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1.
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   

2.
This study was conducted to evaluate the effects of dietary riboflavin on antioxidant defense in the juvenile grouper Epinephelus coioides. Graded levels of riboflavin (0.9, 1.6, 4.4, 6.7, 12.9 and 19.4 mg kg−1 dry diet) were fed to grouper juveniles (mean weight: 14.90 ± 0.46 g) for 12 weeks. Higher levels of liver thiobarbituric acid reactive substances (TBARS) content were observed in grouper fed low doses (0.9 and 1.6 mg kg−1 diet) of riboflavin. Both liver glutathione reductase (GR) activity and its activation coefficient (GR-AC) poorly responded to riboflavin deficiency. In addition, other indices of the glutathione-dependent defense system, including the activities of glutathione peroxidase (GSH-PX) and glutathione-S-transferase (GST), and the content of glutathione (GSH), were also non-significantly affected by dietary riboflavin levels. However, the activities of liver superoxide dismutase (SOD) and catalase (CAT) were significantly lower in fish fed 0.9 mg kg−1 diet, with a positive correlation between the different groups. In conclusion, the present study indicated that the juvenile grouper fed the riboflavin-unsupplemented diet was susceptible to lipid peroxidation (LPO), with lower SOD and CAT activities in the liver. However, the glutathione-dependent defense system of grouper was not affected by dietary riboflavin levels.  相似文献   

3.
In order to assess the effect of dietary pyridoxine supplementation on the growth performance of Nile tilapia and the haematological response under heat stress, 192 fingerlings (8.41 ± 0.22 g) were randomly distributed into eight tanks and fed practical diets supplemented with increasing levels of pyridoxine (0.0; 5.0; 10.0 and 20.0 mg of pyridoxal HCl kg?1 diet) for 91 days. The fish were then weighed and the diet was quantified to determine the growth performance [weight gain (WG), feed intake, feed conversion ratio, protein efficiency rate, protein retention (PR) and survival percentage]. Haematological analyses (red blood cell count, haematocrit, haemoglobin, total leucocyte and differentiation, mean corpuscular volume, mean corpuscular haemoglobin concentration, albumin, globulin and albumin/globulin ratio) were carried out and then 32 fish were transferred and subjected to heat stress (32 °C) for 3 days, after which the haematological parameters were analysed. The fish fed the unsupplemented diet showed the lowest WG and PR. For the normal growth and health of the Nile tilapia, the Pyridoxine requirement in a practical diet is 10.0 mg of pyridoxine HCl kg?1.  相似文献   

4.
The purpose of this study was to determine the effect of Angelica sinensis polysaccharide (ASP) supplemented in diet on the innate cellular immune response and disease resistance in grouper, Epinephelus malabaricus. Fish were fed diets containing different doses of ASP (0, 500 and 3,000 mg kg−1 diet) for 12 weeks. After 12 week feeding, the respiratory burst activity, phagocytic activity, and leukocytes proliferation in head kidney were assayed. The functional immunity in terms of cumulative mortality was also assessed by a challenge with live Edwardsiella tarda. Results showed that the respiratory burst activities in ASP-supplemented groups were increased significantly. The respiratory burst index was the highest in fish-fed 3000 mg kg−1 diet and the lowest in control. The phagocytic activities in ASP-supplemented groups were significantly higher than that of control. No significant difference in phagocytic activity was observed between ASP-supplemented groups. ASP stimulated the head kidney leukocytes proliferation significantly, despite the absence of lipopolysaccharide (LPS) or not. The cumulative mortalities of fish fed with 3000 mg ASP kg−1 diet were significantly lower than those fed with 500 mg ASP kg−1 diet and control diet after 96 h of challenge. In conclusion, dietary ASP enhanced some cellular immune parameters and disease resistance against E. tarda in grouper.  相似文献   

