raw or precooked corn starch diets were significantly higher than that of fish fed a glucose diet (P < 0.05). The postprandial metabolic rate of fish fed a raw starch diet displayed a classic response – increased metabolic
rate immediately after feeding, followed by a decreased metabolic rate several hours after feeding – as has been documented
earlier in this species. However, the postprandial metabolic rate of fish fed a glucose diet had two alternating cycles of
increasing and decreasing metabolic rate, which has not been reported previously. This bimodal pattern of the SDA curve was
also found in a subsequent experiment in which purified d-glucose (0.1 g dry mass) was packed into sections of grass carp (Ctenopharyngodon idellus) intestine (0.05 g dry mass). The results suggest that the digestibility and absorption speed of the dietary carbohydrate
has a significant effect on postprandial metabolic response in juvenile southern catfish. The results of this study may provide
useful data in terms of the utilization of dietary carbohydrates by carnivorous fishes. 相似文献
7.
Shmuel Rothbard William L. Shelton Zeev Kulikovsky Israel Rubinshtein Yair Hagani Boaz Moav 《Aquaculture International》1997,5(1):51-64
The mollusc-eating black carp (Mylopharyngodon piceus) has economic and health-care potential for biological control of nuisance aquatic molluscs. The present study investigates
the production of gynogenetic-monosex and triploid-sterile populations of black carp. The goal was to provide a method which
would eliminate unwanted biological and environmental impacts of introducing this exotic species into areas with nuisance
mollusc infestation. Meiotic gynogenesis was induced by inseminating black carp eggs with UV-irradiated (800 Jm−2) sperm of common carp (Cyprinus carpio) or Japanese ornamental (koi) carp. Diploidy was restored through retention of the second polar body (2PB), by shocking activated
eggs at 1–8 min post-fertilization (embryological age of 0.07–0.57τ0, a parameter defined by the cell cycle duration) at 1 min intervals, with heat-shocks (41.0±1.0 °C for 1 min) or pressure-shocks
(7500–7600 psi for 1.5 min). Highest survival was found when embryos were heat-shocked 1.5–4.5 min post-fertilization (0.10–0.25τ0). The highest survival of free-swimming larvae from pressure-shocked eggs, was achieved at 7500 psi at 1–2 min post-fertilization
(0.08–0.16τ0). Triploidy was induced by retention of 2PB following normal fertilization. Batches of 30 000 eggs were fertilized with intact
sperm and pressure-shocked (6000–8500 psi for 1.5 min) 2 min post-fertilization (0.15–0.16τ0). The highest survival of triploid swim-up larvae was 5.1% in eggs shocked with 7500 psi. In random samples of individual
larvae taken from each treatment, triploidy was analysed by cytofluorometry of the cellular DNA content. In DNA analysis performed
in fingerlings (N≥15), 50% of the fish were triploids. 相似文献
8.
The gonad histology, gonado-somatic index (GSI), 17β-estradiol (E2) levels and acetylcholinesterase (AChE) activity in the carp species Chalcalburnus tarichi from Lake Van and the Karasu river, eastern Turkey, have been investigated. Fish between 5 and 7 years old were sampled from
November 2003 to February 2004. The ratio of female fish caught in Lake Van with abnormal ovaries (AbOF) was 43.3%, but the
fork length and body weight of these fish were not correlated with this abnormality. The weight of the ovaries and the GSI
values of AbOF were very low (P < 0.05). Histological observations on the samples caught each month revealed that the oocytes had degenerated in the perinucleolus
and early cortical alveolus stages and that the ovaries were full of somatic stromal tissue. In addition, the seminiferous
tubules of male fish with abnormal testes did not contain male reproductive cells at any stage. The ovaries of the fish caught
from the Karasu river were also full of oocytes in the perinucleolus and early cortical alveolus stages, but there were fewer
atretic follicles. Furthermore, apoptosis was observed in the ovary cells of these fish, in particular in the follicular cells,
and the plasma E2 levels of the AbOF was very low (P < 0.05). AChE activity was inhibited only in liver (P < 0.05). We conclude that our sample of C. tarichi must have been exposed to various polluting chemicals or another unknown factors (such as global warming) and that these
factors have irreversibly impaired oocyte development in a high percentage of fish. 相似文献
9.
