Effects of a Progesterone‐Based Oestrous Synchronization Protocol in 51‐ to 57‐Day Postpartum High‐Producing Dairy Cows     

I Garcia‐Ispierto  F Lpez‐Gatius  G Bech‐Sbat  JL Yniz  E Angulo  C Maris  S Floc&#x;h  A Martino 《Reproduction in domestic animals》2010,45(5):e168-e173

The aim of this study was to investigate the effect of applying a progesterone‐based oestrous synchronization protocol at 51–57 days postpartum in high‐producing dairy cows. The data analysed were derived from 1345 lactating cows. Cows between 51 and 57 days postpartum were assigned to the groups: control, PRID (receiving a progesterone‐releasing intravaginal device for 9 days, and prostaglandin F_2α 24 h before PRID removal) or GnRH–PRID (the same as the PRID group plus GnRH at PRID insertion). Oestrus was detected by using pedometers and confirmed by examination of the genital tract at AI. Oestrous and conception rates before days 71–77 postpartum, pregnancy loss in early pregnant cows or the cumulative conception rate registered on day 120 postpartum were considered as the dependent variables in four consecutive logistic regression analyses. Based on the odds ratios, the oestrous rate increased by a factor of 1.73 in cows showing oestrus before treatment for each unit increase in the number of previous oestruses; decreased by a factor of 0.44 in the control group with respect to the treatment groups; and by a factor of 0.61 in cows without luteal structures at treatment with respect to cows with corpora lutea. The conception rates of cows inseminated before days 71–77 postpartum remained similar across the groups, whereas the likelihood of pregnancy loss for cows becoming pregnant during this period was 0.11 times lower in the PRID group than in the control. Based on the odds ratio, the likelihood of a higher cumulative conception rate on day 120 postpartum: increased in cows showing oestrus before treatment by a factor of 1.41 for each unit increase in the number of previous oestruses, was reduced 0.56‐fold in control cows compared with treated cows, and was also reduced by a factor of 0.98 for each kilogram of milk production increase recorded at treatment. In conclusion, although oestrous synchronization programmes performed in this study did not improve fertility, cows treated with progesterone could be inseminated earlier than untreated cows, such that the treatments increased the cumulative pregnancy rates determined on day 120 postpartum. In addition, fewer pregnancy losses were observed in early pregnant cows in the PRID group than the GnRH–PRID group.  相似文献   

Systemic Immunosuppression by Methylprednisolone and Pregnancy Rates in Goats Undergoing the Transfer of Cloned Embryos     

C Feltrin  CA Cooper  N Mohamad‐Fauzi  VHV Rodrigues  LH Aguiar  S Gaudencio‐Neto  LT Martins  CEM Calderón  AS Morais  IS Carneiro  TM Almeida  ING Silva  JL Rodrigues  EA Maga  JD Murray  AB Libório  LR Bertolini  M Bertolini 《Reproduction in domestic animals》2014,49(4):648-656

The presence of the zona pellucida has been perceived as a requirement for the oviductal transfer of cloned embryos at early stages of development while protecting the embryo from an immune system response. We hypothesized that steroid hormone therapy could reduce a potential cellular immune response after the transfer of zona‐free cloned embryos into the oviduct of recipient female goats. In Experiment 1, seven does were used to study the systemic immunosuppressant effect of the methylprednisolone administration (for 3 days) on blood cell counts. Whole blood was collected prior to treatment with methyprednisolone and then on Days 1, 2, 3, 4, 7, 14, 21 and 28 after the first dose of methylprednisolone for the analysis of haematological parameters. Methylprednisolone treatment significantly reduced circulating white blood cells and neutrophils in comparison with pre‐treatment levels, demonstrating a systemic immunosuppressant effect. In Experiment 2, a group of 58 does were used as recipient females to study the effect of administration of methylprednisolone for 3 days on the establishment of pregnancies after the transfer of zona‐free cloned embryos into the oviducts. No effects on pregnancy rates on Day 30 were observed regarding the distinct treatment groups (control vs. methylprednisolone), the source of oocytes (in vivo‐ vs in vitro‐matured) or the presence or absence of the zona pellucida in embryos. In summary, methylprednisolone was effective at inducing a systemic immunosuppressed state in goats, but the treatment prior to embryo transfer did not affect pregnancy rates. Moreover, pregnancy rates were similar between zona‐free and zona‐intact goat cloned embryos.  相似文献   