5.
An experiment was conducted to investigate the effect of dietary chromium picolinate supplement on growth and haematology parameters of grass carp, Ctenopharyngodon idellus. Six diets with increasing dietary chromium picolinate levels 0, 0.2, 0.4, 0.8, 1.6 and 3.2 mg kg−1 were fed to triplicate groups of 20 fish (initial weight of 12.78 ± 1.16 g, mean ± SD) in a flow water system for 10 weeks. Fish fed the diet supplemented with 0.8 mg Cr kg−1 had significantly improved weight gain (WG), feed efficiency ratio (FER), protein efficiency ratio (PER) and protein retention (PR). Fish fed high-chromium diets exhibited lower whole-body crude lipid contents than fish fed low-chromium diets. Liver glycogen concentrations for fish fed the diet with 0.2 mg Cr kg−1 was the highest (77.67 mg g−1). Fish fed the diet supplemented with 1.6 and 3.2 mg Cr kg−1 had significantly lower liver glycogen concentrations than other groups (P < 0.05). The highest serum insulin concentrations were observed in fish fed the diet supplemented with 0.8 mg Cr kg−1, but serum insulin concentrations decreased (P < 0.05) when dietary supplementation of chromium was higher than 0.8 mg Cr kg−1. Cholesterol concentrations decreased in direct proportion to dietary chromium level and achieved the lowest level when the fish were fed the 0.8 mg Cr kg−1 diet, but increased when the fish were fed the diet with more than 0.8 mg Cr kg−1 (P < 0.05). Fish fed the diet supplemented with 0.8 mg Cr kg−1 had higher triglyceride and high-density lipoprotein cholesterol (HDL-C) concentrations compared to other treatments. The results of the present study suggested that chromium picolinate could modify serum carbohydrate and lipid metabolism profile, and that the optimal dietary chromium level was 0.8 mg kg−1 for grass carp according to growth.  相似文献   

6.
An experiment was conducted to investigate the effect of dietary iron supplement on growth, haematology and microelements of juvenile grouper, Epinephelus coioides. Casein–gelatine‐based diets supplemented with 0, 50, 100, 150, 200 and 250 mg kg−1 iron from ferrous sulphate were fed to grouper (mean initial weight: 21.0 ± 0.2 g) for 8 weeks. Weight gain was highest in fish fed the diet supplemented with 100 mg kg−1 iron, intermediate in fish fed diets with 50, 150, 200 and 250 mg kg−1 iron and lowest in fish fed the basal diet. Feed efficiency followed a similar trend except that the lowest value was in fish fed the basal diet and the diet supplemented with 250 mg kg−1 iron. Hepatic iron was highest in fish fed diets supplemented with iron ≥100 mg kg−1, followed by fish fed diet with 50 mg kg−1 iron and lowest in fish fed the basal diet. The whole‐body iron was lowest in fish fed the basal diet but not significantly different from other groups, as judged by anova . Iron supplement to the basal diet had no significant effect on haematological parameters (red blood cell count, haematocrit and haemoglobin), hepatic copper concentration or manganese, zinc concentration in liver and whole body. Broken‐line analysis of hepatic iron indicated that iron supplementation of 100 mg kg−1 satisfied the hepatic iron storage and that further supplementation did not expand the iron status.  相似文献   

7.
In this study, we have investigated the effects of Porphyridium cruentum (Rodophyta) as a natural pigment source and astaxanthin and β-carotene as synthetic pigment sources on the skin colour of cichlid fish (Cichlasoma severum sp., Heckel 1840), which are generally light orange with white patches and becomes shiny orange in the reproductive phase. The fish were fed diets containing 50 mg kg−1 astaxanthin and β-carotene, and P. cruentum powder. The amount of both natural and synthetic pigment sources given as feed was 50 mg kg−1, and the experiment was continued for 50 days. Total carotenoid content of the fish was determined spectrophotometrically at the end of the experiment. As a result, while a visible change of colour in the skin of the fish fed on the feed containing astaxanthin was observed with 0.34 ± 0.2 mg g−1 of pigment accumulation, a relatively small change of colour was observed in the skin of other fish that were fed on the feed containing P. cruentum and β-carotene with 0.22 ± 0.2 mg g−1 and 0.26 ± 0.1 mg g−1 of pigment accumulations, respectively. Therefore, it was determined that these pigment sources have an effect on the colour of cichlid fish.  相似文献   

