Comparative Characterization of Enzymatic Digestion from Fish and Soybean Meal from Simulated Digestive Process of Pacific Bluefin Tuna,Thunnus orientalis          下载免费PDF全文

Ariana I. Román‐Gavilanes  Emmanuel Martínez‐Montaño  María Teresa Viana 《Journal of the World Aquaculture Society》2015,46(4):409-420

The digestive process of the Pacific bluefin tuna (PBT), Thunnus orientalis, was simulated through two phases of in vitro digestion: acidic digestion with porcine pepsin, followed by alkaline digestion with pancreatic crude extract (PCE) obtained from the PBT to hydrolyze fish meal (FM) and soybean meal (SBM) as protein substrates. The crude protein from FM resulted in a lower degree of hydrolysis (73.3%) compared with SBM (79.2%). However, the resulting digested products showed that FM contained 35% more small peptides, with sizes <6.5 kDa than those from the starting material (>150 kDa). The SBM had an increase of only 1.3% in the similar peptide cut‐offs found after hydrolysis. These results suggested that FM appeared to be a better source of protein according to the amount of low‐molecular weight peptides. In addition, the proteolytic activity of PCE showed that 88.9% of its alkaline proteolytic activity corresponded to trypsin and 2.9% corresponded to chymotrypsin activity. The results shown here demonstrate that peptide sizes are important in identifying suitable protein sources for aquafeed production to reinforce the primary results obtained from the in vitro digestibility using the pH‐Stat system. These results also contribute to a better understanding of the digestibility process in aquatic organisms.  相似文献   

Brewery residues as a source of organic carbon in Litopenaeus schmitti white shrimp farms with BFT systems     

Michelle Midori Sena Fugimura  Helaine dos Reis Flor  Emanuela Paula de Melo  Tiago Viana da Costa  Wilson Wasielesky Jr.  Lidia Miyako Yoshii Oshiro 《Aquaculture International》2015,23(2):509-522

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川西北草原鼠荒地治理技术研究     

王钰  周俗  赖秀兰  根呷羊批  杨思维  陈立坤  牛培莉  李开章  钟小山 《草原与草坪》2022,(5):73-80

对四川省阿坝州若尔盖县鼠荒地采取“害鼠控制+围栏封育+禁牧+整地施肥+草种补播” 的综合治理措施,并于治理前(2017 年)和治理后(2018—2020 年),采用堵洞开洞法调查高原鼠兔 (Ochotona curzoniae)有效洞口数量,利用植物群落调查法调查植物群落结构和植物物种多样性,分析治理后高原鼠兔相对种群密度、植物群落结构和植物物种多样性的变化。结果显示：治理后第 1 年、第 2 年和第 3 年 ,高原鼠兔有效洞口数分别减少了 90. 4%、90. 6% 和 64. 7%;植物种类分别增加了 60. 0%、40. 0% 和 35. 0%;植被平均高度分别增加了 437. 3%、441. 0% 和 442. 2%;植被盖度增幅分别为 153. 6%、152. 0% 和 140. 8%;平均鲜草产量分别达到 15 862. 5、15 007. 5 和 12 547. 5 kg/hm2 ,比治理前分别增加了 272. 2%、252. 0% 和 194. 3%;丰富度指数 、Shannon ‐Wiener 指数 、Simpson 指数和 Pielou 指数在治理 1 年后分别增加了 60. 0%、26. 0%、11. 6% 和 8. 9%,治理 2 年后分别增加了 40. 0%、 27. 6%、13. 3% 和 14. 7%,治理 3 年后分别增加了 35. 0%、27. 9%、13. 6% 和 16. 3%。该综合治理措施有效地提高了试验区植被的高度、盖度和地上生物量,增加了物种丰富度和多样性指,改变了植物群落结构,降低了高原鼠兔种群密度。  相似文献   

Effect of dietary protein:energy ratio on intake, growth and metabolism of juvenile green abalone Haliotis fulgens     

