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Dietary organic acids ameliorate high stocking density stress-induced intestinal inflammation through the restoration of intestinal microbiota in broilers 被引量:3
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作者 Dong Dai Guanghai Qi +5 位作者 Jing Wang Haijun Zhang Kai Qiu Yanming Han Yuanyuan Wu Shugeng Wu 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第2期745-759,共15页
Background:High stocking density(HSD)stress has detrimental effects on growth performance,intestinal barrier function,and intestinal microbiota in intensive animal production.Organic acids(OA)are widely used as feed a... Background:High stocking density(HSD)stress has detrimental effects on growth performance,intestinal barrier function,and intestinal microbiota in intensive animal production.Organic acids(OA)are widely used as feed addi-tives for their ability to improve growth performance and intestinal health in poultry.However,whether dietary OA can ameliorate HSD stress-induced impaired intestinal barrier in broilers remains elusive.In this study,a total of 528 one-day-old male Arbor Acres broilers were randomly allocated into 3 treatments with 12 replicates per treatment including 10 birds for normal stocking density and 17 birds for HSD.The dietary treatments were as follows:1)Normal stocking density+basal diet;2)HSD+basal diets;3)HSD+OA.Results:HSD stress can induce increased levels of serum corticosterone,lipopolysaccharides,interleukin-1β,tumor necrosis factor-α,and down-regulated mRNA expression of ZO-1,resulting in compromised growth performance of broilers(P<0.05).Dietary OA could significantly reduce levels of serum corticosterone,lipopolysaccharides,interleukin-1β,and tumor necrosis factor-α,which were accompanied by up-regulated interleukin-10,mRNA expres-sion of ZO-1,and growth performance(P<0.05).Moreover,OA could down-regulate the mRNA expression of TLR4 and MyD88 to inhibit the NF-κB signaling pathway(P<0.05).Additionally,HSD stress significantly decreased the abundance of Bacteroidetes and disturbed the balance of microbial ecosystems,whereas OA significantly increased the abundance of Bacteroidetes and restored the disordered gut microbiota by reducing competitive and exploita-tive interactions in microbial communities(P<0.05).Meanwhile,OA significantly increased the content of acetic and butyric acids,which showed significant correlations with intestinal inflammation indicators(P<0.05).Conclusions:Dietary OA ameliorated intestinal inflammation and growth performance of broilers through restor-ing the disordered gut microbial compositions and interactions induced by HSD and elevating short-chain fatty acid production to inhibit the TLR4/NF-κB signaling pathway.These findings demonstrated the critical role of intestinal microbiota in mediating the HSD-induced inflammatory responses,contributing to exploring nutritional strategies to alleviate HSD-induced stress in animals. 展开更多
关键词 BROILER High stocking density Intestinal inflammation Intestinal microbiota Organic acid Short-chain fatty acid
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Growth, Population Parameters and Stock Status of Sarotherodon galilaeus in Samandeni Reservoir, Burkina Faso
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作者 Nomwine Da Raymond Ouedraogo +1 位作者 Mahamoudou Minoungou Adama Oueda 《Open Journal of Ecology》 2024年第4期257-273,共17页
Mango tilapia, Sarotherodon galilaeus is one of the most caught fish species in the Samandeni multi-species fishing sites of which, few data on its biology and exploitation are available. The study aimed to Assess the... Mango tilapia, Sarotherodon galilaeus is one of the most caught fish species in the Samandeni multi-species fishing sites of which, few data on its biology and exploitation are available. The study aimed to Assess the stock status of S. galilaeus. Sampling was conducted from March, 2021 to February 2022 based on commercial fish catches to analyze growth parameters, first sexual maturity size and harvest status of the stock. A total of 572 specimens including 297 females and 275 males were examined. The stock assessment was performed by using the Length based Bayesian method of Biomass (LBB) and that of growth by the ELEFAN method. The growth parameters showed a seasonality of growth and females appeared to grow faster than males. On the other hand, males had a greater asymptotic length than females. Results on the estimated length of fish at first maturity showed that females firstly reached the maturity compared to males. The relative biomass (B/B<sub>0</sub>) estimated for the stock was higher than the relative biomass that produces maximum sustainable yield (B<sub>MSY</sub>/B<sub>0</sub>) indicating healthy biomass. In addition, the length at first sexual maturity was less than the length at the first catch, indicating the absence of overfishing of growth. In addition, extending the study to the various stocks of the reservoir would be important for the sustainable management of the Samandeni high economic fishing area. 展开更多
关键词 GROWTH stock Status Sarotherodon galilaeus Samandeni Reservoir MATURITY
