首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 755 毫秒
1.
The study was conducted in Cam Ranh, Vietnam, in 1000‐L tanks supplied with recirculated and biofiltered saltwater (33‰ and 28.4 °C) to evaluate the potential use of lizard fish (Saurida undosquamis) or blue crab (Portunus pelagicus) acid silage protein for juvenile cobia (23–25 g). Six isoenergetic test moist diets (4915–5125 kcal kg?1), using either raw fish diet, fish silage diet (FSD), raw crab diet, crab silage diet (CSD), mixed raw fish/raw crab diet or mixed fish/crab silage diet (MSD), as part of the protein sources in the steam‐cooked diets, were fed to satiety to triplicate groups of 20 fish each for a 6‐week growth trial. Y2O3 was added as an inert indicator to determine the apparent digestibility coefficients (ADC) for macro nutrients and gross energy. Weight gain (185–286%) and specific daily growth rate (2.5–3.2% per day) were significantly higher in cobia fed the raw‐based diets and FSD than in fish fed CSD and MSD (34–90 and 0.7–1.5% per day). Feed conversion ratios (FCR) were significantly higher in the groups fed CSD and MSD diets (2.1–6.5) than the groups fed the other diets (1.0–1.2), resulting in significantly lower protein productive values (0.1–0.2) in the groups fed CSD and MSD than in the other groups (0.3–0.4). The FCR results were confirmed by significantly lower ADC values in fish fed CSD and MSD than those in fish fed the other diets. We thus conclude that the present raw‐based diets were better utilized by juvenile cobia than silage‐based diets, particularly the diet made from crab silage.  相似文献   

2.
Camelina meal (Camelina sativa) (CM) is a potential protein source for aquaculture feeds, on account of its crude protein level (380 g kg?1) and inclusion of most indispensable amino acids. Two experiments were conducted with rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). Rainbow trout (44.9 g fish?1) were fed diets with CM at 0 g kg?1 (0% CM), 70 g kg?1 (7% CM), 140 g kg?1 (14% CM) or 210 g kg?1 (21% CM) for 12 weeks at 14 °C in freshwater, and salmon (241.8 g fish?1) were fed diets with CM at 0 g kg?1 (0% CM), 80 g kg?1 (8% CM), 160 g kg?1 (16% CM) or 240 g kg?1 (24% CM) for 16 weeks at 14 °C in sea water. Growth, lipid and amino acid tissue compositions were compared between species. Trout could tolerate up to 14% CM diets without affecting the growth compared to the control, while salmon fed ≥8% CM gained less weight than the control (P = 0.008). The feed conversion ratio in trout fed 21% CM was higher than the control (P = 0.002), and feed intake in salmon fed ≥8% CM was lower than the control (P = 0.006). Trout fatty acid and amino acid composition showed minimal differences between CM‐fed and control‐fed fish, while salmon showed significant alterations after feeding CM diets. Multivariate analyses emphasized differences in tissue composition between species fed CM diets.  相似文献   

3.
《Aquaculture Research》2017,48(4):1759-1766
A shrimp protein hydrolysate (SPH) containing 894.2 g kg−1 crude protein (CP) and 54.3 g kg−1 total lipids was tested as a partial replacement for fish meal (FM) in diets of juvenile cobia. The effects of increasing dietary levels of SPH on the survival, weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR), nitrogen retention efficiency (NRE) and daily feed intake (DFI) of cobia with initial body weight of 11.9 g were evaluated. Four isoproteic (from 431.1 to 439.7 g kg−1) and isoenergetic (20 825–21 347 MJ kg−1) diets were formulated to contain 0 (Control), 120, 240 or 360 g kg−1 of dietary CP derived from SPH. Survival, WG, SGR, FCR, NRE and DFI ranged from 90 to 100%, 40.2–56.5 g, 4.7–6.1% day−1, 1.04–1.54, 26.3–44.0% and 4.7–6.0% fish−1 day−1 respectively. Survival and DFI were not affected by the dietary treatments. On the other hand, fish fed the control diet and the one containing 120 g kg−1 SPH had higher WG, SGR and FCR. Nitrogen retention efficiency was significantly higher for fish fed diets 0 and 120. It is concluded that up to 120 g kg−1 of SPH in cobia diets can be used with no significant effects on feed utilization and fish performance.  相似文献   