Laura Gmez-Montes  Zaul García-Esquivel  Louis R. D'Abramo  Armando Shimada  Carlos Vsquez-Pelez  María Teresa Viana 《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):769-780

Juvenile green abalone Haliotis rufescens were grown under laboratory conditions at 21±1 °C and fed formulated diets consisting of different protein:energy ratios (mg protein/kcal), 62, 74, 85, 100, 108, for 60 days. The level of crude protein ranged from approximately 26% to 44% while the energy content remained constant at about 4.1 kcal g⁻¹. Growth ranged from 3.63 to 12.33 mg day⁻¹. The growth of abalone fed the 100 and 108 diets was significantly greater than that of each of the other diets. Protein efficiency ratio increased as the dietary protein content increased except for the T108 diet (44% crude protein). Abalone apparently consume food to satisfy an energy requirement. Caloric expenditure due to metabolism was estimated for abalone fed diets with protein ratios of 62, 85, 100. Energy loss due to respiration did not vary appreciably among abalone fed the different diets. The proportional distribution of dietary energy into fecal, digestible, growth, and metabolic energy was estimated for abalone fed these diets. Apparent dry matter digestibility was among the lowest for abalone fed the 100 P:E diet, but growth of abalone fed this diet was significantly higher than that of each of the other treatments except the 108 diet. Unexplained energy loss to achieve balance ranged from 7% to 28.5%, some of which is probably due to differential mucus and ammonia production. Results suggest a potential for the reduction of both dietary protein and lipid without causing any adverse effects on the growth response.  相似文献   

Variation in life history parameters of the cardinalfish Apogonlineatus     

GEN  KUME  ATSUKO  YAMAGUCHI  ICHIRO  AOKI 《Fisheries Science》2003,69(2):249-259

ABSTRACT:   Life history parameters (growth pattern, the length of the spawningseason and age at sexual maturity) of Apogon lineatus wereinvestigated from three localities in Japan. The maximum ages werefound to be 3 years in Tokyo Bay, 2 years in Osaka Bay and 5 yearsoff Niigata Prefecture. Both sexes from Tokyo Bay grew to largersizes between the ages of 1 and 2 years than both sexes from otherlocalities, food availability being suggested as the major factorfor differences in growth. Spawning seasons were during 4 months(July–October) in Tokyo Bay and Osaka Bay, but were foundto only occur during the two months of July and August off NiigataPrefecture. Factors that could limit the spawning season off NiigataPrefecture were not determined. Age at maturity for both sexes inall localities appeared to be 1 year. We could not elucidate whetherthese variations in life history parameters arose from genetic differencesor from phenotypic plasticity. In either case, the trade-off betweenthe maximum age and the length of the spawning season in the offNiigata Prefecture population and any other population may be interpretedas an adaptation to local conditions, such as with the off NiigataPrefecture population.  相似文献   

Fall Armyworm Damaged Maize Plant Identification using Digital Images   总被引：6，自引：0，他引：6  

D. G. Sena Jr  F. A. C. Pinto  D. M. Queiroz  P. A. Viana 《Biosystems Engineering》2003,85(4):449-454

The objectives of precision agriculture are profit maximisation, agricultural input rationalisation and environmental damage reduction, by adjusting the agricultural practices to the site demands. The fall armyworm (Spodoptera frugiperda) is one of the most important maize pests in Brazil and the use of insecticide is the main control method. It is believed that site-specific control can be implemented by using a machine vision system. The objective of this work was to develop and evaluate an algorithm at simplified lighting conditions for identifying damaged maize plants by the fall armyworm using digital colour images. Images of damaged and non-damaged maize plants were taken in eight different stages and in three different light intensities. The proposed algorithm had two stages: the processing and the image analysis. During the first stage, the images were processed to create binary images where the leaves were segmented from the other pixels. At the second stage, the images were subdivided into blocks and classified as ‘damaged’ or ‘non-damaged’ depending on the number of objects found in each block. The algorithm correctly classified 94·72% of 720 images.  相似文献   

