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1.
The shrimp Penaeus stylirostris is currently produced on a commercial scale in Tahiti and New Caledonia. Both super-intensive (80 animals m−2) and semi intensive (25 m−2) systems are promoted. Locally produced commercial feed contains 380–400 g kg−1 crude protein (CP) without special consideration for environmental impact. The need for a 'low pollution' diet implies reconsideration of the optimum dietary protein level for this species. Under experimental conditions, six isoenergetic practical diets ranging from 270 g kg−1 to 440 g kg−1 CP were formulated and fed to satiation for 30 days to juvenile P. stylirostris ; average growth rates were between 5.5 and 7.5 g per month with survival rates > 90%.
The lowest protein levels 270–310 g kg−1, gave significantly ( P < 0.05) poorer growth (5.5 g per 30 days) than was observed with 330–430 g kg−1 CP; 330 g kg−1 CP may be recommended, and as it is lower than levels in diets used currently, there is a possibility of reducing nitrogenous waste. In addition to growth response, protein efficiency ratio, protein productive value and food conversion (feed/gain) all supported a recommended dietary protein level of 330 g kg−1. Future prospects for practical feeds with even lower CP levels are considered.  相似文献   
2.
Blood metabolites in wild and seventh-generation cultivated shrimp were measured to determine how size-based selection could alter the nutritional and immunological conditions of Litopenaeus vannamei. Wild L. vannamei juveniles and a sample of seventh-generation cultured shrimp were acclimated under identical conditions. During 55 days, shrimp were fed a high (HCHO: 44%) or a low (LCHO: 3%) carbohydrate diet for 55 days. Wild shrimp showed a direct relation between dietary CHO and lactate, protein and hemocyte levels indicating that dietary CHO was used for protein synthesis via transamination pathways. In seventh-generation cultured shrimp these parameters were inversely proportional to dietary CHO level, indicating the capacity to synthesize protein from dietary CHO was repressed in cultured shrimp. Farmed shrimp showed a limited capacity to respond to LCHO diets demonstrating high protein dependence in their metabolism and immune response. These results demonstrate that during size-based breeding programs other metabolic process than CHO catabolism can be selected. The incapacity of shrimp to use dietary CHO could limit protein reduction of diets and limit the efforts of the shrimp industry to be ecologically and environmentally profitable.  相似文献   
3.
The growth response to supplementation of mixed diets with a protein extracted from frozen squid (squid protein fraction: SPF) was tested at levels of 1.5, 3.0, 6.0 and 16.0% in the diet in four species of shrimp: Penaeus stylirostris, P. vannamei, P. monodon and P. indicus. In P. stylirostris and P. vannamei , growth rates were significantly improved by SPF even at the lowest level of supplementation. Improvement was obtained only with 6 and 16 percent in P. monodon , while no significant response was observed in P. indicus. The growth promoting effect of SPF at 16% of the diet could be explained by its nutritional value, particularly by its amino acid content, although all diets were supposed to be well balanced in all known nutrients. However, at lower levels the results obtained seemed to be due to the unknown growth factor (UGF) already mentioned in previous reports.  相似文献   
4.
The relative contributions of feed sources were determined through the isotopic signal (δ13C and δ15N) and fatty acid profile of feed items, shrimp muscle, and eggs of Litopenaeus vannamei reared in a biofloc system. In the growout phase, the isotope analysis showed the biofloc particle size class ≥250 μm contributed 55–100%; size ≥50 < 250 μm contributed 0–22%; and artificial feed contributed 0–45%. Principal component analysis applied to fatty acid profiles showed that biofloc ≥250 μm and artificial feed were the most important items in shrimp growout. For the egg production, isotope analysis suggested that the most important feed sources according to their relative contributions were polychaetes (0–100%), followed by artemia biomass (0–86%) and semi‐moist feed (0–66%), with lower contributions from squid, mussel, and the muscle of L. vannamei broodstock that had been cultured in biofloc. In terms of fatty acids, the most important items were artemia, polychaetes, and semi‐moist feeds. This work clarified the importance of feed sources for shrimp during culture in biofloc systems and during reproduction. Analysis of stable isotopes and fatty acids can be successfully used to trace the assimilation of nutrients during the nutrition of shrimp.  相似文献   
5.