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Structured Multi-Head Attention Stock Index Prediction Method Based Adaptive Public Opinion Sentiment Vector
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作者 Cheng Zhao Zhe Peng +2 位作者 Xuefeng Lan Yuefeng Cen Zuxin Wang 《Computers, Materials & Continua》 SCIE EI 2024年第1期1503-1523,共21页
The present study examines the impact of short-term public opinion sentiment on the secondary market,with a focus on the potential for such sentiment to cause dramatic stock price fluctuations and increase investment ... The present study examines the impact of short-term public opinion sentiment on the secondary market,with a focus on the potential for such sentiment to cause dramatic stock price fluctuations and increase investment risk.The quantification of investment sentiment indicators and the persistent analysis of their impact has been a complex and significant area of research.In this paper,a structured multi-head attention stock index prediction method based adaptive public opinion sentiment vector is proposed.The proposedmethod utilizes an innovative approach to transform numerous investor comments on social platforms over time into public opinion sentiment vectors expressing complex sentiments.It then analyzes the continuous impact of these vectors on the market through the use of aggregating techniques and public opinion data via a structured multi-head attention mechanism.The experimental results demonstrate that the public opinion sentiment vector can provide more comprehensive feedback on market sentiment than traditional sentiment polarity analysis.Furthermore,the multi-head attention mechanism is shown to improve prediction accuracy through attention convergence on each type of input information separately.Themean absolute percentage error(MAPE)of the proposedmethod is 0.463%,a reduction of 0.294% compared to the benchmark attention algorithm.Additionally,the market backtesting results indicate that the return was 24.560%,an improvement of 8.202% compared to the benchmark algorithm.These results suggest that themarket trading strategy based on thismethod has the potential to improve trading profits. 展开更多
关键词 Public opinion sentiment structured multi-head attention stock index prediction deep learning
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Design Strategies and Practice Paths for Improving Urban Quality in the Stock Era
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作者 Li Tianfei Zhou Xiaotian +1 位作者 Han Shengsheng Liu Yuxuan 《Journal of Landscape Research》 2024年第2期18-24,共7页
In the middle and later stages of urbanization development,the growth of the real estate industry will stagnate,and urban renewal will become the mainstream.With the advancement of urban renewal,there are still proble... In the middle and later stages of urbanization development,the growth of the real estate industry will stagnate,and urban renewal will become the mainstream.With the advancement of urban renewal,there are still problems in improving the quality of cities in the stock era and their design strategies.This paper analyzed the Linping Old City organic renewal project and the Xishui River ecological governance project in the stock era of urban quality improvement by sorting out the current development status,historical background,planning types,and design strategies of quality improvement in the stock era from the perspective of urban renewal,combining with project overview,main problems,design methods,and design content.Urban renewal is the leading direction for promoting urban development and construction on a global scale,and countries formulate different plans and practices based on their local characteristics.Urban renewal strategies should be diversified,and focus on livable environments,urban characteristics,etc.,while considering human factors,green innovation,etc.,in order to achieve smart community management and enhance the economic and social benefits brought by urban attractiveness.For successful cases such as the Linping Old City and Xishui River ecological governance project,corresponding urban quality improvement strategies and implementation plans should be formulated according to local conditions,with emphasis on social participation and people’s livelihood improvement.This study can help urban planning pay more attention to rational utilization and upgrading of existing urban resources,adapt to the current urban development situation,and promote sustainable urban development. 展开更多
关键词 stock era Organic renewal Ecological governance Linping Old City Xishui River
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Exploring the Relationship Between Patent Forward Citation and Stock Return Rate Using Empirical Data of China Stock Market
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作者 Hong-Wen Tsai Hui-Chung Che 《Management Studies》 2024年第2期67-83,共17页