基于农用地分等定级的耕地入选基本农田定量方法研究——以河北省卢龙县为例     

耿志阔  张俊梅  许皞  周亚鹏 《安徽农业科学》2007,35(3):844-845,877

应用农用地分等定级中间成果,以农用地分等定级划分的单元为基础,对影响耕地入选基本农田的其他因素进行了综合考虑,然后对每个单元的耕地质量进行量化,提出了一套从质量上定量的划定基本农田的新方法.  相似文献   

Hanbury Brown Twiss effect for ultracold quantum gases     

Schellekens M  Hoppeler R  Perrin A  Gomes JV  Boiron D  Aspect A  Westbrook CI 《Science (New York, N.Y.)》2005,310(5748):648-651

We have studied two-body correlations of atoms in an expanding cloud above and below the Bose-Einstein condensation threshold. The observed correlation function for a thermal cloud shows a bunching behavior, whereas the correlation is flat for a coherent sample. These quantum correlations are the atomic analog of the Hanbury Brown Twiss effect. We observed the effect in three dimensions and studied its dependence on cloud size.  相似文献   

Follow-up of mercury levels in fish,human hair and urine in the Madeira and Tapajós basins,Amazon, Brazil     

Malm  O  Guimarães  JRD  Castro  MB  Bastos  WR  Viana  JP  Branches  FJP  Silveira  EG  Pfeiffer  WC 《Water, air, and soil pollution》1997,97(1-2):45-51

Informal economy of gold mining has contaminated some important river basins in Amazon. Follow-up studies on critical compartments showed some areas with high Hg levels in fish as well as in human hair samples. Average Hg in piscivorous fish in the Madeira river itself was 846 ppb (N=284) with a maximum of 3921 ppb. Mercury in fish from non polluted areas in this basin shows high variability, even for single species. A seasonal variation in Hg content was observed, with higher values at the end of the dry season. In the upper Tapajós basin comparable values were found for fish but with a definite decreasing trend downstream. Average value for piscivorous fish in the whole Tapajós basin is 482 ppb (N=122) with a maximum value of 3770 ppb. Hair Hg was higher in fishing villages in the Tapajós (average: 17 ppm; with N=432 and maximum value of 176 ppm) than in the Madeira (average: 9 ppm; N=169; maximum 71 ppm), and data from some areas of the Tapajós suggest a decrease with time. Mercury was much higher in urine of goldshop workers in Santarém (low Tapajós) than in Alta Floresta (high Tapajbs) and show a decreasing trend in both cases, probably related to the significant decline in gold mining activities during the study period (1986–1994).  相似文献   

冰川棘豆对山羊的毒性试验   总被引：1，自引：0，他引：1  

李勤凡  王建华  齐雪茹  谭远友  耿果霞 《中国兽医学报》2005,25(5):511-513

10只杂种奶山羊随机等分为试验组和对照组，试验组羊按每日10g／kg的剂量饲喂冰川棘豆干粉，定期采血，测定血液常规指标和生化指标，进行病理学检验。结果表明，RBC、Hb、PCV、MCH、MCV、MCHC显著低于对照组（P〈0．01），淋巴细胞出现空泡变性。试验组羊血清碱性磷酸酶（AKP）活性，从试验的第7天起持续升高；从试验的第14天起，血清谷草转氨酶（GOT）、乳酸脱氢酶（LDH）活性，尿素氮（BUN）含量明显高于对照组；在试验的35～49d，血清淀粉酶活性持续升高，与对照组比较差异显著（P〈0．05或P〈0．01）；从试验的第7天起，血清α-甘露糖苷糖（AMA）活性显著低于对照组（P〈0．01），说明冰川棘豆对心、肝、肾、脑等器官有一定的毒害作用，冰川棘豆中含有吲哚兹啶生物碱。病理组织学检查中发现，心、肝、脾、肺、肾、脑、卵巢等组织普遍发生空泡变性。  相似文献