The degree of hydrolysis (DH) of the ingredients was evaluated for Centropomus undecimalis juveniles. The in vitro experiment included wheat gluten (WG), corn gluten (CG), soybean meal (SBM) and pretreated phytase (SBM + phytase), soy protein concentrate (SPC), canola meal (CAN) and pretreated phytase (CAN + phytase), poultry byproduct meal (PBPM), chicken meal (CHKM), dried whey (DW), Pota meal (PM: mix of giant squid, fish soluble protein concentrate, crustacean meal, and fish oil), and Protiblend (PTB: aquatic and render mix). The highest acidic DH occurred with PTB (0.38 ± 0.06), CHKM (0.33 ± 0.3), and PBPM (0.25 ± 0.03). In the alkaline condition, PTB (1.6 ± 0.17 and 0.98 ± 0.05 for pyloric caeca and intestine, respectively) and CG (1.04 ± 0.4 and 0.75 ± 0.2 for caeca and intestine, respectively) provided the highest DH values. In vitro digestibility demonstrated that PTB was the highest (85.3%) followed by PBPM (51.4%), CAN + phytase (47.6%), CG (45.1%), and CHKM (46.5%). The in vivo experiment concerned the WG, CHKM, PBPM, PM, and PTB diets plus a reference diet with fishmeal (Ref diet). The total %DH was different (P < 0.05) with the lowest values for the WG diet (0.34 ± 0.09%) and Ref diet (0.34 ± 0.15). Free amino acid released during digestion was displayed for these diets and a bifactorial analysis produced no difference (P > 0.05). The apparent digestive coefficients ranged from 89.8 to 92.9% for protein and from 68 to 71.4% for energy.  相似文献   
6.
L. vannamei postlarvae are normally raised with a protein dense diet (50% protein) rich in fishmeal. Part of the protein is utilized for energy purpose instead of protein synthesis. Based on a previous energy partitioning study, the effects of two isoenergetic compounded feed treatments – animal protein (AP) and vegetable protein and carbohydrates (VPC) – upon growth efficiency and energy budget of shrimp postlarvae and early juveniles were determined. Recovered energy (RE) or production (P) after 50 days trial was similar (2 J day 1) in both treatments, from PL14 to PL19. However, early juveniles discriminated between animal protein (116 J day 1) and vegetable protein and carbohydrates (88 J day 1). The difference in respiration indicated a higher heat increment with AP compared to VPC. At maintenance level, energy used was lower with AP than VPC treatment. Postlarvae and early juveniles employed protein as a main energy substrate (O:N < 20). Differences in the efficiencies observed in the calculated energy budget were attributed to the presence of carbohydrates in diet and not to the protein source. The advantage of incorporating vegetable protein source in the diet of harvesting shrimp may eventually contribute towards a reduction of fishmeal costs and waste products as well as to achieve sustainable shrimp farming.  相似文献   
7.
The influence of protein and energy levels on growth rate, survival, pre- and post-prandial oxygen consumption, ammonia excretion, haemolymph glucose (HG), glycogen in digestive gland and osmotic pressure (OP) in white shrimp Litopenaeus vannamei (Boone) and L. setiferus (Linne) juveniles was studied. Diets containing a high-quality protein at a protein/energy (P/E) ratio of 16, 26, 31 and 36 mg kJ−1 were fed at 20% of shrimp body weight of two sizes: < 1 g and > 1 g. Both species showed a optimum P/E ratio of 36 mg kJ−1 (33–44% protein and 6–23% carbohydrate) in juveniles < 1 g. For shrimp > 1 g, L. setiferus showed a higher growth rate in the diet with 16 mg kJ−1 (27% protein; 32% carbohydrate) and L. vannamei between 26 and 36 mg kJ−1 (33–44% protein and 6–23% carbohydrate). In both experiments, the growth rate of L. vannamei was 2–3 times that observed in L. setiferus. Routine oxygen consumption and apparent heat increment (AHI) of L. setiferus juveniles was two times higher than that observed in L. vannamei juveniles, which could indicate that L. setiferus has a higher metabolic rate. The O/N ratio varied according to protein level, with higher values (O/N = 180) with a 16-mg kJ−1 diet and lower values (O/N = 73) with a 36-mg kJ−1 diet in L. setiferus juveniles. A similar variation in O/N ratio was obtained in L. vannamei fed with all diets with an interval between 22 and 50. An inverse relation between ammonia excretion and HG, and digestive gland glycogen (DGG) in relation to an increase in the P/E ratio indicate that both shrimp species are well adapted to use carbohydrates and/or proteins from their diet. The higher values of hyper-osmotic capacity (hyper-OC) were observed in L. setiferus < 1 g fed with 36 mg kJ−1 and the lowest in L. vannamei < 1 g fed with 31 mg kJ−1. Intermediate values of hyper-OC were observed in both species fed all diets indicating that osmotic factors of juveniles < 1 g of both species are more affected by the P/E ratio than juveniles > 1 g. All results showed that juveniles > 1 g of both species are less dependent of P/E ratio than juveniles < 1 g. Litopenaeus vannamei is a most tolerant shrimp species with a high capacity to use a wide range of dietary P/E ratios for growth, which may be due to its lower energy requirements. Litopenaeus setiferus showed a lower capacity to accept different P/E ratios but the optimum P/E ratio obtained with this species shows that L. setiferus accept diets with a high carbohydrate level as well. These results demonstrate that there are nutritional and physiological differences that explain the differences that have been observed when both species were cultured in commercial ponds.  相似文献   
8.
