A potential 4.2 V cathode material LiVPO4F for lithium batteries was prepared by two-step reaction method based on a carbon-thermal reduction (CTR) process. Firstly, V2O5, NH4H2PO4 and acetylene black are reacted un...A potential 4.2 V cathode material LiVPO4F for lithium batteries was prepared by two-step reaction method based on a carbon-thermal reduction (CTR) process. Firstly, V2O5, NH4H2PO4 and acetylene black are reacted under an Ar atmosphere to yield VPO4. The transition-metal reduction is facilitated by the CTR based on C→CO transition. These CTR conditions favor stabilization of the vanadium as V^3+ as well as leaving residual carbon, which is useful in the subsequent electrode processing. Secondly, VPO4 reacts with ElF to yield LiVPO4F product. The property of the LiVPO4F was investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and electrochemical measurement. XRD studies show that LiVPO4F synthesized has triclinic structure(space group p I ), isostructural with the naturally occurring mineral tavorite, EiFePO4-OH. SEM image exhibits that the particle size is about 2μm together with homogenous distribution. Electrochemical test shows that the initial discharge capacity of LiVPO4F powder is 119 mA·h/g at the rate of 0.2C with an average discharge voltage of 4.2V (vs Ei/Li^+), and the capacity retains 89 mA·h/g after 30 cycles.展开更多
This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture of Litopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to ne...This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture of Litopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to near to commercial diet with about 40% protein and 7.5% lipid. Fish meal was replaced by 0, 30%, 40%, 50%, 60%, 70% and 100% of PBM (diets 1-7). The diet with 100% fish meal was used as a control (diet 1). Post-larvae were reared in an indoor semi-closed re-circulating system. Each dietary treatment was tested in 4 replicate tanks (260 L) of 40 shrimp, arranged in a completely randomized design. The shrimps were hand-fed for three times a day to near-satiation (0700, 1200 and 1800) for 60 d. Percentage weight gain, survival, feed conversion ratio (FCR), protein efficiency ratio (PER) and body composition of shrimps were measured. There were no significant differences (P>0.05) in growth performance among shrimps fed diets 1-5 (0-60% fish meal replacement). However, shrimps fed diet 7 (100% fish meal replacement) had significantly lower (P<0.05) growth than those fed diets 1-5 (0-60% fish meal replacement). Shrimp fed diets 2-4 (30%-50% fish meal replacement) showed significantly higher growth than those fed diets 6 and 7 (70% and 100% fish meal replacement, respectively). Survival ranged from 94.7% to 100.0% and did not differ significantly (P>0.05) among different experimental diets. No differences in body composition were found among shrimps fed different diets. These results showed that up to 70% of fish meal protein can be replaced by PBM without adversely affecting the growth, survival, FCR, PER and body composition of Litopenaeus vannamei.展开更多
Dietary leucine requirement for juvenile large yellow croaker, Pseudosciaena crocea Richardson 1846 (initial body weight 6.0 g±0.1 g) was determined using dose-response method.Six isonitogenous (crude protein 43%...Dietary leucine requirement for juvenile large yellow croaker, Pseudosciaena crocea Richardson 1846 (initial body weight 6.0 g±0.1 g) was determined using dose-response method.Six isonitogenous (crude protein 43%) and isoenergetic (19 kJ g-1) practical diets containing six levels of leucine (Diets 1-6) ranging from 1.23% to 4.80% (dry matter) were made at about 0.7% increment of leucine.Equal amino acid nitrogen was maintained by replacing leucine with glutamic acid.Triplicate groups of 60 individuals were fed to apparent satiation by hand twice daily (05:00 and 17:30).The water temperature was 26-32℃, salinity 26-30 and dissolved oxygen approximately 7 mg L-1 during the experimental period.Final weight (FW) of large yellow croaker initially increased with increasing level of dietary leucine but then decreased at further higher level of leucine.The highest FW was obtained in fish fed diet with 3.30% Leucine (Diet 4).FW of fish fed the diet with 4.80% Leucine (Diet 6) was significantly lower than those fed Diet 4.However, no significant differences were observed between the other dietary treatments.Feed efficiency (FE) and whole body composition were independent of dietary leucine contents (P>0.05).The results indicated that leucine was essential for growth of juvenile large yellow croaker.On the basis of FW, the optimum dietary leucine requirement for juvenile large yellow croaker was estimated to be 2.92% of dry matter (6.79% of dietary protein).展开更多