A novel indicator called price-citation was proposed.Based on the company integrated patent database of China listed companies of common stocks(A-shares)with the stock price and the stock return rate data,more than tw... A novel indicator called price-citation was proposed.Based on the company integrated patent database of China listed companies of common stocks(A-shares)with the stock price and the stock return rate data,more than two thousand of A-shares from 2017 to 2020 were selected.The effect of the traditional patent forward citation and the price-citation for discriminating the stock return rate was thoroughly analyzed via ANOVA.The A-shares of forward citation counts above the average showed higher stock return rate means than the A-shares having patents but receiving no forward citations.The price-citation,combining both the financial and patent attributes,defined as the multiplication of the current stock price and the currently receiving forward citation count,showed its excellence in discriminating the stock return rate.The A-shares of higher price-citation showed significantly higher stock return rate means while the A-shares of lower price-citation showed significantly lowest stock return rate means.The price-citation effect had not been changed by COVID-19 though COVID-19 affected the social and economic environment to a considerable extent in 2020. 展开更多
关键词 China A-share PATENT ANOVA stock return rate forward citation price-citation
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Soil Organic Carbon Stock Variation under Different Soil Types and Land Uses in the Sub-Humid Noun Plain, Western Cameroon
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作者 Frank Abigail Sobze Kenfack Georges Kogge Kome +2 位作者 Achille Bienvenue Ibrahim Viviane Pauline Mandah Dieudonne Bitondo 《Open Journal of Soil Science》 2024年第4期191-209,共19页
This study was conducted to assess the current stock of soil organic carbon under different agricultural land uses, soil types and soil depths in the Noun plain in western Cameroon. Three sites were selected for the s... This study was conducted to assess the current stock of soil organic carbon under different agricultural land uses, soil types and soil depths in the Noun plain in western Cameroon. Three sites were selected for the study, namely Mangoum, Makeka and Fossang, representative of the three dominant soil types of the noun plain (Andosols, Acrisols and Ferralsols). Three land uses were selected per site including natural vegetation, agroforest and crop field. Soil was sampled at three depths;0 - 20 cm, 20 - 40 cm, and 40 - 60 cm. Analysis of variance showed that soil type did not significantly influence carbon storage, but rather land uses and soil depth. SOCS decreased significantly with depth in all the sites, with an average stock of 66.3 ± 15.8 tC/ha at 0 - 20 cm, compared to an average stock of 33.3 ± 7.4 tC/ha at 40 - 60 cm. SOCS was significantly highest in the natural formation with 57.2 ± 19.7 tC/ha, and lowest in cultivated fields, at 37.7 ± 10.6 tC/ha. Andosols, with their high content of coarse fragments, stored less organic carbon than Ferralsols and Acrisols. 展开更多
关键词 Carbon stocks Soil Type Soil Depth Agricultural Land Use Noun Plain
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National Soil Organic Carbon Stocks Inventories under Different Mangrove Forest Types in Gabon
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作者 Rolf Gaël Mabicka Obame Neil-Yohan Musadji +5 位作者 Jean Hervé Mve Beh Lydie-Stella Koutika Jean Aubin Ondo Farrel Nzigou Boucka Michel Mbina Mounguengui Claude Geffroy 《Open Journal of Forestry》 2024年第2期127-140,共14页
Gabonese’s estuary is an important coastal mangrove setting and soil plays a key role in mangrove carbon storage in mangrove forests. However, the spatial variation in soil organic carbon (SOC) storage remain unclear... Gabonese’s estuary is an important coastal mangrove setting and soil plays a key role in mangrove carbon storage in mangrove forests. However, the spatial variation in soil organic carbon (SOC) storage remain unclear. To address this gap, determining the SOC spatial variation in Gabonese’s estuarine is essential for better understanding the global carbon cycle. The present study compared soil organic carbon between northern and southern sites in different mangrove forest, Rhizophora racemosa and Avicennia germinans. The results showed that the mean SOC stocks at 1 m depth were 256.28 ± 127.29 MgC ha<sup>−</sup><sup>1</sup>. Among the different regions, SOC in northern zone was significantly (p p < 0.001). The deeper layers contained higher SOC stocks (254.62 ± 128.09 MgC ha<sup>−</sup><sup>1</sup>) than upper layers (55.42 ± 25.37 MgC ha<sup>−</sup><sup>1</sup>). The study highlights that low deforestation rate have led to less CO<sub>2</sub> (705.3 Mg CO<sub>2</sub>e ha<sup>−</sup><sup>1</sup> - 922.62 Mg CO<sub>2</sub>e ha<sup>−</sup><sup>1</sup>) emissions than most sediment carbon-rich mangroves in the world. These results highlight the influence of soil texture and mangrove forest types on the mangrove SOC stocks. The first national comparison of soil organic carbon stocks between mangroves and upland tropical forests indicated SOC stocks were two times more in mangroves soils (51.21 ± 45.00 MgC ha<sup>−</sup><sup>1</sup>) than primary (20.33 ± 12.7 MgC ha<sup>−</sup><sup>1</sup>), savanna and cropland (21.71 ± 15.10 MgC ha<sup>−</sup><sup>1</sup>). We find that mangroves in this study emit lower dioxide-carbon equivalent emissions. This study highlights the importance of national inventories of soil organic carbon and can be used as a baseline on the role of mangroves in carbon sequestration and climate change mitigation but the variation in SOC stocks indicates the need for further national data. 展开更多
