Epidemiological and clinical investigations into big liver and spleen disease of broiler breeder hens     

SK CRERAR  GM CROSS 《Australian veterinary journal》1994,71(12):410-413

SUMMARY The epidemiological and clinical features of big liver and spleen disease (BLS) in flocks on two broiler breeder farms were investigated by serology and gross pathology. The most common necropsy findings on farm 1 were splenomegaly and hepatomegaly, with kidney enlargement in some birds. In one flock (farm 1), a decline in egg production began at 40 weeks of age and lasted for 9 weeks. Seroconversion to BLS antigen was first detected at 45 weeks (3.1% of birds) and increased to 72% at 50 weeks, which coincided with clinical recovery in the flock. Antigen was detected before antibody at 44 weeks and persisted at low incidence (<15%). Farm egg production statistics and serology indicated that the disease affected all flocks on the farm. In three of eight flocks, seroconversion was detected in birds before peak production. The birds in the remaining sheds did not seroconvert or become sick until after peak production. On the second farm, sampling began within a flock already experiencing BLS. Clinical signs and pathology were similar to those seen in flocks on farm 1. However, the lesions that were seen in the pancreas in 15% of birds have not been reported previously. BLS antibody was detected in 78%, and circulating antigen in 14%, of sick birds.  相似文献   

Viking magnetic properties investigation: preliminary results     

Hargraves RB  Collinson DW  Spitzer CR 《Science (New York, N.Y.)》1976,194(4260):84-86

Three permanent magnet arrays are aboard the Viking lander. By sol 35, one array, fixed on a photometric reference test chart on top of the lander, has clearly attracted magnetic particles from airborne dust; two other magnet arrays, one strong and one weak, incorporated in the backhoe of the surface sampler, have both extracted considerable magnetic mineral from the surface as a result of nine insertions associated with sample acquisition. The loose martian surface material around the landing site is judged to contain 3 to 7 percent highly magnetic mineral which, pending spectrophotometric study, is thought to be mainly magnetite.  相似文献   

Signalling Events and Associated Pathways Related to the Mammalian Sperm Capacitation          下载免费PDF全文

DK Gangwar  SK Atreja 《Reproduction in domestic animals》2015,50(5):705-711

Capacitation is a biological phenomenon occurring prior to fertilization and is a multiple event process. Many physiological and biochemical changes takes place during the process; these changes are related to lipid composition of membrane, intracellular modulation of ion concentration, protein phosphorylation, sperm movement and membrane permeability. These events occur when the sperm is exposed to the new environment of ion concentration in the female reproductive tract. Ions such as bicarbonate and calcium facilitate capacitation by activating adenylyl cyclase, thus initiating protein kinase A (PKA) signalling cascade. Extracellular‐regulated kinase pathway is activated by ligand binding to the membrane receptors and intracellular activation by reactive oxygen species (ROS). Activation of these pathways leads to the phosphorylation of different proteins, which is associated with events such as capacitation, hyperactivation and acrosome reaction that are essential for successful fertilization. Extensive studies were carried out on protein phosphorylation in relation to capacitation, but its role still remains ambiguous.  相似文献   

Early Cleavage of Handmade Cloned Buffalo (Bubalus bubalis) Embryos is an Indicator of Their Developmental Competence and Quality          下载免费PDF全文

S Kaith  M Saini  AK Raja  AA Sahare  B Jyotsana  P Madheshiya  P Palta  MS Chauhan  RS Manik  SK Singla 《Reproduction in domestic animals》2015,50(2):214-220

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不同来源大豆品种籽粒品质的比较研究     

刘奇  谢甫绨  谢志涛 《大豆科学》2007,26(2):154-157

以辽宁20年代、辽宁当代以及与辽宁近纬度的美国俄亥俄州当代育成的亚有限结荚习性大豆品种各4个为试材,研究了不同来源大豆品种籽粒品质的差异,以及不同磷酸二铵施肥水平对大豆籽粒品质的影响.结果表明:就试验采用的品种而言,俄亥俄州立大学更注重籽粒脂肪含量的改良,而且遗传获得较大,而辽宁省育成的新品种其脂肪含量也比老品种稍高一些,蛋白质含量则有所下降.就品种来说,老品种Mukden的品质最好,蛋脂总含量高达64.7%,辽宁新品种中辽豆12号最好,俄亥俄新品种中OhioFG1最好.蛋白质含量以Mukden含量最高,达44.85%,脂肪含量以Darby含量最高,为21.39%.与不施肥相比,150 kg/hm2、300 kg/hm2磷酸二铵施肥处理会使各品种的蛋白质含量得到提高,脂肪含量有所降低,从不同来源品种组平均值来看,施用磷酸二铵300 kg/hm2的处理,大豆籽粒的蛋白质含量高于150 kg/hm2处理,脂肪含量则与之相反.  相似文献   

Phosphorus uptake and use efficiency in different varieties of bread wheat (Triticum Aestivum L)     

HS Gill  Anoop Singh  SK Sethi  RK Behl 《Archives of Agronomy and Soil Science》2013,59(6):563-572