Yield of synthetic backcross-derived lines in rainfed environments of Australia   总被引：3，自引：1，他引：3  

Francis C. Ogbonnaya  Gouyou Ye  Richard Trethowan  Fernanda Dreccer  Douglas Lush  John Shepperd  Maarten van Ginkel 《Euphytica》2007,157(3):321-336

Wheat is one of the major food crops in the world. It is Australia’s largest crop and most important agricultural commodity. In Australia the crop is grown under rainfed conditions with inherently important regional environmental differences; wheat growing areas are characterized by winter dominant rainfall in southern and western Australia and summer rainfall in northern Australia. Maximizing yield potential across these diverse regions is dependent upon managing, either genetically or agronomically, those factors in the environment that limit yield. The potential of synthetic backcross lines (SBLs) to increase yield in the diverse agroecological zones of Australia was investigated. Significant yield advantages were found for many of the SBLs across diverse environments. Depending on the environment, the yield of the SBLs ranged from 8% to 30% higher than the best local check in Australia. Apart from adaptation to semiarid water stressed conditions, some SBLs were also found to be significantly higher yielding under more optimal (irrigated) conditions. The four testing environments were classified into two groups, with the northern and southern environments being in separate groups. An elite group of SBLs was identified that exhibited broad adaptation across all diverse Australian environments included in this study. Other SBLs showed specific adaptation to either northern or southern Australia. This study showed that SBLs are likely to provide breeders with the opportunity to significantly improve wheat yield beyond what was previously possible in a number of diverse production environments.  相似文献   

Care and Handling of Australian Native Animals: Emergency Care and Captive Management     

HELEN GEORGE  BRIAN G RICH  JL CHURCHILL  RC CHURCHILL 《Australian veterinary journal》1994,71(2):60-60

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A comparison of the reduction in immunoglobulin (IgG) concentration of frozen equine plasma treated by three thawing techniques     

JL O'RIELLY 《Australian veterinary journal》1993,70(12):442-444

SUMMARY: The IgG concentration of plasma from 13 mares was measured by radial immunodiffusion when fresh and after storage at -4°C and thawing by 3 methods. There was no significant (P > 0.05) reduction in the IgG concentration when plasma was thawed over 6 hours at 22°C (1352.9 ± 101.6 mg/dL) (mean ± SEM) compared with the fresh sample (1369.5 ± 88.1 mg/dL). In contrast, there was a significant (P < 0.05) reduction in the IgG concentration of plasma that was rapidly thawed at 57°C over 50 minutes (1142.9 ±66.2 mg/dL), or placed in a microwave oven for 20 to 25 minutes (1093.4 ± 74.4 mg/dL). When plasma is administered to hypo-gammaglobulinaemic newborn foals, a larger volume is required when thawing is rapid than when thawing is slow or when fresh plasma is administered.  相似文献   

Serological evidence of Neospora caninum in alpacas from eastern Australia          下载免费PDF全文

JS King  JL Vaughan  PA Windsor 《Australian veterinary journal》2015,93(7):259-261