关键词 Mangroves Forest Soil Organic Carbon stocks Rizophora Racemose Avicenia germinans GABON
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Stock Price Prediction Based on the Bi-GRU-Attention Model
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作者 Yaojun Zhang Gilbert M. Tumibay 《Journal of Computer and Communications》 2024年第4期72-85,共14页
The stock market, as one of the hotspots in the financial field, forms a data system with a huge volume of data and complex relationships between various factors, making stock price prediction an area of keen interest... The stock market, as one of the hotspots in the financial field, forms a data system with a huge volume of data and complex relationships between various factors, making stock price prediction an area of keen interest for further in-depth mining and research. Mathematical statistics methods struggle to deal with nonlinear relationships in practical applications, making it difficult to explore deep information about stocks. Meanwhile, machine learning methods, particularly neural network models and composite models, which have achieved outstanding results in other fields, are being applied to the stock market with significant results. However, researchers have found that these methods do not grasp the essential information of the data as well as expected. In response to these issues, researchers are exploring better neural network models and combining them with other methods to analyze stock data. Thus, this paper proposes the ABiGRU composite model, which combines the attention mechanism and bidirectional gated recurrent unit (GRU) that can effectively extract data features for stock price prediction research. Models such as LSTM, GRU, and Bi-LSTM are selected for comparative experiments. To ensure the credibility and representativeness of the research data, daily stock price indices of BYD are chosen for closing price prediction studies across different models. The results show that the ABiGRU model has a lower prediction error and better fitting effect on three index-based stock prices, enhancing the learning efficiency of the neural network model and demonstrating good prediction stability. This suggests that the ABiGRU model is highly adaptable for stock price prediction. 展开更多
关键词 Machine Learning Attention Mechanism LSTM Neural Network ABiGRU Model stock Price Prediction
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China’s Monetary Policy Impacts on Money and Stock Markets
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作者 Fang Fang 《Proceedings of Business and Economic Studies》 2024年第2期46-52,共7页
This study investigated the impact of China’s monetary policy on both the money market and stock markets,assuming that non-policy variables would not respond contemporaneously to changes in policy variables.Monetary ... This study investigated the impact of China’s monetary policy on both the money market and stock markets,assuming that non-policy variables would not respond contemporaneously to changes in policy variables.Monetary policy adjustments are swiftly observed in money markets and gradually extend to the stock market.The study examined the effects of monetary policy shocks using three primary instruments:interest rate policy,reserve requirement ratio,and open market operations.Monthly data from 2007 to 2013 were analyzed using vector error correction(VEC)models.The findings suggest a likely presence of long-lasting and stable relationships among monetary policy,the money market,and stock markets.This research holds practical implications for Chinese policymakers,particularly in managing the challenges associated with fluctuation risks linked to high foreign exchange reserves,aiming to achieve autonomy in monetary policy and formulate effective monetary strategies to stimulate economic growth. 展开更多
关键词 Chinese money market Chinese stocks market Monetary policy Shanghai Interbank Offered Rate(SHIBOR) Vector error correction models
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Effects of dietary tryptophan and stocking density on the performance,meat quality,and metabolic status of broilers 被引量:4
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作者 Bo Wang Zhizhi Min +2 位作者 Jianmin Yuan Bingkun Zhang Yuming Guo 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2015年第1期90-96,共7页