8.
The effects of different ratios of dietary raw to pre-gelatinized starch on the growth performance, feed utilization and body composition of juvenile yellowfin seabream (Sparus latus) were evaluated during a 10-week growth trial. Five isonitrogenous, semi-purified diets containing 200 g kg−1 starch comprising different ratios of raw to pre-gelatinized starch [(in g kg−1)100:100 (diet 1), 150:50 (diet 2), 50:150 (diet 3), 200:0 (diet 4), 0:200 (diet 5), raw:pre-gelatinized] were prepared and fed to triplicate groups of juvenile S. latus. Our results showed that fish fed diet 4 (200 g kg−1 raw starch) had the highest weight gain and specific growth rate, followed by those fed diet 2, diet 1, diet 3 and diet 5. Feed efficiency, protein efficiency ratio and protein productive value in the fish on diets 4 and diet 2, respectively, were significantly higher than those on diets 3 and diet 5, respectively. Body and muscle compositions were unaffected by the different dietary raw to pre-gelatinized starch ratios. Values of hepatosomatic index, intraperitoneal fat ratio, viscerosomatic index and condition factor did not vary among experimental treatments. Plasma indices showed variations, but these were not relative to dietary treatments. In conclusion, the partial or total replacement of raw starch by pre-gelatinized starch in diets for yellowfin seabream did not improve its growth performance and feed utilization.  相似文献   

9.
An 8‐week feeding trial was conducted to determine two vitamin C derivatives, l ‐ascorbyl‐2‐sulphate (C2S) and l ‐ascorbyl‐2‐polyphosphate (C2PP), to satisfy vitamin C requirement and to test their effects on the non‐specific humoral immune responses of juvenile grouper, Epinephelus malabaricus. C2S and C2PP were each supplemented at 20, 50, 80, 150, 250 and 400 mg kg?1 diet in the semi‐purified basal diet providing of 7, 16, 28, 55, 86, 142 mg ascorbic acid (AA) equivalent of C2S kg?1 diet and 4, 9, 15, 31, 49, 75 mg AA equivalent of C2PP kg?1 diet, respectively. Basal diet without AA supplemented was included as a control. Each diet was fed to triplicate groups of grouper (mean initial weight: 6.69 ± 0.07 g). Fish fed diets with ≥28 mg AA equivalent of C2S or ≥4 mg AA equivalent of C2PP kg?1 had significantly (P < 0.05) greater weight gain (WG) than fish fed the unsupplemented control diet. Liver AA concentrations were higher in fish fed diets with ≥16 mg AA equivalent of C2S or ≥9 mg AA equivalent of C2PP kg?1 than fish fed the control diet. Alternative pathway of complement activation (ACP) was higher in fish fed diets with ≥55 mg AA equivalent of C2S or ≥15 mg AA equivalent of C2PP kg?1 than fish fed the control diet. Lysozyme activity was higher in fish fed ≥86 mg AA equivalent of C2S or ≥15 mg AA equivalent of C2PP kg?1 than fish fed the control diet. Analysis by broken‐line regression of WG indicated that the adequate dietary vitamin C concentration from each vitamin C derivative in growing grouper is 46.2 mg AA equivalent of C2S kg?1 diet and 17.8 mg AA equivalent of C2PP kg?1 diet, and it also indicated that C2S is approximately 39% as effective as C2PP in meeting the vitamin C requirement for grouper. The data suggest that both C2S and C2PP supplementation support non‐specific immune responses of grouper.  相似文献   

10.
Asian catfish, Clarias batrachus, were fed semi-purified basaldiets containing 0, 0.1, 0.5, 1, 3 and 5 mg biotin kg–1diet for 60 days. Fish fed the control diet (no biotin) showed(P < 0.05) higher mortality, lower weight gain, specificgrowth rate (SGR), feed efficiency ratio (FER) and protein efficiencyratio (PER) than in fish fed diets supplemented with biotin. The highestweight gain, SGR, FER and PER were noticed in fish fed 1 mg biotinkg–1, followed by 0.5, 5, 3 and 0.1 mg biotinkg–1, except for PER (followed by 0.5, 5, 0.1 and 3 mgbiotin kg–1). Quadratic analysis showed that the optimumdietary biotin requirements for maximal weight gain, PER and PER were2.49, 2.54 and 2.52 mg kg–1, respectively. Liver biotinconcentrations were influenced by levels of biotin in the diet.Concentration of liver biotin increased as level of dietarysupplementation increased and no biotin was detected in the liver of thecontrol fish. Liver pyruvate carboxylase and acetyl CoA carboxylaseactivities were higher in fish fed biotin-supplemented diets than incontrols. Biotin concentrations, pyruvate carboxylase and acetyl CoAcarboxylase activities in liver associated with normal growth rangedfrom 10.59 to 10.66 g g–1, 147.97 to 148.18 units mgprotein–1 and 12.76 to 12.78 units mg protein–1, respectively. Biotin deficiency symptoms such as anorexia, darkskin colour and convulsions were observed in fish fed the control diet.The optimum dietary biotin requirement for maximal growth of C.batrachus is about 2.49 mg kg–1 diet.  相似文献   

