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91.
Alan FRANZLUEBBERS Derek HUNT Gary TELFORD Shabtai BITTMAN Quirine KETTERINGS 《农业科学与工程前沿(英文版)》2021,8(1):81-96
92.
盐碱地鱼池水化学因子与浮游植物的调查研究 总被引:3,自引:0,他引:3
对山东黄河两岸和河口地区盐碱地鱼池的水化学因子与浮游植物进行了调查研究,确认鱼池水型属ClⅢ^Na,ClⅡ^Na和ClⅠ^Na型的氯化水,pH变化在7.6-8.9之间,盐度在0.9-8之间,营养盐含量比一般淡水鱼池低,浮植物甚至不如小型水库,湖泊丰富。 相似文献
93.
ABSTRACTThis study investigated the morphometrics, proximate chemical compositions, pH, total amino acid (TAA), fatty acid profile, and minerals of the processing by-products of Antarctic krill (Euphausia superba). The nutrient compositions and properties of the by-products were revealed by being compared to those of Antarctic krill muscle and the economically important species of freshwater prawns (Macrobrachium nipponense) and penaeid shrimps (Metapenaeus ensis). The by-products are worthy of utilization because of the high ratio to the total weight (65.7%). The crude protein contents in the muscle and by-products of krill are 17.4 and 11.7%, respectively. The krill proteins have higher contents of essential amino acids (EAAs). The EAAs constitute 42 and 37% of the TAAs in muscle and by-products, respectively. The krill processing by-products contain high levels of total lipid (3.3%), and polyunsaturated fatty acids constitute 34% of fatty acids with high levels of eicosapentaenoic acid (EPA; 19.08%) and docosahexaenoic acid (DHA; 10.02%). Krill meat provides considerable iron, zinc, calcium, selenium, and copper. It is imperative to lower the fluoride level (70.1 mg/kg, wet basis) in krill muscle. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) reveals that myosin heavy chain (MHC) and actin are the major proteins in muscle, and their contents vary between species. 相似文献
94.
Janaina Mitsue Kimpara Fabricio Ribeiro Tito Rosa Bruno de Lima Preto Wagner C Valenti 《Aquaculture Research》2011,42(9):1289-1297
We evaluated the water characteristics and particle sedimentation in Macrobrachium amazonicum (Heller 1862) grow‐out ponds supplied with a high inflow of nutrient‐rich water. Prawns were subject to different stocking and harvesting strategies: upper‐graded juveniles, lower‐graded juveniles, non‐graded juveniles+selective harvesting and traditional farming (non‐grading juveniles and total harvest only). Dissolved oxygen, afternoon N‐ammonia and N‐nitrate and soluble orthophosphate were lower in the ponds in comparison with inflow water through the rearing cycle. Ponds stocked with the upper population fraction of graded prawns showed higher turbidity, total suspended solids and total Kjeldahl nitrogen than the remaining treatments. An increase in the chemical oxygen demand:biochemical oxygen demand ratio from inlet (4.9) to pond (7.1–8.0) waters indicated a non‐readily biodegradable fraction enhancement in ponds. The sedimentation mean rate ranged from 0.08 to 0.16 mm day?1 and sediment contained >80% of organic matter. The major factors affecting pond ecosystem dynamic were the organic load (due to primary production and feed addition) and bioturbation caused by stocking larger animals. Data suggest that M. amazonicum grow‐out in ponds subjected to a high inflow of nutrient‐rich water produce changes in the water properties, huge accumulation of organic sediment at the pond bottom and non‐readily biodegradable material in the water column. However, the water quality remains suitable for aquaculture purposes. Therefore, nutrient‐rich waters, when available, may represent a source of unpaid nutrients, which may be incorporated into economically valued biomass if managed properly. 相似文献
95.
96.
正鲇形目鱼包含35个科。其中斑点叉尾(Ietalurus punetaus)、黄颡鱼(Pelteobagrus fulvidraco)、长吻(Leiocassis longirostris)、斑鳠(Mystus guttatus)、胡子鲇(Clarias fuscus)等品种肉质鲜美、营养丰富,是我国重要的淡水经济鱼类,深受广大消费者的青睐。鲇形目鱼类的市场需求持续增加,养殖规模也不断扩大。有关鲇形目鱼幼鱼、成鱼等营养饲料方面的研究报道较多,但其亲鱼和仔稚鱼营养素需求及配合饲料研究相对滞后。 相似文献
97.