J. W. Huang L. X. Tian Z. Y. Du H. J. Yang Y. J. Liu 《Fish physiology and biochemistry》2007,33(2):167-172
This study was conducted to evaluate the effects of dietary thiamin on the physiological status of the juvenile grouper, Epinephelus coioides. Graded levels of thiamin (0.08, 0.50, 2.12, 3.15, 4.63, 12.37 mg thiamin kg−1 diet) were fed to grouper juveniles (mean weight: 16.97 ± 0.14 g) for 10 weeks. Although fish fed the thiamin-deficient (TD)
diet showed no obvious symptoms of thiamin deficiency or increased mortality, those fed the lowest doses of thiamin (0.08
and 0.50 mg thiamin kg−1 diet) had significantly decreased transketolase activity in the liver. In addition, the level of liver thiobarbituric acid
reactive substances in fish fed the TD diet was 33–67% higher than that in fish with the thiamin-supplemented diet. There
were no significant differences in superoxide dismutase activity between the different groups of fish. 相似文献
10.
11.
J. Máchová M. Prokeš Z. Svobodová V. Žlábek M. Peňáz V. Baruš 《Aquaculture International》2007,15(3-4):267-276
Diazinon 60 EC (chemical insecticide, organophosphate, active substance diazinon at a concentration of 600 g l−1) is used in fish-farming in well-founded cases as a biocide to suppress excessive propagation of coarse Daphnia zooplankton.
At the concentration of 10 μg l−1 (i.e., 100 g per 1 ha at a mean depth of the pond of 1 m), Diazinon 60 EC can highly selectively eliminate Daphnia zooplankton,
causes no harm to fish, and relatively quickly decomposes in the aquatic environment. This has been corroborated by results
of acute toxicity tests in fish: the 96 h LC50 is 3 mg l−1 for the guppy (Poecilia reticulata) and 10–25 mg l−1 for the common carp (Cyprinus carpio). As demonstrated by embryonic and larval tests of toxicity for the common carp (C. carpio), Diazinon 60 EC at the concentration of 10 μg l−1 causes no harm to the tested, individuals even in these sensitive (critical) stages of ontogeny. 相似文献
12.
Zhen-Yu Du Yong-Jian Liu Li-Xia Tian Jian-Guo He Jun-Ming Cao Gui-Ying Liang 《Aquaculture International》2006,14(3):247-257
An 8 weeks growth study was conducted to estimate the optimal feeding rate for juvenile grass carp (3.08±0.03 g, mean ± SD). Fish were fed with a casein purified diet (360 g protein, 56 g lipid and 3000 kcal total energy/kg dry diet) at six feeding rates: 1.0, 1.5, 2.0, 2.5, 3.0, 3.5% body weight per day (BW d−1). Each feeding rate was randomly assigned to three tanks of fish with 30 fish per tank (50W × 50H × 100L, cm). Fish were maintained in recirculating systems at a water temperature of 24.97±2.23 °C and were fed four times per day. After 2 weeks, fish fed on 3.5% BW d−1 could not finish the diet and this treatment was cut-off. Analysis of variance showed that growth performance was significantly (p<0.05) affected by different feeding rates. The nutrient compositions of whole body, muscle and liver were also significantly different among treatments. The body weight gain (WG), specific growth rate (SGR), feed efficiency (FE), protein efficiency ratio (PER), apparent digestibility coefficiency (ADC), retention of protein (PR), mesenteric fat index, body moisture and protein content were significantly (p<0.05) affected by feeding rate. The WG, SGR and digestion rate were highest at 2% BW d−1, although the FE and PER decreased with increasing feeding rate. Broken line analysis on specific growth rate indicated that the optimum feeding rate of juvenile grass carp is 1.97% body weight day−1. 相似文献
13.
Alessio Bonaldo Gloria Isani Ramon Fontanillas Luca Parma Ester Grilli Pier Paolo Gatta 《Aquaculture International》2010,18(5):909-919
Three isoproteic (47% protein) diets were formulated to contain graded levels of crude fat (diet D16:16%, diet D24: 24% and
diet D32: 32%). Each diet was fed to satiation in three and to 80% satiation in two replicate groups of gilthead sea bream
(Sparus aurata), having an initial body weight of 72–74 g. The trial lasted 81 days. Groups fed to satiation showed higher final body weight
(FBW; 238.8–252.3 g vs. 218.0–229.3 g) and daily growth index (DGI; 2.49–2.65%/day vs. 2.27–2.34%/day) than those fed to 80%
satiation. Feed intake was significantly different both for feeding level and for diet composition. Fish fed to satiation
had higher feed conversion rate (FCR) compared to the 80% satiation groups (1.33–1.44 vs. 1.13–1.17; P ≤ 0.001). Within satiation groups, FCR was significantly lower in fish fed D16 compared to fish fed D32 (1.33 vs. 1.44, P ≤ 0.05), whereas no statistical differences were found within the 80% satiation groups. The increase in dietary lipid level
did not improve growth performance, feed efficiency and protein utilization but decreased gross lipid efficiency. Conversely,
a reduction in ration from satiation to 80% satiation decreased DGI, thus improving FCR. Feed costs were influenced by dietary
energy level and feeding ratio, the lowest energy diet at 80% satiation being the most profitable combination among the variables. 相似文献
14.