4.
Economical, nutritious diets for hybrid striped bass (HSTB) are required for the continued expansion and sustainability of this industry. Turkey meal (TM) is a by‐product of the US turkey industry and is a potentially‐valuable local, alternative protein source for use in aquaculture diets because of its excellent nutritional composition and quality. TM may substitute for more expensive fish meal (FM)‐based diets; however, there are no published data with regard to using this ingredient in sunshine bass diets. Therefore, a 16‐week feeding trial was conducted with juvenile (36 g) sunshine bass (Morone chrysops × Morone saxatilis) to evaluate growth, feed conversion and body composition when fed diets with decreasing levels of FM (300, 200, 100 and 0 g kg?1) and increasing levels of turkey meal (0, 97, 175 and 264 g kg?1). Four practical diets were formulated to contain 400 g kg?1 protein and similar energy levels. Twenty fish were stocked into each of the 12, 1200‐L circular tanks and were fed twice daily ad libitum. At the conclusion of the feeding trial, there were no significant (P > 0.05) differences in final mean weight, percentage weight gain, specific growth rate and feed conversion ratio among treatments, which averaged 363.7 g, 904.3%, 2.02% day?1 and 1.73, respectively. Percentage survival of fish fed diet 4 (0 g kg?1 FM and 264 g kg?1 TM) was significantly (P > 0.05) lower (survival = 88.3%) than fish fed diet 3 (100 g kg?1 FM and 175 g kg?1 TM; survival = 95%), but not different from fish fed diet 1 (survival = 92.5%) and fish fed diet 2 (survival = 93.3%). Fillet weight and amount of abdominal fat were not significantly different among all treatments and averaged 258 and 58 g kg?1, respectively. Fish fed diet 1 (300 g kg?1 FM, 0 g kg?1 TM) and diet 2 (200 g kg?1 FM and 970 g kg?1 TM) had a significantly (P < 0.05) lower hepatosomatic index (2.83 and 3.01, respectively) than fish fed diet 4 (3.33), but not different (P > 0.05) compared to fish fed diet 3 (3.14). Lipid in the fillet of fish fed diet 2 (197 g kg?1) was significantly (P < 0.05) higher than fish fed all other diets; and the percentage lipid in the fillet of fish fed diet 1 (126 g kg?1) was significantly lower than fish fed diets 2 and 4, but not different (P >0.05) compared to fish fed diet 3. Fillet moisture, protein and ash were similar among fish fed all diets and averaged 748, 798 g kg?1 and 51.0 g kg?1 (dry‐matter basis), respectively. The amino acid composition of fillets was similar among all treatments with a few slight significant differences. Results from the present study indicate that tank‐grown sunshine bass can be fed a diet containing 264 g kg?1 TM with 0 g kg?1 FM, compared to diets containing up to 300 g kg?1 FM, without adverse effects on weight gain, growth rate, feed conversion and body composition. Further research should be conducted using lower‐protein diets to determine minimum protein level for tank‐grown sunshine bass.  相似文献   

5.
The dietary lysine requirement of juvenile gilthead seabream was determined by the growth response of duplicate groups of fish (3.5 g initial weight) fed on six isonitrogenous (427 g kg?1) and isolipidic (135 g kg?1) diets containing graded levels of crystalline l ‐lysine HCl, with dietary lysine content ranging from 36.3 to 79.7 g kg?1 of protein. The final indispensable amino acid profile of the diets except for lysine was formulated so as to resemble that of wild seabream whole body. Except for the reduced growth performance of fish groups fed the lysine‐deficient diets no other deficiency signs were apparent. Survival observed throughout the feeding period of 6 weeks was excellent. Weight gain (in %), specific growth rate, feed efficiency and daily protein deposition (DPD) were significantly improved in response to the increasing levels of dietary lysine up to 52.7 g kg?1 of protein and remained nearly constant thereafter. Whole‐body protein content followed a similar pattern as growth parameters in relation to dietary lysine level. Non‐linear regression analysis of DPD against dietary lysine level using the four‐parameter saturation kinetic model indicated a lysine requirement of 50.4 g kg?1 of protein for this species to support growth.  相似文献   