11.
Two experiments were conducted to quantify the dietary thiamin (experiment I) and pyridoxine (experiment II) requirements of fingerling Cirrhinus mrigala for 16 weeks. In experiment I, dietary thiamin requirement was determined by feeding seven casein–gelatin‐based diets (400 g kg?1 CP; 18.69 kJ g?1 GE) with graded levels of thiamin (0, 0.5, 1, 2, 4, 8 and 16 mg kg?1 diet) to triplicate groups of fish (6.15 ± 0.37 cm; 1.89 ± 0.12 g). Fish fed diet with 2 mg kg?1 thiamin had highest specific growth rate (SGR), protein retention (PR), RNA/DNA ratio, haemoglobin (Hb), haematocrit (Hct), RBCs and best feed conversion ratio (FCR). However, highest liver thiamin concentration was recorded in fish fed 4 mg thiamin kg?1 diet. Broken‐line analysis of SGR, PR and liver thiamin concentrations exhibited the thiamin requirement in the range of 1.79–3.34 mg kg?1 diet (0.096–0.179 μg thiamin kJ?1 gross energy). In experiment II, six casein–gelatin‐based diets (400 g kg?1 CP; 18.69 kJ g?1 GE) containing graded levels of pyridoxine (0, 2, 4, 6, 8 and 10 mg kg?1 diet) were fed to triplicate groups of fish (6.35 ± 0.37 cm; 1.97 ± 0.12 g). Fish fed diet containing 6 mg kg?1 pyridoxine showed best SGR, FCR, PR, RNA/DNA ratio, Hb, Hct and RBCs, whereas maximum liver pyridoxine concentration was recorded in fish fed 8 mg kg?1 dietary pyridoxine. Broken‐line analysis of SGR, PR and liver pyridoxine concentrations reflected the pyridoxine requirement from 5.63 to 8.61 mg kg?1 diet. Data generated during this study would be useful in formulating thiamin‐ and pyridoxine‐balanced feeds for the intensive culture of this fish.  相似文献   

12.
An 8‐week feeding trial was conducted to evaluate two vitamin C derivatives, L‐ascorbyl‐2‐monophosphate‐Mg (C2MP‐Mg) and L‐ascorbyl‐2‐monophosphate‐Na (C2MP‐Na), to satisfy the vitamin C requirement and to test their effects on the immune responses of juvenile grouper, Epinephelus malabaricus. C2MP‐Mg and C2MP‐Na were each supplemented at 20, 50, 80, 150, 250, and 400 mg kg?1 diet in the basal diet providing of 7, 18, 31, 51, 93, 145 mg ascorbic acid (AA) equivalent of C2MP‐Mg kg?1 diet and 4, 10, 17, 31, 47, 77 mg ascorbic acid (AA) equivalent of C2MP‐Na kg?1 diet, respectively. Basal diet without AA supplementation was included as control. Each diet was fed to triplicate groups of grouper (mean initial weight 3.20 ± 0.05 g). Fish fed diets supplemented with either C2MP‐Mg or C2MP‐Na had significantly (P < 0.05) greater weight gain (WG), feed efficiency and survival than those fed the unsupplemented control diet. Liver ascorbate concentrations in fish generally increased as dietary C2MP‐Mg or C2MP‐Na supplementation level increased. Haemolytic complement activity was higher in fish fed diets supplemented with 92 mg AA equivalent of C2MP‐Mg kg?1 or 10–17 mg AA equivalent of C2MP‐Na kg?1 than fish fed the unsupplemented control diet. Lysozyme activity was higher in fish fed ≥51 mg AA equivalent of C2MP‐Mg kg?1 or ≥47 mg AA equivalent of C2MP‐Na kg?1 than fish fed the unsupplemented control diet. Analysis by broken‐line regression of WG indicated that the adequate dietary vitamin C concentration from each vitamin C derivative in growing grouper is 17.9 mg AA equivalent of 2MP‐Mg kg?1 and 8.3 mg AA equivalent of C2MP‐Na kg?1, and it also indicated that C2MP‐Mg is about 46% as effective as C2MP‐Na in meeting the vitamin C requirement of grouper.  相似文献   

