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1.
Hu Sheep is a local sheep breed in the plain of Taihu,China.Due to the natural conditions in Taihu and human domestication,Hu Sheep is gradually featured with high adaptability,fast growth rate,early maturity and high productivity,which make them to be a unique and rare breed of sheep.In the present study,an experiment was conducted by means of instantaneous scan sampling,focal animal sampling and all-occurrence sampling to learn about Hu Sheep's behavior and activity pattern under certain feeding management and ecological condition.The result showed that the activity time budgets for several behaviors were different between rams and ewes,with respect to feeding (rams 30.60% vs.ewes 33.23%),ruminating (33.43% vs.35.30%);sleeping (19.92% vs.13.69%),standing (4.13% vs.5.26%),moving (8.10% vs.7.46%),and other behaviors (3.86% vs.5.06%).A circadian activity rhythm was shown in some behaviors;e.g.,total feeding time was greater in the daytime than at night,whereas resting time showed the opposite tendency.Moving mostly occurred in the daytime,and ruminating mainly occurred at night.Additionally,feeding activity occurred 32.22 times per day in rams and 31.73 times per day in ewes,whereas ruminating activity after feeding occurred 19.83 times per day in rams and 24.34 times per day in ewes.For each food bolus,the average ruminating time was 51.22 s in rams and 49.52 s in ewes,with 68.22 bouts of rumination per day in rams and 57.35 bouts of rumination in ewes.By conducting the experiment,we studied and grasped the local Hu Sheep's main behavior and regularity which are of great significance on improving the feeding management and reducing diseases.  相似文献   

2.
By using data collected during a continuous circumnavigation of the Southern Hemisphere, we observed clear patterns in the population-genetic structure of Prochlorococcus, the most abundant photosynthetic organism on Earth, between and within the three Southern Subtropical Gyres. The same mechanisms that were previously invoked to account for the vertical distribution of ecotypes at local scales accounted for the global (horizontal) patterns we observed. Basin-scale and seasonal variations in the structure and strength of vertical stratification provide a basis for understanding large-scale horizontal distribution in genetic and physiological traits of Prochlorococcus, and perhaps of marine microbial communities in general.  相似文献   

3.
对西方(ApismeliferaL.)采用1和2日龄工蜂幼虫产浆的王台接受率和不同时间取浆浆量进行研究,结果显示:(1)2日龄工蜂幼虫的王台接受率(80.67%)极显著高于1日龄(49.33%)(P<0.01);(2)1和2日龄幼虫产浆的台平均产浆量最高峰分别在各自移虫后第84h和第72h,浆量较高时段分别在移虫后第78—90h和第68—78h.2个日龄幼虫产浆最高浆量之间及浆量较高时段的浆量均无显著差异,但采用2日龄幼虫产浆的比1日龄幼虫的提前12h达到台平均产浆量高峰和浆量较高时段.(3)采用2日龄幼虫产浆其总产浆量可比采用1日龄的增加56%.通过试验认为,西方蜜蜂产浆采用2日龄幼虫,并在移虫后第66—78h内取浆最适  相似文献   

4.
颗粒细胞是卵巢卵泡重要的结构组分,其形态、功能伴随原始卵泡的生长启动、增殖、分化、闭锁、排卵 以及黄体形成等生理过程发生各种变化。颗粒细胞是研究细胞增殖、分化和细胞相互作用、信号转导通路的理想细 胞模型。利用注射器吸取有腔卵泡卵泡液,成功分离培养了猪有腔卵泡的颗粒细胞,并进行了FSHR 免疫荧光检测 以及原代猪卵巢颗粒细胞生长活力检测,结果表明院该细胞对FSHR 的免疫荧光呈阳性。流式细胞仪检测发现该细 胞的细胞周期为24 h,但在培养4 d时细胞的活力最强。该研究结果为进一步研究母猪卵巢卵泡功能奠定了基础。  相似文献   