6.
This experiment was conducted to evaluate the effect of different levels of dietary phospholipid (PL) on growth, survival and nutrient composition of 25 days posthatch cobia Rachycentron canadum (0.4 g initial wet weight). For 42 days, fish were fed fish meal and protein hydrolysate based diets containing four PL levels (0, 20, 40 and 80 g kg?1dry matter: purity 97%) and phosphatidylcholine purity was 60%. All diets were isonitrogenous and isolipidic by regulating the fish oil and maize oil levels. Weight gain (2601–10892%), specific growth ratio (7.82–11.18) and survival (49–100) were significantly affected by dietary PL. Intraperitoneal fat ratio (0.19–0.74) and hepatosomatic index (2.67–3.08) increased with dietary PL level. The effect of dietary PL levels on the chemical composition of tissues was significant only for whole body and liver. The contents of plasma total cholesterol (2.47–3.77 mmol L?1) and PL (1.03–2.97 mmol L?1) increased with an increase in dietary PL. In conclusion, in our study survival and growth continued to increase even at the highest PL levels used (80 g kg?1); therefore optimal dietary PL levels may well exceed 80 g kg?1 for early juvenile cobia requirement. It also indicated from the experiment that PL could affect lipid deposition and resulted in a higher lipid level in fish tissue.  相似文献   

7.
A net pen experiment was carried out to examine the effect of dietary protein level on the potential of land animal protein ingredients as fish meal substitutes in practical diets for cuneate drum Nibea miichthioides. Two isocaloric basal (control) diets were formulated to contain 400 g kg?1 herring meal but two different digestible protein (DP) levels (400 versus 350 g kg?1). At each DP level, dietary fish meal level was reduced from 400 to 280, 200, 80 and 0 g kg?1 by incorporating a blend that comprised of 600 g kg?1 poultry by‐products meal (PBM), 200 g kg?1 meat and bone meal (MBM), 100 g kg?1 feather meal (FEM) and 100 g kg?1 blood meal (BLM). Cuneate drum fingerling (initial weight 42 g fish?1) were fed the test diets for 8 weeks. Fish fed the test diets exhibited similar feed intake. Final body weight, feed conversion ratio and nitrogen retention efficiency was not significantly different between fish fed the basal diets containing 350 and 400 g kg?1 DP. Weight gain decreased linearly with the reduction of dietary fish meal level at the 350 g kg?1 DP level, but did not decrease with the reduction of dietary fish meal level at the 400 g kg?1 DP level. Results of the present study suggest that fish meal in cuneate drum diets can be completely replaced with the blend of PBM, MBM, FEM and BLM at the 400 g kg?1 DP level, based on a mechanism that excessive dietary protein compensate lower contents of bio‐available essential amino acid in the land animal protein ingredients relative to fish meal.  相似文献   

