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1.
Invertebrate meals (e.g. polychaetes and insects) present novel and sustainable high‐quality nutrient sources for use in fish feed formulations. To test this innovative source, an eleven‐week feeding trial was conducted evaluating the effects of replacing the fishmeal (FM) component as an example of a superior protein source (FM CTRL) with ragworm meal (RW, Nereis virens) and/or silkworm pupae (SWP, Bombyx mori) in mirror carp (Cyprinus carpio) diets. Three experimental diets with partial replacement of FM (diets: RW + FM, SWP + FM and RW + SWP + FM) were formulated. All diets were formulated to be iso‐nitrogenous, iso‐lipidic and iso‐energetic. Growth performance and feed utilization indices were assessed, and the feeding trial concluded with the analysis of haematological parameters to provide an indication of carp physiological and health status. Mean weight gain was greatest in mirror carp fed RW + FM (60.83 fish?1 day?1; P < 0.05 vs. all other diets) followed by SWP + FM (40.62 g fish?1 day?1; P < 0.05 vs. all other diets). The least weight gain was achieved in fish fed FM + SWP + RW+ and FM CTRL (34.34 and 33.96 g fish?1 day?1, respectively; not significantly different from each other). Fish fed on RW + FM diet had significantly lower plasma ammonia concentrations than any other dietary groups (P = 0.04). Mirror carp fed on SWP + FM diet (111.52 units mL?1) were observed to have a marked enhancement in alternative complement activity than FM CTRL (79.21 units mL?1, P = 0.041). Both ragworm and silkworm pupae meal present attractive sustainable functional feed component in carp diets, with benefits on enhancing growth performance and specific physiological parameters.  相似文献   

2.
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   

3.
In experiment 1, juvenile sea urchins (n = 80, 0.088 ± 0.001 g wet weight and 5.72 ± 0.04 mm diameter) were held individually and fed ad libitum one of three semi‐purified formulated diets (n = 16 individuals treatment?1). In the diets, protein was held constant (310 g kg?1 dry, as fed) and carbohydrate level varied (190, 260, or 380 g kg?1 dry, as fed). Wet weights were measured every 2 weeks. Total wet weight gain was inversely proportional to dietary carbohydrate level and energy content of the respective diet. In experiment 2, sea urchins (5.60 ± 0.48 g wet weight, n = 40) fed 190 g kg?1 carbohydrate consumed significantly more dry feed than those fed 260 g kg?1, but not more than those fed 380 g kg?1 carbohydrate. Based on differential feed intake rates, sea urchins that consumed more feed also consumed higher levels of protein and had the highest weight gain. Consequently, protein content and/or protein: energy ratio may be important in determining feed utilization and growth among sea urchins in this study. The average digestible energy intake was approximately 70 kcal kg?1 body weight day?1, suggesting daily caloric intake of juvenile Lytechinus variegatus is lower than in shrimp and fish.  相似文献   

4.
An 11‐week feeding trial was conducted to evaluate the effect of dietary methionine on the growth, antioxidant status, innate immune response and disease resistance to Aeromonas hydrophila of juvenile yellow catfish. Six isonitrogenous and isolipidic practical diets were formulated to contain different graded methionine levels ranging from 6.1 to 16.4 g kg?1 of dry weight. The results indicated that growth performance and feed utilization were significantly influenced by the dietary methionine levels; fish fed the diet containing 6.1 g kg?1 methionine level had lower specific growth rate, percentage weight gain (PWG), feed efficiency and protein efficiency ratio than those fed the other diets (P < 0.05). Fish fed the diet containing 16.4 g kg?1 methionine level had lowest protein contents in whole body and muscle among all treatments. Triacylglycerols, cholesterol, aspartate aminotransferase, alanine aminotransferase and haemoglobin (Hb) in plasma or whole blood were significantly affected by dietary methionine levels. Fish fed the diet containing 6.1 g kg?1 methionine level had higher superoxide dismutase, glutathione peroxidase activities and malondialdehyde values than those fed other diets. Fish fed diets containing 9.7 and 11.8 g kg?1 methionine levels had higher lysozyme activity, total immune globulin, phagocytic activity and respiratory burst than those fed other diets. The lowest survival after A. hydrophila challenge was observed in fish fed a diet containing 6.1 g kg?1 methionine. Quadratic regression analysis of PWG against dietary methionine levels indicated that the optimal dietary methionine requirement for the maximum growth of juvenile yellow catfish was estimated to be 11.5 g kg?1 of the diet in the presence of 4.0 g kg?1 cystine (corresponding to 23.5 g kg?1 of dietary protein on a dry weight basis).  相似文献   

