The present study was to investigate the effects of feeding time on growth of the Chinese soft-shelled turtle. The experiment was carried out with a photoperiod of 12L （light）： 12D （dark） with lights on at 06：00...The present study was to investigate the effects of feeding time on growth of the Chinese soft-shelled turtle. The experiment was carried out with a photoperiod of 12L （light）： 12D （dark） with lights on at 06：00 and off at 18：00. Turtles were maintained at a temperature of 32 - 0.2 ℃ in tanks throughout the length of the experiment. The turtles in group 1 to group 6 were fed respectively at 00：00, 04：00, 08：00, 12：00, 16：00 and 20：00 with 60 turtles each （Initial body weight 88.27 - 0.09 g）. Acrophases of postprandial RNA/DNA ratio in liver in each group was shown between 5h and 7h after feeding. A positive linear correlation could be seen between specific growth rate （SGR） and RNA/ DNA：SGR=t.1586RNA/DNA-0.7097 （r = 0.9328, P = 0.0066）. The results indicated that the values at the acrophases of about 6h after feeding might be used as an instantaneous growth index in the Chinese soft-shelled turtle. The turtles in group 1 grew better than group 3, group 4, group 5, group 6, because they ate more, but they ate more and grew slower than group 2, whose feed conversion rate was also higher. Meanwhile, the SGR and feeding rate of turtles fed at 12：00 were the lowest from the six groups （P 〈 0.05）. Turtles fed in group 1, group 2 and group 6 developed more heavy final body weight （FBW）, higher feeding rate and SGR than the other three groups. This probably suggested that turtles fed in scotophase grew better than that fed at photophase in total.展开更多
Shifting the feeding time for fish from daytime to nighttime could alter their digestive behavior, disturb their metabolism, and may af fect immune-related genes. This study aimed to clone complement component C7 and ...Shifting the feeding time for fish from daytime to nighttime could alter their digestive behavior, disturb their metabolism, and may af fect immune-related genes. This study aimed to clone complement component C7 and analyze the different expression of C7 mRNA in fish fed during either the day or at night and then challenged with Aeromonas hydrophila infection. The P v-C7 cDNA of Pelteobagrus vachellii contained 2 647 bp with an open reading frame encoding a protein of 818 amino acids. Multiple sequences analysis indicated that P v-C7 included eight domains, which was similar to results for other species. Quantitative PCR analysis showed that P v-C7 was mainly expressed in the liver, spleen, intestine and head kidney tissues of healthy P. vachellii. Quantitative PCR analysis showed that C7 mRNA transcript in the liver, spleen and head kidney also increased significantly when the fish were fed at nighttime(20:00). In addition, the expression of Pv-C7 mRNA significantly increased with A. hydrophila challenge in the liver(48–96 h), spleen and head kidney(12–96 h) tissues of P. vachellii. Pv-C7 mRNA expression of the fish fed at nighttime showed significant higher than that in the fish fed at day time at 12–48 h in head kidney and 12–24 h in spleen. This study indicates that altering the feeding time from daytime to nighttime could increase P v-C7 mRNA expression, and feeding time may af fect the immune response involving C7.展开更多
由于传统淡水鱼池塘养殖存在废物过量堆积、水体污染严重等问题,以及中国对水产品需求的增加,工厂化循环水养殖、集装箱、圈养模式等高质量、高产量、集约化的新型淡水鱼养殖模式逐渐得到应用。针对新型淡水鱼养殖模式存在投饲劳动强度...由于传统淡水鱼池塘养殖存在废物过量堆积、水体污染严重等问题,以及中国对水产品需求的增加,工厂化循环水养殖、集装箱、圈养模式等高质量、高产量、集约化的新型淡水鱼养殖模式逐渐得到应用。针对新型淡水鱼养殖模式存在投饲劳动强度大、自动化程度低等问题,设计了一款气送式自动投饲系统,实现了定向、定时和定量投饲功能。设计了特定的四通装置和三通装置以保证饲料的定向输送;基于计算流体力学和离散单元法(Computational fluid dynamics-Discrete element method,CFD-DEM)耦合技术,初步确定了满足投饲要求的投饲速度并由此确定了风机型号;开发了以Arduino Mega 2560单片机为核心处理器的投饲控制系统,通过时钟模块实时获取当前时间信息,通过称量传感器实时获取料仓内物料质量信息,通过蓝牙传输预计投饲区域、投饲时间和投饲质量,从而实现定向定时定量投饲;最后试制样机并进行了性能试验,两种工况下投饲的实际投饲距离与仿真结果误差分别为5.74%和9.54%,定向、定时和定量投饲可以准确实现,控制系统响应时间小于1 s,定量投饲最大误差为5.37%。研究结果表明,自动投饲系统结构可靠、控制系统精度较高,满足自动投饲要求。展开更多