8.
Two successive experiments were conducted in order to assess plasma free amino acid (FAA) profiles as a method for evaluating protein quality of fish feeds for Atlantic salmon, Salmo salar (L.). In experiment 1, the importance of meal size and inter‐fish variation was assessed by using dorsal aorta cannulated fish and diets that contained different sources of fishmeal (menhaden versus herring) which in the case of herring, had been dried at either 70 or 100 °C. In experiment 2, an attempt was made to mimic a production situation by comparing the FAA profiles in salmon fed diets containing two commercially available fishmeals that had been produced in accordance with industrial standards (Norse‐LT94® and NorSeaMink®; Norsildmel AL, Fyllingsdalen, Norway). FAA profiles in plasma 6 h after feeding were compared with feed true protein digestibility as determined in mink. Cannulated fish, held in individual tanks, were hand‐fed twice daily to pellet rejection (satiety) and daily records of the actual rations consumed were maintained. A total of 24 different amino acids and other amino‐containing compounds were detected using high‐pressure liquid chromatography. Morning and evening meal size showed significant correlations. Meal size had a significant effect on blood levels of the majority of essential free amino acids (EAA) as well as the total sum of FAA (TFAA). In experiment 1, a marked inter‐individual effect was found, possibly because of incipient sexual maturation. FAA profiles were therefore corrected for meal size by linear regression while repeated sampling via the permanently implanted cannula allowed paired comparisons of the different test diets, minimizing inter‐individual variation. Significant differences in plasma FAA profile, EAA and TFAA were detected between fish fed all diets in both experiments. The preceding parameters for fish ingesting each feed were directly related to their respective mink protein digestibility in experiment 1, but not in experiment 2. Our results show that dietary protein quality can be differentiated by the aforementioned protocol, and by using fish with a low metabolic rate feed qualities could be ranked correctly as in experiment 1.  相似文献   

9.
Three experiments were conducted that were designed to evaluate our ability to predict essential amino acid (EAA) needs of hybrid striped bass using the quantified lysine requirement and whole‐body amino acid concentrations. In the first experiment, six diets containing various amino acid profiles were fed to triplicate groups of fish initially weighing 7.7 g per fish. At the end of the 8‐week experiment, no significant differences were detected in growth rates or feed efficiencies (FE) between fish fed a practical diet containing 510 g kg?1 herring fish meal (FM) and fish fed a purified diet containing the amino acid profile of herring fish meal (CAA‐FM). Growth responses of fish fed purified diets containing 100 (HSB), 110 (HSB110), 120 (HSB120) or 140 g 100 g?1 (HSB140) of the amino acid profile of hybrid striped bass whole‐bodies were significantly lower than those of fish fed diet FM. In the second experiment, triplicate groups of fish (5.6 g per fish) were fed diets containing various energy : protein (E : P) ratios (34.8, 41.2, 47.5 and 53.9 kJ g?1 protein) and one of two amino acid profiles (CAA‐FM and HSB120) in a 4 × 2 factorial design. Carbohydrate concentration was varied to achieve the desired energy concentrations. At the end of the 8‐week experiment, weight gain and FE were significantly higher in fish fed diets formulated to simulate the amino acid profile of herring fish meal (CAA‐FM) compared with fish fed diets formulated to contain 120 g 100 g?1 of the amino acid profile of hybrid striped bass whole‐bodies (HSB120). Weight gain, FE and survival data indicated the optimum dietary E : P was 41.2 kJ g?1 protein. Dietary treatments in the final experiment included three amino acid profiles and four levels of lipid in a 3 × 4 incomplete factorial design. Dietary amino acid treatments included the amino acid profile of herring fish meal (CAA‐FM) or 120 g 100 g?1 of the predicted EAA requirement profile for hybrid striped bass (HSB120). The amino acid profile of the remaining dietary treatment (PRED+) was similar to that of the HSB120 treatment, but contained additional threonine, isoleucine and tryptophan. Diets CAA‐FM and HSB120 contained either 90, 130, 170 or 210 g kg?1 lipid, whereas diet PRED+ contained 130 g kg?1 lipid. Dietary treatments were fed for 10 weeks to triplicate groups of fish initially weighing 81.0 g per fish. Weight gain and FE were not significantly affected by dietary amino acid profile. Feed efficiency was significantly reduced in fish fed diets containing 210 g kg?1 lipid compared with fish fed diets containing 90–170 g kg?1 lipid. Intraperitoneal fat (IPF) ratio and hepatosomatic index (HSI) values generally increased as dietary lipid concentrations increased. Total liver lipid concentrations were significantly reduced in fish fed diets containing 210 g kg?1 lipid compared with those of fish fed 90–130 g kg?1 lipid. Results of this study indicate an appropriate dietary amino acid profile can be predicted for hybrid striped bass using the quantified lysine requirement and whole‐body amino acid concentrations. Further, the optimum E : P appears to be 40 kJ g?1 protein.  相似文献   