5.
A growth trial was conducted to examine the effect of dietary digestible energy (DE) content on methionine (Met) utilization and requirement in juvenile Nile tilapia (Oreochromis niloticus). Ten iso‐nitrogenous (288 g kg?1 protein) practical diets, with two DE levels (10.9 MJ kg?1; 12.4 MJ kg?1) and five methionine supplementation levels (0, 1, 2, 4 and 6 g kg?1), were hand‐fed twice daily to triplicate groups of Nile tilapia (initial body weight 8.95 ± 0.06 g) for 8 weeks. Weight gain (WG) and specific growth rate (SGR) increased significantly with increasing dietary methionine concentration at the same DE content (P < 0.001). At the same dietary methionine level, WG and SGR of fish fed high‐DE diets were significantly higher than that of fish fed low‐DE diets (P = 0.0001), although no interaction was found between dietary DE and methionine supplementation. Based on quadratic regression analysis between dietary methionine concentration and weight gain, optimal methionine requirement for maximum growth, expressed as g Met required kg?1 diet (low‐ versus high‐DE diets), increased as diet DE concentration increased (7.34 versus 9.90 g kg?1 diet, respectively; with cysteine 4.70 g kg?1 diet). The results indicated that diet DE content affects methionine utilization and requirement in juvenile Nile tilapia, fish fed high‐DE diets required more methionine for maximum growth.  相似文献   

6.
The aim of the present work was to obtain the lipid utilization of Octopus vulgaris supplying formulated semi‐moist diets with different contents in cod oil (reduced from water content): 0 g kg?1 (A0, 138 g kg?1 lipids DW; N = 4), 100 g kg?1 (A100, 286 g kg?1 lipids DW; N = 6) and 200 g kg?1 (A200, 388 g kg?1 lipids DW; N = 6). The rest of the ingredients were constant in the three diets: 200 g kg?1 gelatin, 100 g kg?1 egg yolk powder, 150 g kg?1 freeze‐dried Todarodes sagittatus and 50 g kg?1 freeze‐dried Sardinella aurita). Survival was 100% with the three diets. The highest absolute feeding (15.8 ± 1.2 g day?1), growth (9.6 ± 1.4 g day?1; 0.91% BW day?1) and feed efficiency rates (60.3%) were obtained with diet A0. This diet also showed greater retention of lipid and protein than A100 and A200. Protein digestibility was above 95% in all of the diets. Only diet A0 led to a high lipid digestibility coefficient (81.25%), which fell drastically to 12.3% in A200. It was notable the high polar lipid digestibility rates (83–89%) respect to neutral lipids (2–87%) in all diets. The best results were obtained with lipid feeding rates of around 1 g day?1 and a suitable lipid content on 130–140 g kg?1 DW in formulated diets for O. vulgaris.  相似文献   