Dehong Dai and Jingpo Autonomous Prefecture is located in western Yunnan.Due to special natural environment and multi-ethic settlement,the unique cultural environment and folk customs have been formed in this area.Thi...Dehong Dai and Jingpo Autonomous Prefecture is located in western Yunnan.Due to special natural environment and multi-ethic settlement,the unique cultural environment and folk customs have been formed in this area.This paper investigated on and collated the traditional cultures and edible spices in native minorities of Dehong.In addition,the special spices those form the special flavor and their application in food with ethic characteristics were proposed.展开更多
Juvenile silver pomfret, Pampus argenteus, was grown in culture tanks for 9 weeks on four different diets, and their effects on fish growth, digestive enzyme activity, and body composition were assessed. The feeding r...Juvenile silver pomfret, Pampus argenteus, was grown in culture tanks for 9 weeks on four different diets, and their effects on fish growth, digestive enzyme activity, and body composition were assessed. The feeding regime was as follows: Diet 1: fish meat; Diet 2: fish meat+artificial feed; Diet 3: fish meat+artificial feed+Agamaki clam meat; Diet 4: fish meat+artificial feed+Agamaki clam+copepods. The greatest weight gain was associated with Diet 4, while the lowest weight gain was associated with Diet 1. No significant difference was observed in weight gain between fish receiving Diet 2 and Diet 3. Specific growth rate followed similar trends as weight gain. The feed conversion ratio (FCR) of fish fed Diet 1 was significantly higher than the other fish groups, but no significant differences were observed in FCRs of fish fed Diet 2, Diet 3 or Diet 4. There was also no significant difference in the hepatosomatic index (HSI) between the four diets. For fish that received Diets 2-4, containing artificial feed, higher protease activities were detected. A higher lipid content of the experimental diets also significantly increased lipase activities and body lipid content. No significant differences in amylase activity or body protein content were found between Diets 1-4. In conclusion, a variety of food components, including copepods and artificial feed, in the diet of silver pomfret significantly increased digestive enzyme activity and could improve growth performance.展开更多
Problem about adolescent drinking has accelerated. Although the alcohol advertisements are restricted by Thai law, nevertheless the alcohol manufactures could still find their way to convey the message about their pro...Problem about adolescent drinking has accelerated. Although the alcohol advertisements are restricted by Thai law, nevertheless the alcohol manufactures could still find their way to convey the message about their products to their consumers, including the adolescents in the school system through several marketing communication tactics. To this study, investigated opinion of Thai teens on alcohol use specific to.. (1) types of alcoholic beverages preferred; (2) reason at first alcohol use; (3) future drinking intention; and (4) perceptions toward alcohol marketing communication. The cross-sectional survey was conducted on 5184 students from grades 4th-12th and vocational school in seven regions of Thailand. The data from questionnaires were analyzed using simple descriptive statistic, frequency distribution, and percentages. Those teens reported to start drinking beer because of wanting to experiment with alcohol (41.3%), to celebrate in special occasion (29.2%), and due to friends involved (15.7%). Majority of teens in this study (〉 80%) disagree or strongly disagree with persuasive message of alcohol advertised through several media channels. Most of the samples have good media literacy, know the intention of the marketing communication of the alcohol manufacturers, and could not be persuaded easily. The results required further evaluation for influence of alcohol marketing communication on students' alcohol expectancy and alcohol use for proper policy recommendation and management.展开更多