10.
This study was conducted to investigate the influence of dietary lipid source and n‐3 highly unsaturated fatty acids (n‐3 HUFA) level on growth, body composition and blood chemistry of juvenile fat cod. Triplicate groups of fish (13.2 ± 0.54 g) were fed the diets containing different n‐3 HUFA levels (0–30 g kg?1) adjusted by either lauric acid or different proportions of corn oil, linseed oil and squid liver oil at 100 g kg?1 of total lipid level. Survival was not affected by dietary fatty acids composition. Weight gain, feed efficiency and protein efficiency ratio (PER) of fish fed the diets containing squid liver oil were significantly (P < 0.05) higher than those fed the diets containing lauric acid, corn oil or linseed oil as the sole lipid source. Weight gain, feed efficiency and PER of fish increased with increasing dietary n‐3 HUFA level up to 12–16 g kg?1, but the values decreased in fish fed the diet containing 30 g kg?1 n‐3 HUFA. The result of second‐order polynomial regression showed that the maximum weight gain and feed efficiency could be attained at 17 g kg?1 n‐3 HUFA. Plasma protein, glucose and cholesterol contents were not affected by dietary fatty acids composition. However, plasma triglyceride content in fish fed the diet containing lauric acid as the sole lipid source was significantly (P < 0.05) lower than that of fish fed the other diets. Lipid content of fish fed the diets containing each of lauric acid or corn oil was lower than that of fish fed the diets containing linseed oil or squid liver oil only. Fatty acid composition of polar and neutral lipid fractions in the whole body of fat cod fed the diets containing various levels of n‐3 HUFA were reflected by dietary fatty acids compositions. The contents of n‐3 HUFA in polar and neutral lipids of fish increased with an increase in dietary n‐3 HUFA level. These results indicate that dietary n‐3 HUFA are essential and the diet containing 12–17 g kg?1 n‐3 HUFA is optimal for growth and efficient feed utilization of juvenile fat cod, however, excessive n‐3 HUFA supplement may impair the growth of fish.  相似文献   

11.
  相似文献   

12.
The present work was designed to study whether changes in dietary protein quality by means of partial inclusion of fish protein hydrolysate (FPH) would alter fish growth, feed utilization, protein retention and metabolism and fish health in general. FPH was produced after hydrolysing whole minced herring using the industrial enzyme Alcalase®. The dietary protein source, low‐temperature‐dried (LT) fishmeal nitrogen was exchanged with FPH nitrogen at six levels of inclusion ranging from 0 to 300 g kg?1. The experimental diets were fed to post‐smolt (1+) Atlantic salmon (Salmo salar), with mean initial weight of 174 g for a period of 68 days. All diets were iso‐nitrogenous, iso‐energetic and contained the same amount of amino acids. Fish fed medium inclusion of FPH (180–240 g kg?1) showed a tendency to have higher feed intake than fish fed lower and higher levels of FPH inclusions. Significant higher individual specific growth rates were present in fish fed diets with 180 and 240 g kg?1 FPH when compared with those fed 300 g kg?1. Feed conversion ratio increased significantly (R2 = 0.61) and protein efficiency ratio decreased significantly (R2 = 0.59) in fish fed increased levels of FPH. Further, apparent digestibility of crude protein and the amino acids arginine, lysine, methionine and phenylalanine increased significantly with increased dietary inclusion of FPH. Plasma free amino acids, ammonium and urea indicated that FPH amino acids was absorbed earlier and nonsynchronously, and may thus be more prone to be catabolized than in those fish fed the less solubilized protein. FPH inclusion did not have an impact on fish health, as evaluated by haematology and clinical parameters.  相似文献   