13.
Teleost fish lack the enzyme for endogenous synthesis of ascorbic acid (AA), an essential micronutrient for fish. The aim of this study was to examine the effect of higher levels of dietary vitamin C on growth, nutritional quality, and immunomodulation in the Indian major carp, rohu (Labeo rohita). Four groups of L. rohita were fed experimental diets containing either no vitamin C (control) or supplemented with vitamin C at 500 mg kg−1 (Exp-1), 1000 mg kg−1 (Exp-2), or 1500 mg kg−1 (Exp-3) for 60 days. Growth parameters (NWG, ADG, and SGR), serological parameters (TSP, TSA, TSG, and A:G), haematological parameters (TLC, TEC, Hct, MCV, and MCH), and different non-specific immunological parameters (PR, PI, respiratory burst activity, and bactericidal activity) were evaluated during the experimental trial. Fish fed a vitamin C-supplemented diet showed higher specific growth rate (SGR) up to 1000 mg kg−1 compared with control fish. Different haematological and serological parameters along with non-specific immune parameters were influenced by vitamin C supplementation. Among the non-specific immune parameters phagocytic activity (PR and PI) and respiratory burst activity (NBT cells) were significantly (P ≤ 0.05) enhanced by increasing doses of vitamin C supplementation. Higher levels of dietary vitamin C significantly (P ≤ 0.05) enhanced protection against Aeromonas hydrophila (AH1) infection compared with controls. Results from this study help to establish the beneficial effect of vitamin C on growth and immunmodulation in rohu (L. rohita).  相似文献   

14.
To determine dietary magnesium (Mg) requirements of juvenile grass carp, Ctenopharyngodon idella, magnesium sulphate was added to the basal diet at 0, 150, 300, 600, 1200, 2400 mg Mg kg−1 diet. Each diet was fed to three replicate groups of juvenile grass carp (initial weight: 7.69 ± 0.13 g) in a closed, recirculating rearing system for 76 days. No mortality or nutritional deficiency signs were observed except the growth depression in fish fed the Mg‐deficient diet. Growth performance and activities of serum superoxide dismutase (SOD), glutathione peroxidase (GPx) and lysozyme (LSZ) were highest (P <0.05) in fish fed the diet supplemented with 600 mg Mg kg−1. The serum malondialdehyde (MDA) content was higher (P <0.05) in fish fed the diets supplemented with 0 and 150 mg Mg kg−1 than that in fish fed the diets with ≥300 mg Mg kg−1. Mg concentrations both in whole‐body and vertebrae increased with the increase in dietary Mg level up to 300 mg kg−1, whereupon the response reached a plateau. Analysis by second‐order polynomial regression of weight gain, by broken‐line regression of vertebrae Mg concentration and by linear regression of whole‐body Mg retention of fish indicated that the adequate dietary Mg concentration for juvenile grass carp was 713.5, 627.7 and 469.8 mg kg−1 diet, respectively.  相似文献   

15.
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   

16.
The effect of feeding frequency (one, three, and continuous feeding), feed ration (0.2, 0.5, 0.8% of total fish biomass), and feeding per se on the oxygen consumption (OC, mg O2 kg−1 h−1) and ammonia excretion (AE, mg TAN kg−1 h−1) of juvenile tench (body weight 15–19 g) and variations in these parameters in daily cycles were examined. Fish metabolism was studied in a recirculating system (rearing tanks of 0.2 m3, water temperature 23 °C). It was found that oxygen consumption and ammonia excretion depended significantly on feed ration. An increase of feed ration from 0.2 to 0.8% of fish biomass caused an increase of OC and AE from 126.80 mg O2 kg−1 h−1 and 1.95 mg TAN kg−1 h−1 to 187.35 mg O2 kg−1 h−1 and 8.80 mg TAN kg−1 h−1 (p<0.05). There was no dependence between feeding frequency and the mean rate of oxygen consumption. However, the relationship between feeding frequency and ammonia excretion by juvenile tench was statistically significant (p<0.05). Feeding frequency significantly affected daily fluctuations of AE and OC. It was found that diurnal variations in metabolic rates were strictly related to tench feeding, and the daily variations of AE were significantly higher than OC.  相似文献   