A feeding experiment was conducted to investigate the effect of Bacillus subtilis bacterium and its suitable level on survival and growth rate of juvenile Macrobrachium rosenbergii (de Man) during March 28 to May 28...A feeding experiment was conducted to investigate the effect of Bacillus subtilis bacterium and its suitable level on survival and growth rate of juvenile Macrobrachium rosenbergii (de Man) during March 28 to May 28, 2010. A B. subtilis bacterium isolated from chicken intestine was added to commercial prawn feed as a probiotic. Six diets were prepared by soaking prawn feed into the B. subtilis to achieve 10^10, 10^9, 10^8, 10^7 and 106 levels with a non-treated control. After 60 days, the prawns fed diet at level 10^8 showed a higher mean weight gain (593.45 g) or 170.29% increase in growth over control. The mean weight gain showed a decreasing trend as the B. subtilis level decreased from 10^8 to 10^6 and the B. subtilis level increased from 10^8 to 10^10 in the diets. There were significant differences (P 〈 0.05) in weight gain, feed intake, daily growth and feed conversion ratio (FCR) among treated and controlled groups. There were significant differences (P 〈 0.05) among treatments and control in survival rate but no significant differences (P 〉 0.05) in water quality and biochemical composition among treated and controlled groups. Clearly, treated with B. subtilis appeared to enhance growth and survival of M. rosenbergii. It was concluded that the tested strain may be a promising probiotics for M. rosenbergii at a level of 10^8 B. subtilis into the prawn feed.展开更多
The libraries, especially the university libraries, are the important gathering places of the human cultural knowledge and the inheritance, which usually house some important and rare historical literature books and m...The libraries, especially the university libraries, are the important gathering places of the human cultural knowledge and the inheritance, which usually house some important and rare historical literature books and materials. Especially the local university libraries in the minority agglomeration regions collect the cultural resources with the local ethnic characteristics, so the local university libraries should have the better geographical advantages and the advantages of the subject resources to give full play to the unique functions and values to study and inherit the local cultural protection.展开更多
The role of geomorphic habitat type, drift cell scale, and geographic scale in defining fish use of nearshore habitats is poorly known, particularly for Pacific salmon and their prey. In this study, key areas of nears...The role of geomorphic habitat type, drift cell scale, and geographic scale in defining fish use of nearshore habitats is poorly known, particularly for Pacific salmon and their prey. In this study, key areas of nearshore habitat in central and western Strait of Juan de Fuca were categorized by geomorphic habitat type and assessed for fish use within a degraded (Elwha) and intact comparative drift cells over a one year period. Juvenile Chinook and coho salmon were also sampled for genetic analysis to define regional dispersal patterns. Key findings are: (1) Ecological function of the area's nearshore is complex, with very strong seasonal variation in fish use both within and across GMHT (geomorphic habitat type); (2) GMHT link to nearshore function for fish use differs depending on the fish species and time of year. Surf smelt and sand lance were the most abundant. And they were seasonally used embayed, spit, and bluff shorelines more than lower rivers. Juvenile Chinook, coho, and chum salmon occurred in much lower density than forage fish species, and used lower rivers more than other GMHTs; (3) When GMHTs were combined and analyzed at the drift cell scale, the degraded drift cell had different ecological patterns than the intact drift cell; (4) Cross regional juvenile fish use of nearshore is an important component of habitat use: juvenile Chinook and coho from as far away as the Columbia River Oregon and Klamath River California utilize central Strait of Juan de Fuca shorelines. Forage fish species may do so as well. Drift cell and cross regional scales are therefore most important for accurately defining nearshore ecological function, management, and restoration actions.展开更多