7.
A total of 630 juvenile Chinese sucker, with an average initial weight of 1.72 ± 0.05 g, were fed seven diets for 56 days to study the effect of dietary methionine levels on growth, feed utilization, body composition and haematological parameters on juvenile Chinese sucker. Diet 1 using fish meal as the sole protein source and diets 2–7 using fish meal and fermented soybean meal as intact protein sources supplemented with crystalline amino acids contained six levels of l ‐methionine ranging from 6.4 to 18.9 g kg?1 of dry diet at a constant dietary cystine level of 3.7 g kg?1. Each diet was randomly assigned to three aquaria. Results indicated that the highest weight gain, specific growth rate (SGR), feed efficiency ratio, protein efficiency ratio and protein productive value occurred at 13.9 g methionine kg?1 diet among the methionine supplemented dietary groups, beyond which they showed declining tendency. The whole body and muscle protein contents of juvenile Chinese sucker were positively correlated with dietary methionine level, while muscle lipid content was negatively correlated with it. The total essential amino acids content of muscle was increased significantly with increasing dietary methionine level from 6.4 to 13.9 g kg?1 (P < 0.05). Apparent digestibility coefficients of dietary protein were significantly affected by dietary treatments. Serum protein, cholesterol and triacylglycerol increased with increasing dietary methionine levels, but showed a relatively lower value for fish fed the 18.9 g methionine kg?1 diet. Quadratic regression analysis of SGR against dietary methionine level indicated that optimal dietary methionine requirement for juvenile Chinese sucker was 14.1 g kg?1 of the diet in the presence of 3.7 g kg?1 cystine (corresponding to 32.0 g kg?1 of dietary protein on a dry‐weight basis).  相似文献   

8.
A 14 weeks growth trial was performed to estimate the protein requirement for growth and maintenance of zebra sea bream (Diplodus cervinus) juveniles. For that purpose, nine isolipidic diets were formulated to contain increasing protein levels (from 50 to 550 g kg?1) at the expense of carbohydrate. Each diet was assigned to duplicate groups of 20 fish, with an average body weight of 7.7 g. Feed efficiency improved with dietary protein up to 400 g kg?1, no further differences being noticed at higher protein levels. Fish fed the 50 g kg?1 protein diet lost weight during the trial. In the other groups, weight gain improved as dietary protein increased up to 350–400 g kg?1. Fish fed diets with 250 g kg?1 protein or lower had lower whole‐body protein content than the other groups. A curvilinear‐plateau model was used to adjust weight gain and protein gain (g kg ABW?1 day?1) to dietary protein levels. Based on that model, the optimum dietary protein requirement for maximum weight gain was estimated to be 437.6 g kg?1 and for maximum protein gain 461.9 g kg?1, corresponding to a protein intake of 7.63 g kg ABW?1 day?1. Protein requirement for maintenance was estimated to be 1.01 g kg ABW?1 day?1.  相似文献   

9.
A 10‐week feeding trial with four dietary protein levels (400, 450, 500 and 550 g kg?1 crude protein) and two dietary lipid levels (80 and 160 g kg?1 crude lipid) was conducted to assess optimum dietary protein and lipid levels for the growth, feed utilization and body composition of juvenile Manchurian trout (initial weight 11.80 ± 0.15 g). Fish were fed twice daily (08:30 and 16:30 h) to apparent satiation. The results showed that fish fed the diet with 500 g kg?1 protein and 80 g kg?1 lipid had the highest growth and feed efficiency. However, fish fed the diet with 450 g kg?1 protein and 160 g kg?1 lipid showed comparable growth to that of the fish fed diet 5 (500/80) and had higher protein efficiency ratio (PER), nitrogen retention (NR) and energy retention (ER) than other groups (P < 0.05). Growth, PER, NR and ER of fish fed the 160 g kg?1 lipid diet was significantly higher (P < 0.05) than that of fish fed the 80 g kg?1 lipid diet at 400 and 450 g kg?1 protein diet, whereas these values showed an opposite trend at 500 and 550 g kg?1 protein diet, and the lowest PER, NR and ER was found by fish fed the 400 g kg?1 protein diet with 80 g kg?1 lipid. Fish fed diets with 400 g kg?1 protein had lower feed intake (FI) than that of other groups. Feed intake of fish fed 80 g kg?1 lipid level was significantly lower than that of fish fed 160 g kg?1 lipid diet at 400 g kg?1 protein (P < 0.05), while no significant differences were observed at 450, 500 and 550 g kg?1 protein‐based diets. Contrary to moisture content, lipid content of whole body and muscle increased significantly (P < 0.05) with increasing lipid levels. The results of this study indicated that the diet containing 450 g kg?1 protein and 160 g kg?1 lipid, with a P/E ratio of 23.68 g protein MJ?1 would be suitable for better growth and feed utilization of juvenile Manchurian trout under the experimental conditions and design level used in this study.  相似文献   