Fish that have escaped from a cormorant’s (Phalacrocorax carbo sinensis (L.)) grasp and/or which could not be swallowed due to their size suffer from various injuries resulting in consecutive infections
and subsequent increased mortality. Computer-assisted image analysis was applied to describe the extent of such injuries.
Two-year-old mirror carp, Cyprinus carpio L. (TL 200–300 mm, W 200–300 g) showed injuries ranging over approximately 10% of the total body surface. Immediately after wounding, the damaged
epithelium (scars) cover 5–35%, and deeper subdermal wounds caused by the beak tip pervading into muscle tissue cover an area
of 1–2% of the total body surface. On the side impacted by the cormorant’s lower mandible, extensive areas of epidermal contusions
(scars) occur. As time progresses, these ratios change—deeper necroses represent up to 10% of the total body surface and healing
epithelial scars comprise just 1–2%. In wounded silver carp, Hypophthalmichthys molitrix Val. (300–400 mm, W 500–700 g), the share of subdermal wounds usually does not exceed 0.5% due to their compact scaly cover. During pond draining
due to fish harvesting, the size spectrum of wounded fish increases and may also often include bigger fish (e.g., European
catfish, Silurus glanis L.) up to 2.2 kg. 相似文献
15.
Supplemental cereal feeding (maize, wheat and triticale compared with a control group with natural food only) and its effect
on fatty acid (FA) expression in the flesh during long-lasting storage of common carp (Cyprinus carpio) was investigated. The fish were cultured in earthen ponds in the Trebon region (Czech Republic). The content of fatty acid
was investigated in the flesh of carp during 8 months of long-lasting storage without additional feeding. Sixty common carp
in their third year of life were used for the analyses. The weight of the fish (marketable fish) ranged from 1,358 g to 2,221 g.
Polyunsaturated fatty acid (PUFA, n–3) content and composition in fish flesh were determined by gas chromatography (VARIAN 3300). Supplemental cereals caused
lower levels of PUFAs and n–3 PUFAs in fish fat. The content of these fatty acids did not decrease, even during 8 months of fish storage. The average
percentage of PUFAs in total fat from edible parts was: for maize 13.7% ± 1.58%, for wheat 11.6% ± 1.17% and for triticale
10.7% ± 1.00%. The percentage of n–3 PUFA for maize was 2.5% ± 0.36%, for wheat 3.38% ± 0.44% and for triticale 3.1% ± 0.39%. 相似文献
16.
EWA KAMLER LESZEK MYSZKOWSKI RAFAŁ KAMIŃSKI MICHAŁ KORWIN-KOSSAKOWSKI JACEK WOLNICKI 《Aquaculture International》2006,14(1-2):99-111
Duplicate groups of tench (Tinca tinca) juveniles (mean weight 0.69 g) were fed at 28 °C for 70 days either a commercial formulated diet, Futura, or frozen Chironomidae
larvae at four levels: below satiation, at about satiation, above satiation and well above satiation. These are represented
by the feeding groups F1–F4 and C1–C4, respectively. No mortality was observed throughout the experiment. In groups F2–F4
a considerable incidence of uneaten food (>40% observations), deformities of the caudal penduncle, retarded growth, elevated
condition coefficient (>1.2), reduced amounts of minerals in the tissue (<10% dry matter), high C/N ratio (>5) and high caloric
value of the tissue (>28 J mg−1 dry matter) (the latter two suggesting excessive fat deposits), were found. The combination of these indices was indicative
of overfeeding in fish fed the Futura diet at the daily doses ≥2.7% fish biomass. First symptoms of overfeeding: a considerable
incidence of uneaten food, retarded growth, and elevated C/N ratio were observed in the group fed Chironomidae larvae at the
highest level, (C4, wet Chironomidae 20.7% of the fish biomass daily, that is, 3.9% of dry chironomids per fish biomass and
day). Thus, restricted daily doses of formulated diet not exceeding 2.5% fish biomass are recommended for tench juveniles
aged 130–200 days post hatch. Safe daily doses of frozen Chironomidae (in terms of larvae dry weight) remain below 3.5% of
fish biomass. 相似文献
17.