Effect of salinity on survival,feeding behavior and growth of juvenile swimming crab P ortunus trituberculatus was investigated under 5 salinity levels of 5,10,20,30 and 40. The results show that the crab juveniles fe...Effect of salinity on survival,feeding behavior and growth of juvenile swimming crab P ortunus trituberculatus was investigated under 5 salinity levels of 5,10,20,30 and 40. The results show that the crab juveniles fed 2 or 3 times at the salinity 20 and 30,each lasted for about 25 minutes,for a total feeding time of 73.2±22.65 minutes per day. At these salinities,there were significantly higher in the frequency of feeding and in total feeding time than those at lower salinities of 5 and 10. All crab juveniles moulted when reared at a salinity of 20 during the 5 days duration of the experiment,which is significantly higher than those at other salinities. All juveniles survived at salinity 20,and the survivorship was not significantly different from that at 30,but was signif icantly higher than those at other salinities. The crab juveniles reared at a salinity of 20 had the highest value of food ration of 0.190 8±0.011 3 g/g BW,average body weight gain of 0.796±0.128 g,gain rate of 87%–96%,and food conversion ratio of 1.20±0.09. There was no significant difference in the values found between 20 and 30 but these values were significantly lower than that at the other salinities( P> 0.05). Highest activities of digestive enzymes(Amylase,Protease,Lipase) and lowest activities of protective enzymes(SOD,PO,CAT) were also obtained on crab juveniles reared at salinity of 20.展开更多
The aim of the present study was to develop a formulated feed for improving skin pigmentation and growth performance of koi carp juveniles. Two experiments were conducted for determination of an optimal dietary astaxa...The aim of the present study was to develop a formulated feed for improving skin pigmentation and growth performance of koi carp juveniles. Two experiments were conducted for determination of an optimal dietary astaxanthin and FM (fish meal) ration for koi carp juveniles. In the first experiment, three isonitrogenous and isoenergetic dietary treatments were designed with three different levels of astaxanthin consisted of 60, 80 and 100 mg/kg and a commercial feed served as a control. For the second experiment, four isonitrogenous and isoenergetic dietary treatments were formulated with graded inclusions of dietary FM replaced from 0% to 60% at 20% increments by SM (soybean meal), PBM (poultry by-product meal), and a CD (control diet). Obtained results demonstrated that skin pigmentation of koi carp juveniles fed the diet containing 80 mg/kg astaxanthin, 36.02% protein, 7.78% lipid, 4.20 Kcal/g GE (gross energy) were more better than those at the diet with lower estaxanthin content and commercial diet. Moreover, the highest growth and feed utilization of fish were observed at this diet with WG (weight gain), SGR (specific growth rate) and FCR (feed conversion ratio) were 121.80%, 0.95 (%/day) and 1.6, respectively.展开更多
基金Project(50302016) supported by the National Natural Science Foundation of China
文摘A potential 4.2 V cathode material LiVPO4F for lithium batteries was prepared by two-step reaction method based on a carbon-thermal reduction (CTR) process. Firstly, V2O5, NH4H2PO4 and acetylene black are reacted under an Ar atmosphere to yield VPO4. The transition-metal reduction is facilitated by the CTR based on C→CO transition. These CTR conditions favor stabilization of the vanadium as V^3+ as well as leaving residual carbon, which is useful in the subsequent electrode processing. Secondly, VPO4 reacts with ElF to yield LiVPO4F product. The property of the LiVPO4F was investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and electrochemical measurement. XRD studies show that LiVPO4F synthesized has triclinic structure(space group p I ), isostructural with the naturally occurring mineral tavorite, EiFePO4-OH. SEM image exhibits that the particle size is about 2μm together with homogenous distribution. Electrochemical test shows that the initial discharge capacity of LiVPO4F powder is 119 mA·h/g at the rate of 0.2C with an average discharge voltage of 4.2V (vs Ei/Li^+), and the capacity retains 89 mA·h/g after 30 cycles.