10.
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 (P > 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   

11.
The aim of this experiment was to determine the effects of dietary inclusion with mannan oligosaccharide (Bio‐Mos, Alltech, Nicholasville, KY, USA) on growth, survival, physiological and immunological conditions and gut morphology of the black tiger prawn (Penaeus monodon). Five diets supplemented with MOS at 0 g kg?1 (control diet), 1, 2, 4 and 8 g kg?1 were fed to the prawn juveniles (0.4 ± 0.06 g, total weight) for the duration of 63 days. Growth was the highest (P < 0.05) when the prawns were fed the 1 g kg?1 MOS included diet. Wet tail muscle index (Tw/B), dry tail muscle index (Td/B) and tail muscle protein (Tmp) were higher (P < 0.05) in the prawns fed MOS included diets MOS compared with the prawns fed the control diet. Total haemocyte counts (THCs) of the prawns fed MOS included diets were higher (P < 0.05) than THCs of the prawns fed the control diet. Epithelium layer and epidermal cell density of the gut of the prawns fed 1 g kg?1 and 2 g kg?1 MOS diets were better than the prawns fed the control and other MOS diets. The results imply a positive effect of dietary supplementation of 1–2 g kg?1 MOS in the culture of black tiger prawns.  相似文献   

12.
A 12‐week feeding trial was conducted to estimate the dietary copper requirement of fingerling Channa punctatus. Six casein?gelatin‐based test diets (450 g kg?1 crude protein; 18.81 kJ g?1 gross energy) with graded levels of copper as copper sulphate (3.7, 4.7, 5.7, 6.7, 7.7 and 8.7 mg copper equivalent kg?1 diet) were formulated and fed to triplicate groups of fish (7.25 ± 0.81 cm; 5.21 ± 0.27 g) near to satiation. Fish fed diet with 6.7 mg kg?1 copper had highest absolute weight gain (AWG; 51.63 g fish?1), protein efficiency ratio (PER; 1.42 g fish?1), protein gain (PG; 8.34 g fish?1), haemoglobin (Hb; 9.68 g dL?1), haematocrit (Hct; 31.18%) and RBCs (3.24 × 106 × mm?3). Feed conversion ratio (FCR) was found to be best (1.57) at above level of dietary copper. Whole body copper concentration was found to increase with the increasing levels of dietary copper. Hepatic thiobarbituric acid‐reactive substances concentration was found to decrease with increasing dietary concentrations of copper up to 6.7 mg kg?1 beyond which a reverse trend in this parameter was noted. Broken‐line regression analysis of AWG, FCR and PG concentrations against varying levels of dietary copper yielded the requirement in the range of 6.66–6.78 mg kg?1. Data generated during this study would be useful in formulating copper‐balanced commercial feeds for the intensive culture of this fish.  相似文献   