Shiba Shankar Giri Sangram Ketan Sahoo Satyendra Nath Mohanty 《Aquaculture International》2010,18(4):539-544
An 84-day feeding trial was conducted to study the effect of replacing dietary fishmeal with dried chicken viscera meal (CVM)
on the growth (net biomass gain, specific growth rate, SGR), feed acceptability, feed conversion ratio (FCR), protein efficiency
ratio (PER) and carcass composition of Clarias batrachus fingerlings. Triplicate groups of fingerlings with mean initial body weight of 13.35 g were fed on six iso-nitrogenous and
iso-lipidic diets. The control diet (CVM0) used marine by-catch fishmeal as the sole source of animal protein. In the other
five diets (CVM100–CVM500), 20–100% of fishmeal was substituted by dried CVM at 20% increments. The highest body weight gain,
SGR and PER, and the lowest FCR were observed in fish fed a diet containing 300–500 g CVM kg−1. The fish accumulated increasing quantities of lipids and decreasing levels of ash in their carcasses with increasing levels
of dietary CVM. 相似文献
18.
Marek Matras Magdalena Stachnik Ewa Borzym Joanna Maj‐Paluch Michal Reichert 《Journal of fish diseases》2019,42(7):959-964
During a PCR‐based CEV survey in Poland in 2015–2017, the virus was detected in many farms both in clinical and asymptomatic cases and in common as well as in koi carp (Cyprinus carpio). In order to evaluate the potential carrier role of fish species that share the same habitats with carp, an experimental trial was performed. Investigations carried out on specimens of bleak (Alburnus alburnus), crucian carp (Carassius carassius), European perch (Perca fluviatilis), Prussian carp (Carassius gibelio), roach (Rutilus rutilus) and tench (Tinca tinca) cohabited with CEV‐infected carp yielded positive results. These species of fish were experimentally cohabited with CEV‐infected common carp at a temperature of 16°C ± 1. Material from the brain, gills, spleen, kidneys, intestine and skin was investigated for the presence of CEV DNA. Similar investigations were performed with uninfected fish designated controls. Samples were tested for CEV by qPCR. 相似文献
19.
The diet of juvenile (predominantly age 1) southern bluefin tuna Thunnus maccoyii (SBT, N = 720), caught over 11 years of the recruitment monitoring survey off southern Western Australia during summer, consisted
overwhelmingly of teleosts (97.4% by volume). Pilchard Sardinops sagax (27.4%V), blue mackerel Scomber australasicus (16.7%V), and jack mackerel Trachurus declivis (14.2%V) were the major taxa, with pilchard more abundant in coastal waters and jack mackerel more frequently encountered in fish
caught closer to the shelf-edge. Prey size varied from 5 to 240 mm, with 67% of ingested items measuring between 30 and 50 mm.
Pilchard dominated the prey size category 130–190 mm (84% by number), but the overall contribution of this species to the
diet of juvenile SBT was much lower than previously reported. Future research in relation to the feeding ecology of juvenile
SBT should focus on the biology and ecology of the young lifestages of the main prey species in this area and on prey distribution
and dynamics as a key factor linking environmental change and SBT distribution. 相似文献
20.
W. GAO Y.‐J. LIU L.‐X. TIAN K.‐S. MAI G.‐Y. LIANG H.‐J. YANG M.‐Y. HUAI W.‐J. LUO 《Aquaculture Nutrition》2011,17(1):2-12
Two, 8‐week feeding trials were conducted to compare protein‐sparing capability of dietary lipid in herbivorous grass carp (Ctenopharyngodon idella) and omnivorous tilapia (Oreochomis niloticus × O. aureus). Utilizing a 2 × 3 factorial design, experimental diets containing two levels of crude protein (380 and 250 g kg−1) and three levels of lipid (0, 40 and 100 g kg−1) were formulated for use in both feeding trials. Growth performances showed better response of both fish fed 380 g kg−1 protein diet than those fed 250 g kg−1 protein diet. Despite the dietary protein level, weight gain (WG), specific growth ratio (SGR), feed conversion ratio (FCR) and protein efficiency ratio were much higher (P < 0.05) for grass carp fed 40 g kg−1 lipid diet than those fed 100 g kg−1 lipid diet; however, there were no significant differences in tilapia fed the two diets. The feed intake of grass carp fed lipid‐free diet was the lowest, but it tended to decrease with increase in dietary lipids in tilapia. Lipid retention (LR) was negatively correlated with dietary lipid concentration of both fish. Viscerosomatic index (VSI), hepatosomatic index (HSI), intraperitoneal fat ratio (IPF) and whole‐body and liver lipid content positively correlated with dietary lipid concentration of both fish. Plasma parameters and liver enzymes activities were also positively correlated with dietary lipid concentration of both fish. Liver lipid contents were higher and enzymes activities were lower in grass carp when compared with tilapia. These data suggested that there was no evidence of a protein‐sparing effect of dietary lipids in grass carp. Tilapia has relatively higher capacity to endure high dietary lipid level compared to grass carp. 相似文献