5.
提取牛粪堆肥中的溶解性有机物(dissolved organic matter,DOM),并将DOM转移至含有铜绿微囊藻Microcystis aeruginosa FACHB905细胞的培养液中,DOM含量以溶解性有机碳(DOC)质量浓度进行衡量,分别控制培养液中DOC的终质量浓度为0、15、30、60、90、120 mg/L(分别记为CK、T1、T2、T3、T4、T5)。通过测定藻细胞密度、色素含量和藻毒素含量,研究DOM对铜绿微囊藻生理生化及产毒特性的影响。结果表明:1)M.aeruginosa FACHB905受DOM影响,在处理后第2天,各DOM处理的细胞密度与CK相比均有所增加,T4处理的细胞密度(5.97×106个/m L)最大,比CK增加了21.67%,处理后第4天,T1、T2、T3处理均能够促进细胞生长,T2处理的细胞密度(9.23×10~6个/m L)最大,比CK增加了15.27%,而T4、T5处理抑制细胞生长,处理后第6天,仅T1及T2处理能够促进细胞生长,T1处理的细胞密度(13.34×10~6个/m L)最大,比CK增加了10.35%,而T3、T4、T5处理抑制细胞生长;2)堆肥来源DOM能够抑制藻毒素的合成,单位细胞藻毒素Microcystin–LR含量在处理后第2天T5处理的最低,比CK下降了53.13%,而Dha7–Microcystin–LR含量在处理后第4天T5处理的最低,与CK比较下降了78.51%;3)各DOM处理对单位细胞内Chl–a和Carotenoid的合成没明显影响。  相似文献   

6.
对福建省顺昌县农户进行随机调查,并用宏观数据进行检验,将林业劳动分为林业生产性劳动、林业服务性劳动和林业加工性劳动。根据调查样本,核算木质林产品生产性劳动报酬约53元/工日,非木质林产品生产性劳动报酬约80元/工日,林业服务性劳动报酬约106元/工日,林业加工性劳动报酬约40元/工日。指出了林业劳动报酬产生差异的主要原因是由劳动供求情况及农户所拥有的生产要素所决定的。  相似文献   

7.
Prochlorococcus is the numerically dominant phytoplankter in the oligotrophic oceans, accounting for up to half of the photosynthetic biomass and production in some regions. Here, we describe how the abundance of six known ecotypes, which have small subunit ribosomal RNA sequences that differ by less than 3%, changed along local and basin-wide environmental gradients in the Atlantic Ocean. Temperature was significantly correlated with shifts in ecotype abundance, and laboratory experiments confirmed different temperature optima and tolerance ranges for cultured strains. Light, nutrients, and competitor abundances also appeared to play a role in shaping different distributions.  相似文献   

8.
Zhang S  Bryant DA 《Science (New York, N.Y.)》2011,334(6062):1551-1553
It is generally accepted that cyanobacteria have an incomplete tricarboxylic acid (TCA) cycle because they lack 2-oxoglutarate dehydrogenase and thus cannot convert 2-oxoglutarate to succinyl-coenzyme A (CoA). Genes encoding a novel 2-oxoglutarate decarboxylase and succinic semialdehyde dehydrogenase were identified in the cyanobacterium Synechococcus sp. PCC 7002. Together, these two enzymes convert 2-oxoglutarate to succinate and thus functionally replace 2-oxoglutarate dehydrogenase and succinyl-CoA synthetase. These genes are present in all cyanobacterial genomes except those of Prochlorococcus and marine Synechococcus species. Closely related genes occur in the genomes of some methanogens and other anaerobic bacteria, which are also thought to have incomplete TCA cycles.  相似文献   