基金financial support by grant No. 30871928 from the National Natural Science Foun-dation of China (NSFC)
文摘This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture of Litopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to near to commercial diet with about 40% protein and 7.5% lipid. Fish meal was replaced by 0, 30%, 40%, 50%, 60%, 70% and 100% of PBM (diets 1-7). The diet with 100% fish meal was used as a control (diet 1). Post-larvae were reared in an indoor semi-closed re-circulating system. Each dietary treatment was tested in 4 replicate tanks (260 L) of 40 shrimp, arranged in a completely randomized design. The shrimps were hand-fed for three times a day to near-satiation (0700, 1200 and 1800) for 60 d. Percentage weight gain, survival, feed conversion ratio (FCR), protein efficiency ratio (PER) and body composition of shrimps were measured. There were no significant differences (P>0.05) in growth performance among shrimps fed diets 1-5 (0-60% fish meal replacement). However, shrimps fed diet 7 (100% fish meal replacement) had significantly lower (P<0.05) growth than those fed diets 1-5 (0-60% fish meal replacement). Shrimp fed diets 2-4 (30%-50% fish meal replacement) showed significantly higher growth than those fed diets 6 and 7 (70% and 100% fish meal replacement, respectively). Survival ranged from 94.7% to 100.0% and did not differ significantly (P>0.05) among different experimental diets. No differences in body composition were found among shrimps fed different diets. These results showed that up to 70% of fish meal protein can be replaced by PBM without adversely affecting the growth, survival, FCR, PER and body composition of Litopenaeus vannamei.
基金supported by the National Key Technologies Research and Development Program for the 10th Five-year Plan of China (Grant No.2004BA526B-06)Program for New Century Excellent Talents in University (NCET-07-0776)
文摘Dietary leucine requirement for juvenile large yellow croaker, Pseudosciaena crocea Richardson 1846 (initial body weight 6.0 g±0.1 g) was determined using dose-response method.Six isonitogenous (crude protein 43%) and isoenergetic (19 kJ g-1) practical diets containing six levels of leucine (Diets 1-6) ranging from 1.23% to 4.80% (dry matter) were made at about 0.7% increment of leucine.Equal amino acid nitrogen was maintained by replacing leucine with glutamic acid.Triplicate groups of 60 individuals were fed to apparent satiation by hand twice daily (05:00 and 17:30).The water temperature was 26-32℃, salinity 26-30 and dissolved oxygen approximately 7 mg L-1 during the experimental period.Final weight (FW) of large yellow croaker initially increased with increasing level of dietary leucine but then decreased at further higher level of leucine.The highest FW was obtained in fish fed diet with 3.30% Leucine (Diet 4).FW of fish fed the diet with 4.80% Leucine (Diet 6) was significantly lower than those fed Diet 4.However, no significant differences were observed between the other dietary treatments.Feed efficiency (FE) and whole body composition were independent of dietary leucine contents (P>0.05).The results indicated that leucine was essential for growth of juvenile large yellow croaker.On the basis of FW, the optimum dietary leucine requirement for juvenile large yellow croaker was estimated to be 2.92% of dry matter (6.79% of dietary protein).
文摘Dehong Dai and Jingpo Autonomous Prefecture is located in western Yunnan.Due to special natural environment and multi-ethic settlement,the unique cultural environment and folk customs have been formed in this area.This paper investigated on and collated the traditional cultures and edible spices in native minorities of Dehong.In addition,the special spices those form the special flavor and their application in food with ethic characteristics were proposed.