Thirty spring wheat varieties were evaluated and classified into eight different groups on the basis of their grain yield performance and phosphorus (P) uptake using Metroglyph analysis. Significant variability was observed for grain and biomass yield, plant height, P content in grain and straw, total P uptake and phosphorus harvest index and P use efficiency traits. Varieties WH 711 and PBW 343 exhibited high grain yield as well as high P uptake (HGY-HP). WH 283 and UP 2425 with high index score of 19 and 16 respectively, constituted the high grain yield-medium P uptake (HGYMP) group. Both these varieties, though had similar grain yield of 5348 kg/ha, but WH 283 (12.64 kg/ha) utilized much lower P as compared to UP 2425 (16.94 kg/ha). Moreover, WH 283 (81.64) also showed higher values for phosphorus harvest index (PHI) than UP 2425 (67.88%). P uptake of WH 283 was comparable with that of Raj 3765 (10.78 kg/ha) and grouped into high grain yield and low P uptake (HGY-LP) group. The grain yield performance of these two varieties with a relatively low P uptake is reflected in their high index score for P use efficiency thus, earmarking them for low P regimes. Variety HW 2006, despite low grain yields of 4665 kg/ha had high index score of 16 due to its higher value for Phosphorus Biological (PBER) and Economic Yield (PEER) Efficiency Ratio as it has effected least (7.18 kg/ha) P mobilization. In addition high P translocation in the grain was also observed for this variety. Inter-mating of genotypes like HW 2006, UP 2338 and HW 2016 with those belonging to HGY-HP (PBW 343 and WH 711) and HGY-LP (Raj 3765 and WH 283) would be an ideal strategy to develop the cultivars for efficient phosphorus use.  相似文献   

中国辽宁省与美国近纬度地区新育成大豆品种的株型与产量的比较研究     

王海英  张惠君  刘闯  谢甫绨 《大豆科学》2005,24(4):286-290

试验采用中国辽宁省与美国地理纬度相近、结荚习性相同的中国和美国大豆品种各4个,在相同种植条件下对株型性状进行了比较研究,探讨了大豆高产的株型特征.结果表明:美国大豆品种的节间较短、株高较矮,分枝数较多.美国大豆品种的叶片性状比较好,下部叶片为卵圆形,由下向上叶片逐节变长,中上部叶片较细小.美国大豆品种的荚数显著多于中国大豆品种,而百粒重却显著低于中国品种.在荚粒分布上,美国品种植株上层荚粒所占比例较小,下层荚粒所占比例较大,在同等种植条件下,美国大豆品种的产量显著高于中国品种.  相似文献   

不同来源亚有限型大豆品种适应性的比较研究     

张惠君  王海英  刘闯  谢甫绨 《大豆科学》2007,26(3):332-337

采用地理纬度相似地区选育的、具有代表性的中、美大豆品种,在不同种植密度,施肥水平和种植地区条件下对大豆品种的适应性进行了比较研究.结果表明：在不同种植密度条件下美国俄亥俄州立大学选育的品种综合表现较好,都有较高的产量表现,对种植密度有较好的适应性;而辽宁省选育的品种大多产量较低,受种植密度影响较大,种植密度适应性较差.在磷酸二铵做种肥的条件下,美国俄亥俄州立大学选育的品种表现较好,对肥料的利用率较高;辽宁省选育的品种中,辽豆12号对施肥的反应较好,其它品种相对产量较低,肥力适应范围狭窄.美国俄亥俄州立大学选育的品种在不同地区种植平均产量均显著高于辽宁省选育的品种,两国品种对地区的适应性表现趋势一致,都是鞍山＞沈阳＞大连.  相似文献   

Buffalo (Bubalus bubalis) Embryonic Stem Cell‐Like Cells and Preimplantation Embryos Exhibit Comparable Expression of Pluripotency‐Related Antigens     

T Anand  D Kumar  MK Singh  RA Shah  MS Chauhan  RS Manik  SK Singla  P Palta 《Reproduction in domestic animals》2011,46(1):50-58

In this study, inner cell mass (ICM) cells were isolated from in vitro produced buffalo blastocysts and were cultured on mitomycin‐C treated buffalo foetal fibroblast feeder layer for producing embryonic stem (ES) cells. Among different sources (hatched vs expanded blastocysts) or methods (enzymatic vs mechanical), mechanical isolation of ICM from hatched blastocysts resulted in the highest primary colony formation rate and the maximum passage number up to which ES cells survived. Putative ES cells expressed alkaline phosphatase and exhibited a normal karyotype up to passage 7. Putative ES cells and embryos at 2‐ to 4‐cell, 8‐ to 16‐cell, morula and blastocyst stages strongly expressed stage‐specific embryonic antigen (SSEA)‐4 but lacked expressions of SSEA‐1 and SSEA‐3. Putative ES cells also expressed tumour rejection antigen (TRA)‐1‐60, TRA‐1‐81 and Oct4. Whereas in all early embryonic stages, TRA‐1‐60 was observed only in the periplasmic space, and TRA‐1‐81 expression was observed as small spots at a few places inside the embryos, both these markers were expressed by ICM. Oct4 expression, which was observed at all the embryonic stages and also in the trophectoderm, was the strongest in the ICM. Buffalo putative ES cells possess a unique pluripotency‐related surface antigen phenotype, which resembles that of the ICM.  相似文献   

Lystrosaurus zone (triassic) fauna from antarctica     

Kitching JW  Collinson JW  Elliot DH  Colbert EH 《Science (New York, N.Y.)》1972,175(4021):524-527

Tetrapod skeletons recently found in the Fremouw Formation in the Shackleton Glacier area, Transantarctic Mountains, include several forms that closely compare to South African species. Faunal similarities that confirm a close connection between Antarctica and Africa during the Triassic Period lend further support to the concept of Gondwanaland and continental drift.  相似文献