13.
A 10‐week feeding trial was conducted to determine the optimal requirement of cobia (Rachycentron canadum Linneaus) for dietary ascorbic acid (AA). Graded levels of L‐ascorbyl‐2‐polyphosphate (LAPP) were supplemented in basal diet to formulate six semi‐purified diets containing 2.70 (the control diet), 8.47, 28.3, 80.6, 241 and 733 mg AA equivalent kg?1 diet, respectively. Each diet was randomly fed to triplicate groups of fish in flow‐through plastic tanks (300 L), and each tank was stocked with 25 fish with average initial weight of 4.59 ± 0.36 g. Observed deficiency signs included poor growth, higher mortality and lower feeding rate (FR) in the fish of the control group. Fish fed the control diet had significantly lower weight gain (WG), lower feed efficiency ratio (FER) and lower tissue AA concentrations in fish liver and muscle. With the increase of dietary AA, the survival, WG, FER, hepatic and muscular AA concentrations of cobia significantly increased and then levelled off. The dietary AA requirement of cobia was estimated to be 44.7 mg kg?1 based on WG, 53.9 mg kg?1 or 104 mg kg?1 based on either hepatic or muscular AA concentration, respectively.  相似文献   

14.
Arginine was hypothesized to be a model compound in the present study on molecular forms of indispensable amino acid (IAA) dietary supplementation. Juvenile South American pacu (Piaractus mesopotamicus) were fed diets containing arginine in a protein base (casein‐wheat gluten or casein‐gelatin), or the casein‐wheat gluten base supplemented with dipeptide or free arginine at two levels (5 and 10 g kg?1). Growth and protein efficiency ratios were significantly affected by diets, but not by arginine molecular form. Three free dispensable amino acids (DAA) and four IAA in plasma were affected by diet, but plasma arginine concentrations did not differ. Plasma urea concentrations, being very low in the pacu, and hepatic arginase activities, were not affected by diet (P = 0.10–0.11), but together with plasma ornithine, mirrored the growth data. Molecular form of arginine supplementation, free or dipeptide, significantly changed several free IAA (Phe, Leu, Ile, His) and urea, with a higher mean plasma concentration in dipeptide fed fish. The dietary treatments, or molecular form of the arginine supplementation, did not change proximate composition, except that calcium levels decreased with higher dietary arginine supplementation level. The present study indicates that dipeptides can provide IAA to pacu, and that arginine supplemented in this form is utilized as efficiently as in free form.  相似文献   

15.
The objective of this study was to evaluate the potential of free amino acids to replace protein‐bound amino acids in diets for Solea senegalensis juveniles. For this purpose, fish with 4.26 g mean initial weight were fed during 55 days with diets containing 500 g kg?1 protein and 100 g kg?1 lipid, based on fish meal and fish oil as main protein and lipid sources (control diet), or diets where 20%, 35% and 50% of fish meal were replaced by crystalline amino acids, using L‐lysine HCl as lysine source. To access the efficiency of the crystalline lysine source, another diet was formulated with 35% fish meal replacement but using L‐lysine sulphate instead of L‐lysine HCl as lysine source. Overall, growth performance, feed utilization, nutrient retention, whole‐body and amino acid composition did not show significant differences among groups. In conclusion, up to 50% protein‐bound amino acids can be replaced by crystalline amino acids in diets for Senegalese sole juveniles without negative effects in fish performance. Additionally, it was shown that L‐lysine sulphate and L‐lysine‐HCl may be used interchangeably by Senegalese sole juveniles, with the potential economic benefits involved.  相似文献   

16.
An attempt was made to increase free amino acids (FAA) concentrations in eggs of red snapper Lutjanus campechanus as part of an induced spawning protocol. Mature female red snapper were given intramuscular injections of human chorionic gonadotropin (HCG) at a 1100 IU kg?1 of female body weight. Immediately after the HCG injection, one set of females received an intramuscular injection of FAA in a buffered saline solution at a dose of 20 mg FAA cocktail kg?1 of body weight. The FAA cocktail was 25% isoleucine, 25% leucine, 25% lysine and 25% valine on a molecular weight basis. A second set of fish did not receive the FAA supplement. Both sets of fish were equally successful in spawning with ovulation occurring 21–32.5 h post injection. Injection of FAA into brooders as eggs began final maturation and hydration resulted in an increase in leucine (nmoles mg egg?1) and a slight increase in isoleucine (nmoles egg?1) in recently ovulated eggs. FAA supplementation via brood injection altered FAA utilization rates by embryos and during larval development, resulted in a greater yolk sac and oil globule reserve in larvae as they approached the time of first feeding.  相似文献   