9.
对国槐Sophora japonica槐角种胚细胞悬浮培养的动力学进行研究,在优化细胞接种量的基础上,分析测定培养周期内不同培养阶段的槐角细胞生长和培养基中碳源、氮源、磷源的消耗,以及细胞的鲜质量、干质量和黄酮产量的变化,从而了解细胞生长、营养消耗与次生代谢产物积累的基本规律,为建立结构化动力学模型奠定基础。结果表明:①初始接种量为40.000 gL-1时,最利于细胞的培养;②细胞的培养周期约为27 d,经过27 d的培养,生物量和黄酮的产量达到最高,分别为9.733 gL-1和53.566 mgL-1,对细胞比生长速率和黄酮比合成速率进行分析,得出黄酮的积累和细胞的生长为部分生长偶联型,在6~12 d呈负相关,12~33 d呈正相关;③基质中的碳源、氮源、磷源都是在0~6 d被迅速消耗,到12 d时消耗量达到总量的80.00%以上。在氮源的吸收上,铵态氮(NH4+)先于硝态氮(NO3-)的吸收。碳源、氮源、磷源的消耗与细胞生长和产物的积累密切相关。图10参25  相似文献   

10.
哺乳仔猪生后7d龄出现觅食行为,仔猪生后3~5d龄有饮水表现。57.4%的仔猪吃奶或拱奶后马上吃料。仔猪生后5~14d每昼夜睡眠时间平均为1065min(17.75h),间隔时间较短,21~2幼龄每昼夜平均睡眠时间为837min(13.95h).哺乳仔猪生后5~10d龄每昼夜平均吃奶次数达30.7次,平均间隔时间为49.1min。到14d龄,吃奶次数明显减少,持续时间也缩短,而间隔时间延长到67.6min。从第21d龄到断奶(第35d龄)吃奶(或拱奶)次数一般都在35次左右,间隔和持续时间无明显规律。  相似文献   

11.
农业固碳研究多针对农田土壤固碳,且农业固碳受气候、生物、土壤等因素影响较大,环境因子不可控,导致农业固碳效率低。目前,农业固碳鲜少针对设施农业固碳,而随着现代设施农业发展规模日益增大、环境调控设施设备趋于自动化智能化,资源利用效率、单位面积土壤产出率及生产效率都大大提高,设施农业打破了时间和空间的界限,在一定程度上提高了作物产量及其固碳效益。为此,通过分析设施农业发展现状,结合农业固碳研究的现状及存在问题,在设施农业发展的基础上分析了设施农业在固碳方面具有生产周期长、环境因子可控、半封闭式生产及可利用资源广且资源效率利用率高的优势,并探讨了设施农业固碳研究的重要性,结合环境发展需求及碳贸易,提出了发展设施农业固碳思路和前景。  相似文献   

12.
Prochlorococcus ecotypes are a useful system for exploring the origin and function of diversity among closely related microbes. The genetic variability between phenotypically distinct strains that differ by less that 1% in 16S ribosomal RNA sequences occurs mostly in genomic islands. Island genes appear to have been acquired in part by phage-mediated lateral gene transfer, and some are differentially expressed under light and nutrient stress. Furthermore, genome fragments directly recovered from ocean ecosystems indicate that these islands are variable among cooccurring Prochlorococcus cells. Genomic islands in this free-living photoautotroph share features with pathogenicity islands of parasitic bacteria, suggesting a general mechanism for niche differentiation in microbial species.  相似文献   

13.
河南省扶沟县农牧业全面发展的调查分析   总被引:1,自引:0,他引:1  
 扶沟县养牛业发展很快,每5.6亩地一头牛,人均牛肉占有量比全国高1倍。由于牛种改良慢,出栏率还低,每头存栏牛产肉量仅为先进国家的40%,故潜力极大。猪、牛头数比为0.55∶1,猪、牛产肉比为2∶1,猪的饲料转化率较高,有必要提高牲猪出栏比例。扶沟县粮、棉人均占有量分别达470.3和71.1公斤,在全国也是先进的。但总肉品生产量过低。目前,扶沟县已形成了粮、棉、畜三元结构雏形。在粮草兼作,粮肉生产关系和畜牧业内部结构上还有待进一步合理化;农牧营养物质相互转化都在30%上下,宜进一步强化。  相似文献   