Background: Highly automated cage-rearing systems are becoming increasingly popular in China. However, a high stocking density can cause oxidative stress and decrease broiler performance. The tryptophan (TRP) deriv... Background: Highly automated cage-rearing systems are becoming increasingly popular in China. However, a high stocking density can cause oxidative stress and decrease broiler performance. The tryptophan (TRP) derivative 5-hydroxytryptophan (5-HT) has been shown to preserve membrane fluidity in birds suffering from oxidative stress Therefore, this experiment was conducted to determine the effects of dietan/TRP supplementation on performance, breast meat quality and oxidative stress in broilers reared in cages with a high or low stocking density. Methods: Female Arbor Acres broilers (25-d-old, n = 144) were randomly allocated to 1 of 4 treatments. The birds were fed a diet based on corn, soybean meal, cottonseed meal and corn gluten meal containing either 0.18 or 0.27% TRP and were housed with stocking densities of 11 or 15.4 birds/m2 in a 2 x 2 factorial experiment. Broiler performance was evaluated from d 25 to 42. Eight birds from each treatment were slaughtered on d 42 and plasma and breast muscle samples were collected to measure biochemical indices. Results: A higher stocking density tended to be associated with reduced weight gain (P 〈 0.10), and significantly increased plasma glutamic-pyruvic transaminase (GPT) activity (P 〈 0.001). Increased dietary TRP significantly reduced the activities of lactic dehydrogenase and GPT while increasing total cholesterol in the plasma (P 〈 0.01), reducing drip loss of breast muscle (P 〈 0.10) and improving feed efficiency (P 〈 0.10). Conclusions: An increase in dietary TRP, ].S-fold higher than the standard supplementation level, can alleviate oxidative stress as well as improve welfare and feed efficiency in broilers reared in cages with a high stocking density. 展开更多
关键词 BROILER Meat quality PERFORMANCE stocking density TRYPTOPHAN
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Effects of stocking density on the growth and immunity of Atlantic salmon salmo salar reared in recirculating aquaculture system(RAS) 被引量:3
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作者 WANG Yanfeng CHI Liang +5 位作者 LIU Qinghua XIAO Yongshuang MA Daoyuan XIAO Zhizhong XU Shihong LI Jun 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2019年第1期350-360,共11页
Atlantic salmon reared in recirculating aquaculture system(RAS) may lead to inappropriately high stocking density, because ?sh live in a limited space. Finding the suitable stocking density of Atlantic salmon reared i... Atlantic salmon reared in recirculating aquaculture system(RAS) may lead to inappropriately high stocking density, because ?sh live in a limited space. Finding the suitable stocking density of Atlantic salmon reared in RAS is very important for RAS industry. In this paper, the in?uence of stocking density on growth and some stress related physiological factors were investigated to evaluate the ef fects of stocking density. The ?sh were reared for 220 days at ?ve densities(A: 24 kg/m^3; B: 21 kg/m^3; C: 15 kg/m^3; D: 9 kg/m^3 and E: 6 kg/m^3). The results show that 30 kg/m^3 might be the maximum density which RAS can af ford in China. The stocking densities under 30 kg/m^3 have no ef fect on mortality of Atlantic salmon reared in RAS. However, the speci?c growth rate(SGR), ?nal weight and weight gain in the high density group were signi?cantly lower than the lower density groups and middle density groups. Moreover, feed conversion rate(FCR) had a negative correlation with density. Plasma hormone T_3 and GH showed signi?cant decrease with the increase of the stocking density of the experiment. Furthermore, thyroid hormone(T 3), GH(growth hormone) activities were decreased with stocking density increase. However, plasma cortisol, GOT(glutamic oxalacetic transaminase) and GPT(glutamic pyruvic transaminase) activities were increase with stocking density increase. And the stocking density has no ef fects on plasma lysozyme of Atlantic salmon reared in RAS. These investigations would also help devise effcient ways to rear adult Atlantic salmon in China and may, in a way, help spread salmon mariculture in China. 展开更多
关键词 stocking density GROWTH PHYSIOLOGICAL parameters ATLANTIC SALMON RAS
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Permanence and global attractivity of stage-structured predator-prey model with continuous harvesting on predator and impulsive stocking on prey 被引量:1
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作者 焦建军 陈兰荪 +1 位作者 Juan J.Nieto Torres Angela 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2008年第5期653-663,共11页
We investigate a stage-structured delayed predator-prey model with impulsive stocking on prey and continuous harvesting on predator. According to the fact of biological resource management, we improve the assumption o... We investigate a stage-structured delayed predator-prey model with impulsive stocking on prey and continuous harvesting on predator. According to the fact of biological resource management, we improve the assumption of a predator-prey model with stage structure for predator population that each individual predator has the same ability to capture prey. It is assumed that the immature and mature individuals of the predator population are divided by a fixed age, and immature predator population does not have the ability to attach prey. Sufficient conditions are obtained, which guarantee the global attractivity of predator-extinction periodic solution and the permanence of the system. Our results show that the behavior of impulsive stocking on prey plays an important role for the permanence of the system, and provide tactical basis for the biological resource management. Numerical analysis is presented to illuminate the dynamics of the system. 展开更多