13.
We studied the feeding and growth rates, feed efficiency and nutritional composition of subadult octopuses (689 ± 77 g) fed low‐lipid diets with two different protein/energy ratios (P/E): Medium P/E diet (30.5 g protein MJ?1, 662 g kg?1 protein dry weight (dw)) or High P/E diet (36.8 g protein MJ?1, 843 g kg?1 protein dw). Survival was 100% for the Medium P/E and 87.5% for the High P/E diet. The specific feeding rates were 1.91% and 1.67% body weight day?1 for the Medium P/E and High P/E diet, respectively (P < 0.05). The specific growth rates (0.92% and 1.25% body weight day?1), feed efficiency indices (47.3% and 72.7%), productive protein value (23.9% and 29.1%) and digestive gland index (5.6% and 6.4%) were significantly better in animals fed the High P/E than the Medium P/E diet (P < 0.05). The proximate composition of the digestive gland was similar for both diets, but the total lipid content of carcass was higher in animals fed the Medium P/E diet (P < 0.05). Our results suggest that the protein content of the feed could be a factor regulating feeding rates in octopus.  相似文献   

14.
A 12‐week feeding trial was conducted in eighteen 70 L indoor polyvinyl circular troughs provided with a water flow‐through system (1–1.5 L min?1) at 28 ± 1 °C to evaluate the dietary tryptophan requirement of fingerling Catla catla (3.45 ± 0.24 cm; 0.60 ± 0.13 g). Six casein‐gelatin‐based amino acid test diets (330 g kg?1 crude protein; 13.6 kJ g?1 digestible energy) containing graded levels of L‐tryptophan (1.0, 1.4, 1.9, 2.3, 2.8, 3.4 g kg?1 dry diet) were fed to triplicate groups of fish near to satiation at 08:00, 12:30 and 17:30 h. Absolute weight gain, feed conversion ratio, protein gain, RNA/DNA ratio, hepatosomatic index, viscerosomatic index, condition factor and haematological indices improved with the increasing levels of tryptophan from 1.0 to 2.3 g kg?1 of dry diet. Significantly higher carcass protein was obtained at 2.3 g tryptophan per kilogram of the dry diet. Exponential analysis of absolute weight gain, feed conversion ratio, protein gain and RNA/DNA ratio against dietary tryptophan levels at 95% maximum and minimum responses displayed the tryptophan requirement at 2.5, 2.3, 2.5 and 2.1 g kg?1 dry diet, respectively. Inclusion of dietary tryptophan in the range of 2.1–2.5 g kg?1 dry diet, equivalent to 6.4–7.6 g kg?1 dietary protein, is recommended in formulating tryptophan‐balanced feed for the culture of this fish species.  相似文献   

15.
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   

16.
A study was conducted to estimate the optimum requirement of dietary available phosphorus for GIFT strain of Nile tilapia Oreochromis niloticus. Six purified diets were formulated to contain graded levels (0 (control diet), 2.9, 4.8, 7.6, 9.1 and 10.9 g kg?1 diet) of available phosphorus. Each diet was fed to triplicate groups of 12 fish with initial average weight (46.03 ± 2.14) g for 8 weeks. The results showed that fish fed the three lowest phosphorus diets (0, 2.9 and 4.8 g kg?1) had significantly lower weight gain rate, specific growth rate (SGR) and feed efficiency than those fed the other diets (P < 0.05). The survival rate of fish fed the control diet was significantly lower than that of the fish fed the other diets (P < 0.05). Whole body viscerosomatic index and crude lipid content decreased significantly with increasing dietary available phosphorus levels (P < 0.05), while the contents of crude ash, calcium, phosphorus in the whole body and vertebrae showed the opposite trend (P < 0.05). The blood chemistry analysis showed that dietary available phosphorus had significant effects on serum phosphorus concentration, enzyme activities of alkaline phosphatase and parathyroid hormone level. Quadratic curve analysis based on SGR indicated that the minimum dietary requirement of available phosphorus for maintaining optimal growth of tilapia was 8.6 g kg?1.  相似文献   