基金Supported by the National Key Technology Research and Development Program during the Twelfth Five-Year Plan Period(No.2011BAD13B01)the Central Nonprofit Basic Scientific Research Project for the Scientific Research Institutes of China(No.East-2011M09)the Research Project Commissioned by the Shanghai Agricultural Commission(No.2007-4-1)
文摘Juvenile silver pomfret, Pampus argenteus, was grown in culture tanks for 9 weeks on four different diets, and their effects on fish growth, digestive enzyme activity, and body composition were assessed. The feeding regime was as follows: Diet 1: fish meat; Diet 2: fish meat+artificial feed; Diet 3: fish meat+artificial feed+Agamaki clam meat; Diet 4: fish meat+artificial feed+Agamaki clam+copepods. The greatest weight gain was associated with Diet 4, while the lowest weight gain was associated with Diet 1. No significant difference was observed in weight gain between fish receiving Diet 2 and Diet 3. Specific growth rate followed similar trends as weight gain. The feed conversion ratio (FCR) of fish fed Diet 1 was significantly higher than the other fish groups, but no significant differences were observed in FCRs of fish fed Diet 2, Diet 3 or Diet 4. There was also no significant difference in the hepatosomatic index (HSI) between the four diets. For fish that received Diets 2-4, containing artificial feed, higher protease activities were detected. A higher lipid content of the experimental diets also significantly increased lipase activities and body lipid content. No significant differences in amylase activity or body protein content were found between Diets 1-4. In conclusion, a variety of food components, including copepods and artificial feed, in the diet of silver pomfret significantly increased digestive enzyme activity and could improve growth performance.
文摘Problem about adolescent drinking has accelerated. Although the alcohol advertisements are restricted by Thai law, nevertheless the alcohol manufactures could still find their way to convey the message about their products to their consumers, including the adolescents in the school system through several marketing communication tactics. To this study, investigated opinion of Thai teens on alcohol use specific to.. (1) types of alcoholic beverages preferred; (2) reason at first alcohol use; (3) future drinking intention; and (4) perceptions toward alcohol marketing communication. The cross-sectional survey was conducted on 5184 students from grades 4th-12th and vocational school in seven regions of Thailand. The data from questionnaires were analyzed using simple descriptive statistic, frequency distribution, and percentages. Those teens reported to start drinking beer because of wanting to experiment with alcohol (41.3%), to celebrate in special occasion (29.2%), and due to friends involved (15.7%). Majority of teens in this study (〉 80%) disagree or strongly disagree with persuasive message of alcohol advertised through several media channels. Most of the samples have good media literacy, know the intention of the marketing communication of the alcohol manufacturers, and could not be persuaded easily. The results required further evaluation for influence of alcohol marketing communication on students' alcohol expectancy and alcohol use for proper policy recommendation and management.
文摘A feeding experiment was conducted to investigate the effect of Bacillus subtilis bacterium and its suitable level on survival and growth rate of juvenile Macrobrachium rosenbergii (de Man) during March 28 to May 28, 2010. A B. subtilis bacterium isolated from chicken intestine was added to commercial prawn feed as a probiotic. Six diets were prepared by soaking prawn feed into the B. subtilis to achieve 10^10, 10^9, 10^8, 10^7 and 106 levels with a non-treated control. After 60 days, the prawns fed diet at level 10^8 showed a higher mean weight gain (593.45 g) or 170.29% increase in growth over control. The mean weight gain showed a decreasing trend as the B. subtilis level decreased from 10^8 to 10^6 and the B. subtilis level increased from 10^8 to 10^10 in the diets. There were significant differences (P 〈 0.05) in weight gain, feed intake, daily growth and feed conversion ratio (FCR) among treated and controlled groups. There were significant differences (P 〈 0.05) among treatments and control in survival rate but no significant differences (P 〉 0.05) in water quality and biochemical composition among treated and controlled groups. Clearly, treated with B. subtilis appeared to enhance growth and survival of M. rosenbergii. It was concluded that the tested strain may be a promising probiotics for M. rosenbergii at a level of 10^8 B. subtilis into the prawn feed.
文摘The libraries, especially the university libraries, are the important gathering places of the human cultural knowledge and the inheritance, which usually house some important and rare historical literature books and materials. Especially the local university libraries in the minority agglomeration regions collect the cultural resources with the local ethnic characteristics, so the local university libraries should have the better geographical advantages and the advantages of the subject resources to give full play to the unique functions and values to study and inherit the local cultural protection.