14.
【目的】了解硫酸头孢喹肟乳房注入剂(干乳期)对健康奶牛的正常体温、日产奶量、奶中体细胞数和乳房内菌群的影响。【方法】选用初产和经产健康泌乳期奶牛各6头,所选奶牛在试验前30日内未全身性或乳房内给予任何抗生素,奶牛正常饲养管理,日粮和饮水中不含有任何抗菌药物。给药前1和0日统计记录各试验奶牛的直肠温度、日产奶量(早、中、晚3次产奶量的加和)、检测每个乳区采集奶样的体细胞数,并对给药前0日的奶样进行病原菌分离鉴定。4个乳区分别单次给予硫酸头孢喹肟乳房注入剂(干乳期)。给药后的第1、3、5、7、10天分别统计记录每头奶牛的日产奶量,给药后的第12 h、3、5、7、10天分别采集奶样进行体细胞检测,同时检查直肠温度;给药后的第10天,采集奶样进行病原菌分离鉴定。比较奶牛用药前后直肠温度、日产奶量、牛奶体细胞数和奶中病原菌的变化。整个试验期间连续观察给药奶牛是否出现红、肿、热、痛等临床症状。【结果】给药前1天、0天和最后一次给药后的第1、3、5、7、10天,试验奶牛的日产奶量平均值分别为28.8、27.7、28.1、28.7、28.8、29.2和29.6 kg,卡方检验显示无显著性差异(P0.05);各时间点采集的奶中体细胞数大都维持在30—50万个/m L之间;各时间点测得的奶牛直肠温度平均值分别为38.3、38.4、38.3、38.3、38.3、38.2和38.3℃,无显著性差异(P0.05);病原菌检测结果显示,在给药前0日采集的奶样中,分离到大肠杆菌8株、链球菌5株和葡萄球菌7株,给药后第10天采集的奶样中大肠杆菌、链球菌和葡萄球菌各分离到1株,明显减少,且没有增加新的病原菌。【结论】硫酸头孢喹肟乳房注入剂(干乳期)对奶牛正常体温、产奶量和奶中体细胞数等没有不良影响,该制剂用于奶牛是安全的。  相似文献   

15.
Pinealectomized Syrian hamsters were injected thrice daily with 25 micrograms of melatonin per injection. The injections were administered at 3-hour intervals either during the day or during the night of a photoperiodic cycle of 14 hours of light and 10 hours of darkness. After 6 weeks of treatment with melatonin during the night, both pinealectomized and intact hamsters had reduced testis weight, and pinealectomized hamsters showed decreased levels of serum gonadotropins. Injection of melatonin during the day for 7 weeks either once (75 micrograms) a day or thrice (25 micrograms per injection) daily caused a reduction in testis weight in pinealectomized hamsters. Both pinealectomized and intact females injected with melatonin thrice daily during the day became anovulatory by week 7 of treatment. These results are similar to those observed when hamsters are exposed to a short photoperiod, suggesting that melatonin may be acting as a hormone in mediating the effects of photoperiod on the reproductive system of the Syrian hamster.  相似文献   

16.
研究了蜂王信息素在蜂箱内通过单独以气流方式传递(A组)、工蜂与气流两种方式传递(B组)以及蜂王、工蜂和气流3种方式共同传递(C组)时对蜂群内工蜂出勤情况以及王台形成数量的影响。结果表明,工蜂出勤情况为:C组一天的出勤总次数和各时刻出勤次数多于B组和A组,B组出勤总次数和各时刻出勤次数多于A组;王台形成数量为:A组第3 d出现自然王台,第10 d出现改造王台;B组第6 d出现自然王台,第17 d出现改造王台,比A组分别推迟了3 d和7 d;C组第10 d出现自然王台,但直至试验结束仍没有出现改造王台;A组自然王台和改造王台数量高达929只,B组634只,C组194只,这一数据表明,如果没有蜂王传递信息素,蜂群就会出现改造王台。  相似文献   