关键词 stage-structured impulsive stocking continuous harvesting global attractivity PERMANENCE
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Effect of Stocking Density on Water Quality and(Growth, Body Composition and Plasma Cortisol Content) Performance of Pen-Reared Rainbow Trout(Oncorhynchus mykiss) 被引量:1
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作者 LIU Qun HOU Zhishuai +5 位作者 WEN Haishen LI Jifang HE Feng WANG Jinhuan GUAN Biao WANG Qinglong 《Journal of Ocean University of China》 SCIE CAS 2016年第4期667-675,共9页
The goal of the study was to examine the effect of stocking density on the water quality of culture area, as well as the growth, body composition and cortisol content of rainbow trout(Oncorhynchus mykiss). Pen-reared ... The goal of the study was to examine the effect of stocking density on the water quality of culture area, as well as the growth, body composition and cortisol content of rainbow trout(Oncorhynchus mykiss). Pen-reared trout were stocked in densities of 40, 60, 80 fish individuals m^(-3)(4.6, 6.6, 8.6 kg m^(-3), SD1, SD2 and SD3 groups, respectively) for 300 days. Compared to the water from SD1 and SD2, that from SD3 exhibited significantly higher NH_4^+-N content and COD(chemical-oxygen-demand), and a significant reduction of dissolved oxygen in day 180(40.6 kg m^(-3)). Stocking density was significantly associated with body weight, standard length, VSI(viscerosomatic index), CF(condition factor) and FC(food coefficient) in group SD3, particularly in day 240 and day 300(45 or 49.3 kg m^(-3)). Increased crude fat and decreased crude protein were displayed in high density group when the density reached to 36 kg m^(-3). As a cumulative effect of density-related stress, VSI, CF, FC, moisture, and crude protein content varied over time in each density group(SD1, SD2, and SD3). In summary, trout exhibited a better growth performance in low density(26.3 kg m^(-3)) than those reared in high densities(36 and 45 kg m^(-3)). The results indicate that rainbow trout(114.44 g ± 6.21 g, 19.69 cm ± 0.31 cm) initially stocked in 6.6 or 8.6 kg m^(-3) should be lightened to less than 36 kg m^(-3) after an intensive rearing for 240 days. 展开更多
关键词 rainbow trout stocking density GROWTH CORTISOL body composition
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Lake-Based Nursery Rearing of Nile Tilapia (Oreochromis niloticus) Fingerlings in Nylon Hapas: Effects of Stocking Density on Growth, Survival and Profitability 被引量:1
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作者 Amos Asase Francis Kofi Ewusie Nunoo Felix Yao Klenam Attipoe 《Agricultural Sciences》 2016年第10期660-669,共11页
The inadequate supply of tilapia fingerling is a major limitation to cage culture development in Ghana. Lake-based hapa systems are very efficient in nursing fingerlings although the process can be tricky due to inher... The inadequate supply of tilapia fingerling is a major limitation to cage culture development in Ghana. Lake-based hapa systems are very efficient in nursing fingerlings although the process can be tricky due to inherent effects of stocking densities and environmental factors. This study aimed at assessing the growth, survival and profitability of Nile tilapia (Oreochromis niloticus) fingerlings of the Akosombo strain reared in nine 1 m<sup>3</sup> Lake-based hapas at different densities. Each hapa was stocked with 2.12 ± 0.14 g sex-reversed tilapia fingerlings at varying stocking densities of 400 fish/m<sup>3</sup>, 800 fish/m<sup>3</sup> and 1200 fish/m<sup>3</sup> serving as treatments T1, T2 and T3 respectively. Each treatment was replicated thrice. Bi-weekly samplings were done and water quality parameters were measured. After the experiment, analysis of variance showed significant differences (p 展开更多
关键词 Hapa FINGERLINGS stocking Density TILAPIA
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Stocking density effects on growth and stress response of juvenile turbot(Scophthalmus maximus) reared in land-based recirculating aquaculture system 被引量:1
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作者 LIU Baoliang JIA Rui +3 位作者 ZHAO Kuifeng WANG Guowen LEI Jilin HUANG Bin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第10期31-38,共8页
Stocking density is widely recognized as a critical factor in aquaculture and a potential source of long-term stress.The influence of stocking density on growth and stress response of juvenile turbot(Scophthalmus max... Stocking density is widely recognized as a critical factor in aquaculture and a potential source of long-term stress.The influence of stocking density on growth and stress response of juvenile turbot(Scophthalmus maximus, ~3–75g, initial to final weight) was examined in fish held under low(LD, ~0.21–5.31 kg/m^2, initial to final density),medium(MD, ~0.42–10.81 kg/m^2) and high stocking density(HD, ~0.63–14.27 kg/m^2) for 120 days in a recirculating aquaculture system(RAS). In this trial, the growth curve for weight of juvenile turbot in RAS, all fitted by the Schnute model. No significant difference was