17.
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   

18.
A study was conducted to determine the effects of dietary phospholipid (PL) levels in cobia (Rachycentron canadum) larvae with regard to growth, survival, plasma lipids and enzymes of lipid metabolism. Fish with an average weight of 0.4 g were fed diets containing four levels of PL (0, 20, 40 and 80 g kg−1dry matter: purity 97%) for 42 days. Final body weight (FBW), weight gain (WG) and survival ratio were highest in the 8% PL diet group and mortality was highest in PL-free diet group. We examined the activities of lipoprotein lipase (LPL) and hepatic lipase (HL) in liver, lecithin-cholesterolacyltransferase (LCAT) in plasma as well as plasma lipids and lipoprotein. LCAT activity showed a decrease of more than two-fold in PL-supplemented diet groups compared with the PL-free diet group. HL activity was highest in the 8% PL diet group and the other three groups showed no difference. LPL activity was significantly higher in the PL-supplemented diet groups than in the PL-free diet group. The dietary intervention significantly increased plasma phospholipids and total cholesterol (TC) levels, and the higher free cholesterol (FC) level contributed to the TC level. However, the fish fed PL exhibited a significantly decreased plasma triglyceride (TG) level. The lipoprotein fractions were also affected significantly by the PL. The PL-supplemented diet groups had significantly higher high-density lipoprotein (HDL) compared with the PL-free diet group, but showed a marked decrease in very low-density lipoprotein (VLDL). The results suggested that PL could modify plasma lipoprotein metabolism and lipid profile, and that the optimal dietary PL level may well exceed 80 g kg−1 for cobia larvae according to growth and survival.  相似文献   

19.
Epigallocatechin-3-gallate (EGCG), a very potent antioxidant derived from green tea, was compared with vitamin E in terms of its effects on antioxidant defense and immune response of rainbow trout, by means of a feeding trial of eight weeks. Two of the experimental diets were supplemented with EGCG at either 20 or 100 mg kg−1 diet (which contained only 30% of the intended levels) and the third was provided with 100 mg kg−1 vitamin E but not EGCG. The control diet was not supplemented with the test components. Observation of tissue levels indicated that the high amount of EGCG helped to increase the availability of the lipid-soluble antioxidant vitamin E. The lower levels of lipid hydroperoxide in the liver of fish fed the higher amount of EGCG suggested that it was an effective antioxidant. Considering the immune indices, EGCG and vitamin E at 100 mg (actual amounts 31.9 and 94.1 mg kg−1 diet, respectively) had identical capabilities in improving phagocytic activity and controlling hydrogen peroxide production by leucocytes. However, EGCG could possibly be more effective at enhancing serum lysozyme activity and the alternative complement activity. This work revealed the potential of EGCG as an antioxidant and an immunostimulant for rainbow trout, at least at the inclusion level of 32 mg kg−1 diet.  相似文献   

20.
Basal diet containing 0.5, 1.0, 1.5 and 2.0 g kg?1 mixture of inosine monophosphate (IMP), adenosine monophosphate (AMP), guanosine monophosphate (GMP), uridine monophosphate (UMP) and cytidine monophosphate (CMP) (1 : 1 : 1 : 1 : 1) (mixed‐NT; Experiment 1) and 1.5 g kg?1 from each nucleotides and mixed‐nucleotides (NT; Experiment 2) were fed to triplicate groups of grouper for 8 weeks. Basal diet without NT was used as control in both Experiments. In Experiment 1, fish fed the diet with 1.5 g mixed‐NT kg?1 had higher (P < 0.05) weight gain (WG) than the control group. The superoxide anion (O2?) production ratio was higher in fish fed diets with 1.0–1.5 g mixed‐NT kg?1 than the fish fed diets with ≤0.5 g mixed‐NT kg?1. In Experiment 2, fish fed diets with nucleotides had higher WG than the control group. The O2? production ratio was higher in fish fed the diet with 1.5 g AMP kg?1, followed by fish fed diets with 1.5 g UMP and mixed‐NT kg?1, and lowest in the control group. These results suggest that growth and immune responses were enhanced in grouper fed diet with 1.5 g mixed‐NT kg?1 diet. Diet with 1.5 g kg?1 of AMP seems to be more beneficial on the immune responses in fish than other nucleotides.  相似文献   

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