Protein and energy nutrition of brook trout (Salvelinus fontinalis) at optimal and elevated temperatures 下载免费PDF全文
The digestible protein (DP) and digestible energy (DE) requirements for maintenance and growth of brook trout (Salvelinus fontinalis) were determined using a factorial model at either optimum (15 °C) or elevated temperature (19 °C). Several key parameters of the factorial model were measured using a series of inter‐related studies. The maintenance requirements for DP and DE were 0.10 gDP kg?0.69 day?1 (15 °C) and 0.31 gDP kg?0.78 day?1 (19 °C), and 34.86 kJDE kg?0.84 day?1 (15 °C) and 46.14 kJDE kg?0.86 day?1 (19 °C). The total requirements for DP were 0.10 gDP kg?0.69 day?1 + 2.14PG (protein gain) (15 °C) and 0.31 gDP kg?0.78 day?1 + 1.98PG (19 °C). The total requirements for DE were 36.86 kJDE kg?0.84 day?1 + 1.58EG (energy gain) (15 °C) and 46.14 kJDE kg?0.86 day?1 + 1.64EG (19 °C). The partial efficiencies for growth were 0.47 (15 °C) and 0.51 (19 °C) for protein, and 0.63 (15 °C) and 0.61 (19 °C) for energy. Nutrient gain was lower at the elevated temperature; however, feed formulation for brook trout should be adjusted to match changes in nutrient requirements at different culture temperatures. The protein and energy requirements model will be useful for developing commercial feeds and feeding charts for brook trout. 相似文献
98.
The effect of taurine supplementation to a plant‐based diet for barramundi (Lates calcarifer) with varying methionine content 下载免费PDF全文
The effect of variable taurine inclusion (Tau) (1 g/kg DM to 15 g/kg DM) in the diet of juvenile barramundi (Lates calcarifer) on growth and nutrient utilization was investigated at three levels of dietary methionine (Met) supplementation. Diets were fed to juvenile barramundi (starting weight: 26.8 g) twice daily under a restricted pair‐fed regime for a period of 42 days. No significant effect of dietary Tau supply on growth or nutrient utilization was observed at any level of Met inclusion. Numerical variations suggested a positive effect of Tau provision at the mid‐level of supplementation (6–8 g/kg DM). The best‐fit response model (5‐SKM), fitted to the percentage body weight gain data of fish fed diets with an adequate level of Met, suggested a relatively weak pattern of response (R2 = 0.183) and predicted a Tau requirement of 5.47 g/kg DM (9.64 g/kg CP) similar to that reported for several other species. It was concluded that taurine appears to be conditionally essential to barramundi, whereby provision in the diet when sulphur amino acid supply is insufficient to meet biosynthetic demands may be beneficial, but that the predicted requirement is likely reasonably accurate for use as a minimum level of inclusion. 相似文献
99.
分析了经1.5%木瓜蛋白酶55℃酶解3 h后的南极磷虾(Euphausia superba)蛋白酶解产物(上清和沉淀)的营养组成。结果显示:南极磷虾水解度为44.24%;上清冻干物(FDS)中粗蛋白和总糖含量分别为67.13%和13.91%,其必需氨基酸总量(ΣEAA)、鲜味氨基酸总量(ΣDAA)、牛磺酸Tau含量及F值(支链氨基酸/芳香族氨基酸)较酶解前分别提高了8.96%、6.06%、39.10%和16.67%,表明其氨基酸营养价值较酶解前要高。沉淀冻干物(FDP)中粗蛋白和总糖含量分别为44.49%和10.40%,而粗脂肪含量高达33.28%。FDP中总氨基酸含量(ΣAA)、ΣEAA、ΣDAA、Tau含量及F值均下降,但其ΣEAA在ΣAA中的比例高于40%,且8种EAA含量评分均高于FAO/WHO评分模式要求。脂肪酸分析结果表明,FDP中含有饱和脂肪酸(SFA)8种(44.81%),单不饱和脂肪酸(MUFA)6种(27.55%),多不饱和脂肪酸(PUFA)7种(27.64%),二十碳五烯酸EPA和二十二碳六烯酸DHA含量较丰富。研究认为在本实验条件下通过木瓜蛋白酶酶解南极磷虾得到的FDS和FDP具有较高的利用价值,可开发为人类重要的蛋白来源。 相似文献
100.
Jeleel O. Agboola Emma Teuling Peter A. Wierenga Harry Gruppen Johan W. Schrama 《Aquaculture Nutrition》2019,25(4):783-797
The rigid cell walls of microalgae may hinder their utilization in fish feeds. The current experiment assessed the correlation between the accessibility of microalgae nutrients and their in vivo digestibility in African catfish. Nannochloropsis gaditana biomass was subjected to physical or mechanical treatments to weaken its cell wall; untreated—no disruption treatment (UNT), pasteurization (PAS), freezing (FRO), freeze‐drying (FRD), cold pasteurization (L40) and bead milling (BEM). Six experimental diets formulated from differently treated and untreated microalgae (at 30% diet inclusion level) were tested on growth performance and apparent nutrient digestibility (ADCs) in juvenile African catfish. A basal diet (REF) containing no microalgae was used as reference diet. Results showed that biomass gain and feed conversion ratio of fish fed L40 and BEM diets increased by 13% and 11%, respectively, relative to the UNT diet. Additionally, FRD, FRO, L40 and BEM cell wall disruption treatments improved protein digestibility by 0.5%, 5.9%, 8.4% and 16.3%, respectively, compared to the UNT treatment. There was a positive correlation between accessibility of microalgal nutrients and their digestibility in African catfish. Nutrient digestibility of microalgae was dependent on extent of cell disruption. Also, the impact of cell disruption on nutrient digestibility of microalgae differs between African catfish and Nile tilapia. 相似文献