基金supported by the National Natural Science Foundation of China (No.31172085)
文摘The present study was to investigate the effects of feeding time on growth of the Chinese soft-shelled turtle. The experiment was carried out with a photoperiod of 12L （light）： 12D （dark） with lights on at 06：00 and off at 18：00. Turtles were maintained at a temperature of 32 - 0.2 ℃ in tanks throughout the length of the experiment. The turtles in group 1 to group 6 were fed respectively at 00：00, 04：00, 08：00, 12：00, 16：00 and 20：00 with 60 turtles each （Initial body weight 88.27 - 0.09 g）. Acrophases of postprandial RNA/DNA ratio in liver in each group was shown between 5h and 7h after feeding. A positive linear correlation could be seen between specific growth rate （SGR） and RNA/ DNA：SGR=t.1586RNA/DNA-0.7097 （r = 0.9328, P = 0.0066）. The results indicated that the values at the acrophases of about 6h after feeding might be used as an instantaneous growth index in the Chinese soft-shelled turtle. The turtles in group 1 grew better than group 3, group 4, group 5, group 6, because they ate more, but they ate more and grew slower than group 2, whose feed conversion rate was also higher. Meanwhile, the SGR and feeding rate of turtles fed at 12：00 were the lowest from the six groups （P 〈 0.05）. Turtles fed in group 1, group 2 and group 6 developed more heavy final body weight （FBW）, higher feeding rate and SGR than the other three groups. This probably suggested that turtles fed in scotophase grew better than that fed at photophase in total.
基金Supported by the National Natural Science Foundation of China(No.31402305)the Natural Science Foundation of Sichuan Province(No.2017JY0161)the Educational Commission of Sichuan Province of China(No.14ZA0249)
文摘Shifting the feeding time for fish from daytime to nighttime could alter their digestive behavior, disturb their metabolism, and may af fect immune-related genes. This study aimed to clone complement component C7 and analyze the different expression of C7 mRNA in fish fed during either the day or at night and then challenged with Aeromonas hydrophila infection. The P v-C7 cDNA of Pelteobagrus vachellii contained 2 647 bp with an open reading frame encoding a protein of 818 amino acids. Multiple sequences analysis indicated that P v-C7 included eight domains, which was similar to results for other species. Quantitative PCR analysis showed that P v-C7 was mainly expressed in the liver, spleen, intestine and head kidney tissues of healthy P. vachellii. Quantitative PCR analysis showed that C7 mRNA transcript in the liver, spleen and head kidney also increased significantly when the fish were fed at nighttime(20:00). In addition, the expression of Pv-C7 mRNA significantly increased with A. hydrophila challenge in the liver(48–96 h), spleen and head kidney(12–96 h) tissues of P. vachellii. Pv-C7 mRNA expression of the fish fed at nighttime showed significant higher than that in the fish fed at day time at 12–48 h in head kidney and 12–24 h in spleen. This study indicates that altering the feeding time from daytime to nighttime could increase P v-C7 mRNA expression, and feeding time may af fect the immune response involving C7.
文摘由于传统淡水鱼池塘养殖存在废物过量堆积、水体污染严重等问题,以及中国对水产品需求的增加,工厂化循环水养殖、集装箱、圈养模式等高质量、高产量、集约化的新型淡水鱼养殖模式逐渐得到应用。针对新型淡水鱼养殖模式存在投饲劳动强度大、自动化程度低等问题,设计了一款气送式自动投饲系统,实现了定向、定时和定量投饲功能。设计了特定的四通装置和三通装置以保证饲料的定向输送;基于计算流体力学和离散单元法(Computational fluid dynamics-Discrete element method,CFD-DEM)耦合技术,初步确定了满足投饲要求的投饲速度并由此确定了风机型号;开发了以Arduino Mega 2560单片机为核心处理器的投饲控制系统,通过时钟模块实时获取当前时间信息,通过称量传感器实时获取料仓内物料质量信息,通过蓝牙传输预计投饲区域、投饲时间和投饲质量,从而实现定向定时定量投饲;最后试制样机并进行了性能试验,两种工况下投饲的实际投饲距离与仿真结果误差分别为5.74%和9.54%,定向、定时和定量投饲可以准确实现,控制系统响应时间小于1 s,定量投饲最大误差为5.37%。研究结果表明,自动投饲系统结构可靠、控制系统精度较高,满足自动投饲要求。