17.
An 8‐week feeding trial was conducted to investigate the effects of different taurine levels on the growth performance of juvenile white shrimp fed with low‐fishmeal diets. Six level diets of dietary taurine were prepared by the supplementation of taurine (0, 0.4 g kg?1, 0.8 g kg?1, 1.2 g kg?1, 2.0 g kg?1 and 4.0 g kg?1) to a control diet (100 g kg?1 fish meal). Each diet was randomly assigned to triplicate groups of 30 shrimps (0.48 ± 0.0 g), each three times daily. Shrimp fed the 0.4 g kg?1 and 0.8 g kg?1 taurine‐supplemented diets, showed significantly higher weight gain, protein efficiency ratio and protein retention efficiency than those of shrimp fed the other diets. The quadratic regression analysis (y = ?55.59x2 + 187.1x + 750.2 R² = 0.587) indicated that a maximum weight gain occurring at 1.68 g kg?1 of taurine level. The whole body and hepatopancreas taurine contents of the taurine‐supplemented diets were on the same level and higher than those of the control group. Total free amino acid content in the hepatopancreas was significantly affected by taurine supplementation. The results of the present study demonstrate that the white shrimps require taurine as an essential nutrient for growth performance.  相似文献   

18.
Two feeding experiments were conducted to quantify the total sulphur amino acid (TSAA) requirement and replacement value of cystine for methionine for fingerling Labeo rohita. In Experiment I, isonitrogenous (380 g kg?1 CP) and isocaloric (17.90 kJ g?1 GE) amino acid test diets with graded levels of methionine (4, 6, 8, 10, 12, 14 g kg?1 dry diet) and 0.4 g kg?1 cystine were fed to fish (4.62 ± 0.2 cm; 0.66 ± 0.1 g) and methionine requirement determined by analysing absolute weight gain (AWG) (5.48), feed conversion ratio (FCR) (1.26), protein retention efficiency (PRE%) (39%) and energy retention efficiency (ERE%) (85%) data which were best at 10 g kg?1 methionine of dry diet. In Experiment II, six diets with different ratios of L‐cystine and L‐methionine on equimolar sulphur basis were fed to fish (4.71 ± 0.1 cm; 0.69 ± 0.2 g) under identical conditions. Maximum AWG (5.58), best FCR (1.24), PRE (41%) and ERE (86%) in fish fed Diet IV indicated cystine replacement value to be 40%. On the basis of the broken‐line and second‐degree polynomial regression analyses of results obtained in Experiments I and II, it is concluded that inclusion of TSAA in the range of 25.2–31.31 g kg?1 of protein is optimum of which 33–39% could be spared by cystine.  相似文献   

19.
Threonine is the third‐limiting essential amino acid in diets based on cereal ingredients. A 4‐week trial was conducted to determine the threonine requirement of large Nile tilapia based on fish growth, feed efficiency, body composition, protein and amino acid retention. Six hundred fish (563.3 ± 15.1 g) were distributed into twenty 1.2‐m3 cages. Five diets containing 288 g kg?1 of crude protein, 12.7 MJ kg?1 of digestible energy and 8.9, 10.5, 12.2, 13.7 and 15.4 g kg?1 of threonine were elaborated. Fish were hand‐fed five times a day to extruded diets. Significantly, differences in growth performance and amino acids retention among the treatments were observed. Fish fed 10.5 g kg?1 of threonine showed higher daily weight gain, gutted weight and fillet weight (P < 0.05) compared to fish fed with other experimental diets. Diets containing 8.9–15.4 g kg?1 of threonine did not affect whole body and muscle proximate composition. Based on second‐order regression analysis, the dietary threonine requirement estimated based on final gain, fillet weight and fillet yield was 12, 12.1 and 11.5 g kg?1 diet, respectively. The dietary threonine requirement for maximum fillet yield of Nile tilapia was estimated to be 11.5 g kg?1.  相似文献   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号