found in growth performance among the three densities until at the final sampling(Day 120). The final weight and body weight increase(BWI) in the HD group were significantly lower than in other groups(P〈0.05, weight:(75.83±2.49) g,(75.39±2.08) g,(65.72±2.86) g and BWI:(2 436.12±28.10)%,(2 421.29±4.64)%,(2 097.88±20.99)% in LD, MD and HD groups, respectively). Similarly, the specific growth rate(SGR), feed conversion ratio(FCR) and coefficient of variation for weight(CV_w) were adversely affected by high stocking density(P〈0.05). However, there was no difference in survival and Fulton's condition factor(K) of turbot among the different groups. Physiological analyses demonstrated a clear increase in the plasma cortisol level and an obvious decrease in growth hormone(GH) concentration in the HD group on Day120(P〈0.05). There was no significant effect of stocking density on plasma glucose, Cl– and protein levels. All these findings would provide a reference for selecting the optimal stocking density of juvenile turbot in RAS. 展开更多
关键词 growth performance recirculating aquaculture system Scophthalmus maximus stress physiology stocking density
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Research Progress on Effects of Stocking Density on Performance, Health and Welfare of Duck 被引量:1
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作者 Chaowu YANG Chunlin YU +5 位作者 Zengrong ZHANG Mohan QIU Huarui DU Qingyun LI Xiaosong JIANG Xia XIONG 《Agricultural Biotechnology》 CAS 2020年第4期111-114,119,共5页
Stocking density is an important factor for animal production performance.It appears particularly urgent and important to research systematically on stocking density for the dual restriction of environmental protectio... Stocking density is an important factor for animal production performance.It appears particularly urgent and important to research systematically on stocking density for the dual restriction of environmental protection and animal welfare.This review dealt with the influence of stocking density on ducks'productivity and health through production performance,animal behavior and animal welfare,and analyzed the possible mechanism of high stocking density reducing production performance,resulting in abnormal behavior and stress,causing welfare and health problems.We consider that it might be associated with heat stress,more spatial competition(to gather the food,drinking water,sports area,etc.),as well as the quality deterioration of litter and house air caused by high stocking density.Finally,we put forward some suggestions on the study of stocking density's effects on ducks,and proposed the future work that need to be studied and problems that need to be solved imminently. 展开更多
关键词 Duck Production stocking Density Animal Welfare PERFORMANCE
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Effect of stocking density on performances of juvenile turbot (Scophthalmus maximus) in recirculating aquaculture systems 被引量:6
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作者 李贤 刘鹰 Jean-Paul BLANCHETON 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第3期514-522,共9页
Limited information has been available about the influence of loading density on the performances of Scophthalmus maximus, especially in recirculating aquaculture systems (RAS). In this study, turbot (13.84±2.74g... Limited information has been available about the influence of loading density on the performances of Scophthalmus maximus, especially in recirculating aquaculture systems (RAS). In this study, turbot (13.84±2.74g; average weight±SD) were reared at four different initial densities (low 0.66, medium 1.26, sub-high 2.56, high 4.00 kg/m2 ) for 10 weeks in RAS at 23±1℃. Final densities were 4.67, 7.25, 14.16, and 17.47 kg/m2 , respectively, which translate to 82, 108, 214, and 282 percent coverage of the tank bottom. Density had both negative and independent impacts on growth. The final mean weight, specific growth rate (SGR), and voluntary feed intake significantly decreased and the coefficient of variation (CV) of final body weight increased with increase in stocking density. The medium and sub-high density groups did not differ significantly in SGR, mean weight, CV, food conversion rate (FCR), feed intake, blood parameters, and digestive enzymes. The protease activities of the digestive tract at pH 7, 8.5, 9, and 10 were significantly higher for the highest density group, but tended to be lower (not significantly) at pH 4 and 8.5 for the lowest density group. The intensity of protease activity was inversely related to feed intake at the different densities. Catalase activity was higher (but not significantly) at the highest density, perhaps because high density started to induce an oxidative effect in turbot. In conclusion, turbot can be cultured in RAS at a density of less than 17.47 kg/m2 . With good water quality and no feed limitation, initial density between 1.26 and 2.56 kg/m2 (final: 7.25 and 14.16 kg/m2 ) would not negatively affect the turbot cultured in RAS. For culture at higher density, multi-level feeding devices are suggested to ease feeding competition. 展开更多
关键词 循环水产养殖系统 放养密度 大菱鲆 表演 饲料转化率 蛋白酶活性 循环水养殖系统 自由采食量