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魔芋飞粉生物碱的抑菌活性及抑菌机理研究     

周琦  张宝善  韦露莎 《西北农林科技大学学报(自然科学版)》2019,47(3):121-128

【目的】探究魔芋飞粉生物碱(Alkaloid from konjac powder,AKP)的抑菌作用及其对大肠杆菌和金黄色葡萄球菌的抑菌机理,为新型天然抑菌剂和防腐剂的开发提供理论依据。【方法】采用液体倍比稀释法,确定AKP对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌、鼠伤寒沙门氏菌4株供试菌的最小抑菌质量浓度(Minimum inhibitoryconcentration,MIC),并采用牛津杯法测定AKP对上述4株供试菌的抑菌圈大小;通过测定在AKP作用下,大肠杆菌和金黄色葡萄球菌的生长曲线、菌体培养液电导率及观察细胞膜完整性、细胞形态等,对AKP的抑菌作用及其机理进行分析。【结果】AKP对4株供试菌均有明显的抑制作用,对金黄色葡萄球菌的抑菌作用最强(MIC为10mg/mL),大肠杆菌次之(MIC为20mg/mL)。AKP对供试菌的抑菌圈直径依次为金黄色葡萄球菌大肠杆菌枯草芽孢杆菌鼠伤寒沙门氏菌。菌体生长曲线显示,AKP对大肠杆菌和金黄色葡萄球菌的生长有明显的抑制效果。AKP作用后,大肠杆菌和金黄色葡萄球菌细胞膜受损,存活率显著降低,菌体培养液电导率显著上升。电镜观察发现,AKP使菌体细胞膜出现破损,部分菌体出现空腔。【结论】AKP具有抑菌作用,其可能通过破坏细菌细胞膜结构而导致内容物外泄,进而影响细胞的生长代谢或造成细胞死亡,从而抑制其生长。  相似文献   

Abrupt climate events 500,000 to 340,000 years ago: evidence from subpolar north atlantic sediments     

DW Oppo  JF McManus  JL Cullen 《Science (New York, N.Y.)》1998,279(5355):1335-1338

Subpolar North Atlantic proxy records document millennial-scale climate variations 500,000 to 340,000 years ago. The cycles have an approximately constant pacing that is similar to that documented for the last glacial cycle. These findings suggest that such climate variations are inherent to the late Pleistocene, regardless of glacial state. Sea surface temperature during the warm peak of Marine Isotope Stage 11 (MIS 11) varied by 0.5 degrees to 1 degrees C, less than the 4 degrees to 4.5 degrees C estimated during times of ice growth and the 3 degrees C estimated for glacial maxima. Coherent deep ocean circulation changes were associated with glacial oscillations in sea surface temperature.  相似文献   

Magnetic Field and Plasma Observations at Mars: Initial Results of the Mars Global Surveyor Mission   总被引：2，自引：0，他引：2  

MH Acu?a  JEP Connerney  P Wasilewski  RP Lin  KA Anderson  CW Carlson  J McFadden  DW Curtis  D Mitchell  H Reme  C Mazelle  JA Sauvaud  C d'Uston  A Cros  JL Medale  SJ Bauer  P Cloutier  M Mayhew  D Winterhalter  NF Ness 《Science (New York, N.Y.)》1998,279(5357):1676-1680

The magnetometer and electron reflectometer investigation (MAG/ER) on the Mars Global Surveyor spacecraft has obtained magnetic field and plasma observations throughout the near-Mars environment, from beyond the influence of Mars to just above the surface (at an altitude of approximately 100 kilometers). The solar wind interaction with Mars is in many ways similar to that at Venus and at an active comet, that is, primarily an ionospheric-atmospheric interaction. No significant planetary magnetic field of global scale has been detected to date (<2 x 10(21) Gauss-cubic centimeter), but here the discovery of multiple magnetic anomalies of small spatial scale in the crust of Mars is reported.  相似文献   

The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor   总被引：1，自引：0，他引：1  

GM Keating  SW Bougher  RW Zurek  RH Tolson  GJ Cancro  SN Noll  JS Parker  TJ Schellenberg  RW Shane  BL Wilkerson  JR Murphy  JL Hollingsworth  RM Haberle  M Joshi  JC Pearl  BJ Conrath  MD Smith  RT Clancy  RC Blanchard  RG Wilmoth  DF Rault  TZ Martin  DT Lyons  PB Esposito  MD Johnston  al et 《Science (New York, N.Y.)》1998,279(5357):1672-1676

The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere.  相似文献