17.
Present experiment was conducted to determine the effect of different feeds with varying protein levels on the growth, survival and reproductive performance of zebrafish, Danio rerio. The control diet (T1) was wild‐collected zooplankton from local fish ponds, while test diets with 350 g kg?1 protein (T2), 400 g kg?1 protein (T3) and 450 g kg?1 protein (T4) were formulated and fed to fish for a period of 210 days. The significantly (P < 0.05) highest mean weight gain and specific growth rate were observed in T1, which were similar with T3 and T4. The significantly (P < 0.05) highest number of egg production per female and relative fecundity were found in T1, followed by T4 and T3 while T2 produced lowest number of eggs. No significant (P > 0.05) differences were observed in brood survival rate, fertilization and hatching rate among the dietary treatments. The highest (P < 0.05) fry survival rate was recorded in T1, followed by T3 and T4. Thus, it is suggested that control diet i.e. mixed zooplankton exhibited better growth, reproductive performance and fry survival rate. However, diet containing 400 g kg?1 crude protein also gave comparable results in terms of growth, survival and reproductive performance of zebrafish.  相似文献   

18.
Four semi‐moist formulated feeds were supplied to Octopus vulgaris subadults (664 ± 70 g; 18.4 ± 0.7°C) in two different experiments. In the experiment #1, two diets were prepared with a new mixture of binders (gelatine 150 g kg?1, starch 100 g kg?1 and gum 50 g kg?1). The GEL15‐Squid and GEL15‐Hake feeds included 100 g kg?1 freeze‐dried squid (Todarodes sagittatus) or hake (Merluccius sp.) respectively. Both feeds showed low water disintegration rates at 24 h (13.6–15.0% dry weight). The specific feeding rate was higher in animals fed GEL15‐Hake (2.7%BW day?1), but the growth and feed efficiency were significantly better in animals fed GEL15‐Squid (1.4%BW day?1 and 61.2% respectively; P < 0.05). The proximate composition of the digestive gland, carcass and whole animals was similar. In the experiment #2, the GEL15‐Squid amino acid profile was improved by replacing 50 g kg?1 gelatine by 50 g kg?1 freeze‐dried squid (GEL10‐Squid) or freeze‐dried fish (GEL10‐Fish). These feeds showed higher water disintegration rates (31.7–36.3% dry weight). The feeding rates (2.2–2.3%BW day?1), growth (1.5%BW day?1) and feed efficiency were similar for both diets. Total lipids were higher in the digestive gland and whole animals fed GEL10‐Fish diet (P < 0.05). Future effort could be directed towards alternative binders that allow improve amino acid balance with a minimum gelatine content or even supplementation trials including essential amino acids.  相似文献   

19.
The effects of dietary phosphorus (P) on growth, body composition and immunity of young taimen (Hucho taimen) were studied. Six purified diets contained graded levels (2.3‐control, 4.0, 5.6, 7.5, 9.1 and 10.8 g kg?1 diet) of available P. Each diet was fed to triplicate groups of 30 fish with an initial average weight (55.31 ± 0.38) g for 84 days. The weight gain, specific growth rate and feed conversion ratio were improved by dietary available P up to 4.35 g kg?1 (P < 0.05) and then levelled off. Hepatosomatic index and body crude lipid content decreased significantly with increasing P levels, while ash contents and P concentrations in the whole body and vertebrae increased by dietary available P up to 4.36 and 4.44 g kg?1 and then levelled off respectively (P < 0.05). Liver superoxide dismutase and glutathione peroxidase and plasma alkaline phosphatase activities in the treatment groups were significantly higher compared with the control group (P < 0.05). Plasma IgM contents increased linearly with increasing dietary P from 4.0 to 9.1 g kg?1 group and then decreased. Dietary P supplementation reduced plasma triglyceride, malondialdehyde and liver malondialdehyde contents. There were no significant effects on plasma total protein, albumin, globulin, glucose, aspartate aminotransferase and alanine aminotransferase, catalase, lysozyme and liver catalase compared with the control group (P > 0.05). Broken line regression analysis indicated that dietary available P requirement was 4.34 and 4.35 g kg?1, based on weight gain and P concentration in the whole body respectively.  相似文献   

20.
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   

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