17.
岳向国  张卫  邓麦村 《安徽农业科学》2011,39(6):3223-3226,3236
[目的]研究原位吸附对葡萄悬浮培养体系生长和生产的影响。[方法]考察5种常用吸附剂对葡萄细胞生长及芪类和花色苷生产的影响。并对筛选出的HP2MGL和XAD-7的最佳添加浓度进行了研究。[结果]在添加浓度为100 g/L的XAD-7和HP2MGL的处理组中反式白藜芦醇的产量最高,在第7天达到251.4和258.8 mg/L,将白藜芦醇苷和白藜芦醇的产量换算成总芪产量(mmol/L),结果显示,添加XAD-7和HP2MGL后,在第7天芪类产量达到最大,分别为1.4和1.5 mmol/L,比对照处理的芪类产量高27%。在筛选出XAD-7和HP2MGL后,又考察了添加不同浓度XAD-7和HP2MGL对葡萄细胞生长、花青素和芪类生产的影响。结果表明最佳优化结果为添加200 g/L的HP2MGL,此时,体系中反式白藜芦醇在第7天的产量为568 mg/L。[结论]200 g/L HP2MGL大孔树脂可以显著促进葡萄悬浮培养细胞体系中反式白藜芦醇产量。  相似文献   

18.
[Objective] This study aimed to investigate the combination effects of ligustrazine and cis-dichlorodiamine platinum(DDP) on anti-proliferation, cell cycle and apoptosis of SGC-7901 cell lines in vitro. [Method] SGC-7901 cells were treated with ligustrazine and DDP alone or combined for 48 h for morphology assay.Anti-proliferative effects with the same treatment for 24, 48 and 72 h were assayed by MTT method, respectively. Cell cycle distribution and apoptosis assay of treated cells were performed in flow cytometry. Zhengjun Jin's protocol was used to assay the effect of drug combination. [Result] Ligustrazine significantly increased the proliferation inhibition rate of DDP on SGC-7901 cells in combination with DDP, comparing with the effects of ligustrazine or DDP alone, and exhibited synergistic antitumor effect. The combination drug treatment induced cell cycle arrest occurred in S and G2 phase of the cell cycle and increased the apoptosis rate significantly.[Conclusion] Our results indicate that ligustrazine, as a low-toxic and natural herbal component, can significantly increase the anti-proliferative effect and apoptosis rate of antitumor drug DDP on human gastric carcinoma SGC-7901 cells.  相似文献   

19.
为探索水平基因转移在绿球蓝细菌基因组多样性中的作用,5个高光适应性绿球蓝细菌基因组被比较.先用BLASTP两两最佳匹配搜索和基因位置保守性的方法预测直系同源基因,并进一步计算每个基因组中所有基因在其他4种绿球蓝细菌基因组中直系同源基因的数量,从而达到识别外源基因的目的;而基因组岛是指由1个或几个连续外源基因组成的区域.结果表明:在5个绿球蓝细菌基因组中共识别出了16至52个不等的基因组岛,它们中的许多基因在病毒基因组或富含病毒的环境样本中都有同源基因.以上这些结果显示,在绿球蓝细菌中,病毒可能介导了基因的水平转移,从而导致了基因组的多样性.  相似文献   

20.
以泗杂3号为试验品种,研究了施钾量对其生育特性、产量和产量构成的效应。结果表明,施用适量的钾肥对棉花早发和产量提高具有促进作用,主要表现为:①见蕾日期提前3~4 d,见花日期提前2~4 d,吐絮日期提前3~5 d;②株高适宜,株高日增量、果枝数、单株果节量适宜;③单铃重和单株成铃数显著提高,皮棉产量显著增加。对于综合生育特性、棉产量和产量构成,240 kg/hm2施钾量的促进效应最好。  相似文献   

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