This study was designed to test the effect of soy protein (SPC), wheat gluten (WHG) and potato protein (PPC), in vitro and in vivo digestibility of protein and energy in the juveniles Litopeneaus vannamei. A completely random design was used with nine 400‐L tanks (with three repetitions by treatment). Ten respirometric chambers (500 mL) were used for energy distribution. In vitro digestibility for SPC (8.8%) was higher than for PPC (5.8%) and for WHG (4.3%, P < 0.05). Diets’ degree of hydrolysis ranged between 0.75% and 1.2%, with lowest value in potato protein concentrate diet (0.75 ± 0.09%, P < 0.05). No significant differences were obtained in apparent digestibility coefficient (ADC) for protein (63.4–74.1%). ADC for amino acids ranged between 80% and 90%. Daily growth coefficient ranged from 0.86% to 1.1% day−1, being the best in soybean protein concentrate diet (SPCd) (P < 0.05). Significant differences on heat increment were observed (P < 0.05); highest value was in wheat gluten diet (1.0 ± 0.1 kJ shrimp day−1) that coincided with a peak of trypsin specific activity (16.5 ± 3.7 mU mg protein−1). Highest retained energy for growth was observed in shrimp fed SPCd (0.7 ± 0.03 kJ day−1, P < 0.05). Muscle collagen content presented a minimum of bands with SPCd, whereas shrimp post‐mortem collagenase activity was not affected by any of the three diets (P > 0.05).  相似文献   
9.
A 45‐day trial was performed to evaluate the effect of biofloc technology (BFT) with or without fresh food (FF) supplementation during pre‐maturation period on Farfantepenaeus duorarum spawning performance, biochemical composition and fatty acid profile of eggs as compared with conventional clear‐water system (CW+FF). Females raised in biofloc and that received FF supplementation (FLOC+FF) achieved better spawning performance in terms of number of eggs per spawn (49 × 103), number of eggs per spawn per g of spawner's body weight (2.1 × 103) and egg size (~275 μm) as compared with CW+FF (23 × 103, 1.1 × 103 and 263 μm respectively), but both treatments did not vary from FLOC (P > 0.05). High spawning activity was also observed in biofloc system as compared with clear‐water system as shown in number of spawns per ablated female (2.2–3.0 versus 0.6) and percentage of females that spawn at least once (80–82 versus 25%). Biochemical composition of eggs presented no significant differences among treatments. FA profile of eggs indicated that high spawning activity performed by females in FLOC+FF treatment was reflected in lower mean levels of EPA, DHA and sum of polyunsaturated fatty acids (n‐3) and (n‐6). The better reproductive performance demonstrated by females raised in biofloc justified the application of this technology in F. duorarum broodstock.  相似文献   
10.
The effects of two microencapsulated feeds were evaluated on development, growth, survival, proteolytic activity, and biochemical composition of white shrimp, Litopenaeus vannamei, larvae. The treatments were: (1) basal microcapsules (BM), (2) microcapsules containing krill hydrolysate (BMK), and (3) live food control (LFC: Artemia franciscana nauplii) with all treatments receiving algae (Chaetoceros ceratosporum and Tetraselmis chuii). No significant differences were found in development index and survival among larvae. Growth rate was significantly higher in larvae fed LFC (15 ± 0.06%/d) as compared with those offered the BM diet (7.5 ± 0.5%/d) with the BMK (11 ± 0.04%/d) treatment producing intermediate results. The activity of total proteases and chymotrypsin decreased significantly after Mysis I (MI) in larvae fed LFC or BMK. Protein content of larvae increased significantly toward PL1. The acylglycerides content in MIII fed on LFC (2.3 ± 0.2%/dw) was higher than that MI fed BM (1 ± 0.01%/dw). No difference was observed in the cholesterol (CH) content of the larvae. The acylglycerides/protein and cholesterol/protein ratios showed a decreasing pattern between MI and PL1, indicating that these two ratios were related to ontogenetic shifts. These results demonstrate improvements in microparticulate diets when krill hydrolysates are included in the formulation.  相似文献   
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