文摘The role of geomorphic habitat type, drift cell scale, and geographic scale in defining fish use of nearshore habitats is poorly known, particularly for Pacific salmon and their prey. In this study, key areas of nearshore habitat in central and western Strait of Juan de Fuca were categorized by geomorphic habitat type and assessed for fish use within a degraded (Elwha) and intact comparative drift cells over a one year period. Juvenile Chinook and coho salmon were also sampled for genetic analysis to define regional dispersal patterns. Key findings are: (1) Ecological function of the area's nearshore is complex, with very strong seasonal variation in fish use both within and across GMHT (geomorphic habitat type); (2) GMHT link to nearshore function for fish use differs depending on the fish species and time of year. Surf smelt and sand lance were the most abundant. And they were seasonally used embayed, spit, and bluff shorelines more than lower rivers. Juvenile Chinook, coho, and chum salmon occurred in much lower density than forage fish species, and used lower rivers more than other GMHTs; (3) When GMHTs were combined and analyzed at the drift cell scale, the degraded drift cell had different ecological patterns than the intact drift cell; (4) Cross regional juvenile fish use of nearshore is an important component of habitat use: juvenile Chinook and coho from as far away as the Columbia River Oregon and Klamath River California utilize central Strait of Juan de Fuca shorelines. Forage fish species may do so as well. Drift cell and cross regional scales are therefore most important for accurately defining nearshore ecological function, management, and restoration actions.
基金Supported by the Science and Technology Innovation Team of Marine Crab Industry in Ningbo City(No.2011B81003)the National Natural Science Foundation of China(No.41276123)+2 种基金the National Spark Plan Program of China(No.2012GA701048)the Key Project of Ministry of Education,Science and Technology(No.212070)the K C Wong Magana Fund in Ningbo University
文摘Effect of salinity on survival,feeding behavior and growth of juvenile swimming crab P ortunus trituberculatus was investigated under 5 salinity levels of 5,10,20,30 and 40. The results show that the crab juveniles fed 2 or 3 times at the salinity 20 and 30,each lasted for about 25 minutes,for a total feeding time of 73.2±22.65 minutes per day. At these salinities,there were significantly higher in the frequency of feeding and in total feeding time than those at lower salinities of 5 and 10. All crab juveniles moulted when reared at a salinity of 20 during the 5 days duration of the experiment,which is significantly higher than those at other salinities. All juveniles survived at salinity 20,and the survivorship was not significantly different from that at 30,but was signif icantly higher than those at other salinities. The crab juveniles reared at a salinity of 20 had the highest value of food ration of 0.190 8±0.011 3 g/g BW,average body weight gain of 0.796±0.128 g,gain rate of 87%–96%,and food conversion ratio of 1.20±0.09. There was no significant difference in the values found between 20 and 30 but these values were significantly lower than that at the other salinities( P> 0.05). Highest activities of digestive enzymes(Amylase,Protease,Lipase) and lowest activities of protective enzymes(SOD,PO,CAT) were also obtained on crab juveniles reared at salinity of 20.
文摘The aim of the present study was to develop a formulated feed for improving skin pigmentation and growth performance of koi carp juveniles. Two experiments were conducted for determination of an optimal dietary astaxanthin and FM (fish meal) ration for koi carp juveniles. In the first experiment, three isonitrogenous and isoenergetic dietary treatments were designed with three different levels of astaxanthin consisted of 60, 80 and 100 mg/kg and a commercial feed served as a control. For the second experiment, four isonitrogenous and isoenergetic dietary treatments were formulated with graded inclusions of dietary FM replaced from 0% to 60% at 20% increments by SM (soybean meal), PBM (poultry by-product meal), and a CD (control diet). Obtained results demonstrated that skin pigmentation of koi carp juveniles fed the diet containing 80 mg/kg astaxanthin, 36.02% protein, 7.78% lipid, 4.20 Kcal/g GE (gross energy) were more better than those at the diet with lower estaxanthin content and commercial diet. Moreover, the highest growth and feed utilization of fish were observed at this diet with WG (weight gain), SGR (specific growth rate) and FCR (feed conversion ratio) were 121.80%, 0.95 (%/day) and 1.6, respectively.