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Effect of Alum-Amended Litter and Stocking Density on Ammonia Release and Footpad and Hock Dermatitis of Broilers
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作者 ZHANG Hong-fang JIAO Hong-chao SONG Zhi-gang LIN Hai 《Agricultural Sciences in China》 CAS CSCD 2011年第5期777-785,共9页
Two experiments were conducted to evaluate the effect of alum on ammonia emission,live performance,and health of broilers.In experiment 1,the effect of alum (0,2,and 4%) supplementation on the emission of ammonia wa... Two experiments were conducted to evaluate the effect of alum on ammonia emission,live performance,and health of broilers.In experiment 1,the effect of alum (0,2,and 4%) supplementation on the emission of ammonia was measured.The effects of alum-treated litter and stocking density (12,16,and 20 birds m-2) on the live performance and incidence of footpad and hock dermatitis were investigated in experiment 2.Alum supplementation in chicken excreta significantly decreased pH from 8.06 to 5.27 and 3.62 by 2 and 4% alum treatments,respectively.Ammonia emission rate was reduced 73.0 and 75.8% by 2 and 4% alum treatments,respectively.The suppressed litter urease activity was detected in 4% alum treatment.Alum-amended litter (1 kg m-2) decreased atmosphere ammonia concentrations by 30% in broiler house.Alum-amended litter maintained a lower pH until 35 d of age.Body weight (BW) gain was decreased by alum treatment in the period of 4-7 wk of age.Higher stocking density (20 birds m-2) increased BW gain in the first 3 wk of age but decreased BW gain during the period of 4-7 wk of age.Neither alum nor stocking density treatments had a significant effect on feed intake and feed efficiency.Alum-treated litter had no detrimental effect on the development of footpad and hock burns.In contrast,high stocking density (20 bird m-2) increased the incidence of footpad and hock lesion.The result suggests that the decreased litter pH and suppressed bacterial urease activity by alum treatment is responsible for the decreased ammonia emission.At high stocking density,the increased litter moisture content should be responsible,at least partially,for the development of footpad and hock lesions. 展开更多
关键词 AMMONIA stocking density LITTER ALUM BROILERS
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REDUCED GROWTH IN HYBRID TILAPIA (OREOCHROMIS MOSSAMBICUS×O. NILOTICUS) AT INTERMEDIATE STOCKING DENSITY 被引量:2
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作者 王岩 崔奕波 +1 位作者 杨云霞 蔡发盛 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2002年第4期344-347,共4页
Hybrid tilapia were reared at densities of 1, 5 or 10 fish per tank for four weeks. Mortality was 0 at 1 and 10 fish per tank, but was 25% at 5 fish per tank. Specific growth rate was highest at 1 fish per tank, and l... Hybrid tilapia were reared at densities of 1, 5 or 10 fish per tank for four weeks. Mortality was 0 at 1 and 10 fish per tank, but was 25% at 5 fish per tank. Specific growth rate was highest at 1 fish per tank, and lowest at 5 fish per tank. The lower growth rate at the intermediate stocking density was associated with reduced feed efficiency, but there was no reduction in feed intake or digestibility. The results suggested increased metabolic cost caused by aggressive behaviour at intermediate stocking density, which can be suppressed by a further increase in density. 展开更多
关键词 罗非鱼 杂交种 混养 死亡率 养殖密度 生长速率
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Effects of osmotic pressure, temperature and stocking density on survival and sexual reproduction of Craspedacusta sowerbii
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作者 Yuan-Wei ZHANG Xiao-Fu PAN +3 位作者 Xiao-Ai WANG Wan-Sheng JIANG Qian LIU Jun-Xing YANG 《Zoological Research》 CAS CSCD 2016年第2期90-95,共6页
The effects of osmotic pressure, temperature and stocking density on medusae survival of Craspedacusta sowerbii were examined. The medusae were shown to be sensitive to the variations of osmotic pressure. And the surv... The effects of osmotic pressure, temperature and stocking density on medusae survival of Craspedacusta sowerbii were examined. The medusae were shown to be sensitive to the variations of osmotic pressure. And the survival time was 〈90 h at 34 mOsm/L and it declined rapidly with rising osmotic pressure. The peak survival time of 〉200 h was recorded at 0.2 mOsm/L. Comparing with 27℃ and 32 ℃ treatments, 23 ℃ treatment yielded lower activities at a range of 8-13/min. However, there was a longer survival time. A non-linear relationship existed between survival time and stocking density. Lower density resulted in larger body size. And sexual reproduction resumed after breeding for 〉22 days. Newly-formed polyps and medusae appeared subsequently but only in the higher-density groups of 10, 14 and 18 ind./L. It suggested that the number of newly-formed polyps and medusae was highly dependent on stocking density. That is, a higher stocking density produced more organisms. However, newly-formed medusae died within one month and none grew a diameter of 〉5 mm. 展开更多
关键词 Craspedacusta sowerbfi Osmotic pressure TEMPERATURE stocking density
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