Failure of an intramuscular injection of an analogue of gonadotrophin-releasing hormone 11 to 13 days after insemination to increase pregnancy rates in dairy cattle     

TF JUBB  D. ABHAYARATNE†  J. MALMOS‡  GA ANDERSON 《Australian veterinary journal》1990,67(10):359-361

At 11 to 13 d after insemination, 1028 dairy cows on 19 farms were given an intramuscular injection of 10 micrograms of the GnRH analogue buserelin. Their reproductive performance was compared to 1022 control cows receiving a placebo. The GnRH analogue-treated cows had fewer short interoestrous intervals compared to the control cows, but there were no significant differences in pregnancy rates to either the insemination preceding or following treatment, in calving to conception interval, or to percent pregnant by the end of mating. There were no differences between treatments in herds of high, average or low pregnancy rate, in 2-year-old cows or cows greater than 2-years-old and in cows calved 40 d or less, or greater than 40 d. The use of 10 micrograms of the GnRH analogue, buserelin, 11 to 13 d after insemination, cannot be recommended as a method of improving reproductive performance in dairy herds.  相似文献   

Reproductive performance of Thoroughbred mares on six commercial stud farms     

I BRÜCK  GA ANDERSON  JH HYLAND † 《Australian veterinary journal》1993,70(8):299-303

The records of 1630 mare years from 6 Thoroughbred stud farms in south eastern Australia were analysed for the years 1981 to 1986. Overall pregnancy and foaling rates were 83.9% and 69.3%, respectively. When calculated per served oestrous cycle, pregnancy and foaling rates were 54.7% and 43.1%, respectively. Pregnancy and foaling rates were higher (P < 0.001) for mares 3 to 10 years of age than for older mares. There was no difference in the pregnancy rates of maiden, barren and foaling mares. The foaling rate was significantly higher (P < 0.001) in mares that became pregnant during the first served oestrous cycle (77.8%) than in mares that needed two served oestrous cycles to become pregnant (65.4%). Of all diagnosed pregnancies, 19.5% were not completed. Pregnancy loss was lower (P < 0.05) in maiden (12.4%) than in barren (19.7%) or foaling (20.9%) mares. Twins were diagnosed in 7.8% of all pregnancies. If one conceptus was lost without external interference, 84.1% of pregnancies went to term. If one conceptus was manually crushed, 55.9% of pregnancies were maintained. If prostaglandin was used to terminate twin pregnancies, 60% of mares so treated produced foals the following year.  相似文献   

Follicle Turnover and Pregnancy Rates Following Oestrus Synchronization Protocols in Mediterranean Italian Buffaloes (Bubalus bubalis)     

GA Presicce  EM Senatore  G De Santis  A Bella 《Reproduction in domestic animals》2005,40(5):443-447

An ultrasound assessment of follicle turnover following two different protocols for synchronization of oestrus and ovulation, as well as an assessment of achieved synchronization between ovulation and AI and conception rates in nulliparous and pluriparous buffaloes were carried out during months of increasing day length. Nulliparous buffaloes (n = 30) were subjected only to Ovsynch protocol whereas pluriparous buffaloes (n = 31) were assigned to Ovsynch (n = 14) or to PRID-pregnant mare serum gonadotrophin (PMSG) (n = 17) protocol according to the presence of functional CL confirming cyclic and acyclic conditions. Ultrasound examination of ovarian follicular dynamics at critical days in the course of synchronization treatments was employed to monitor the fate of the largest available follicles at the beginning of treatments. Such available dominant follicle would persist throughout the protocol as ovulating follicle (no-follicle shift) or would regress giving way to a new follicle to become dominant and ovulate (follicle shift). Furthermore, ultrasound monitoring would determine the degree of synchronization of ovulation and final outcome represented by pregnancy rates. Pregnancy rate following Ovsynch protocol was 40% (12/30) and 42.8% (6/14) in nulliparous and pluriparous buffaloes respectively (p = 0.8575). Most ovulations were synchronized and recorded at AI and the following day in nulliparous (24/30; 80%) and pluriparous (12/14; 85.7%) buffaloes respectively (p = 1.000). A follicle shift was recorded in 14 of 30 (46.6%) and 11 of 14 (78.5%) in nulliparous and pluriparous buffaloes respectively (p = 0.0466). Among established pregnancies: eight derived from follicle shift (66.6%) and four from no-follicle shift (33.3%) in nulliparous buffaloes, p = 0.0729 whereas in pluriparous buffaloes five (83.3%) derived from follicle shift and one from no-follicle shift (16.6%), p = 0.6154. Collectively, from 18 pregnancies in nulliparous and pluriparous buffaloes following Ovsynch protocol, 13 derived from follicle shift (72.2%) and five from no-follicle shift (27.7%), p = 0.0860. Pregnancy rate in pluriparous buffaloes following PRID-PMSG protocol was 70.5% (12/17). The majority of ovulations were synchronized and recorded at first, second AI and following day (13/17; 76.4%). A follicle shift occurred in 15/17 buffaloes (88.2%) and among the 12 recorded pregnancies, 11 derived from follicle shift (91.6%), p = 0.5147. In conclusion, pregnancy rates following Ovsynch protocol were similar in nulliparous and pluriparous cyclic buffaloes. A progestagen treatment on acyclic buffaloes but still displaying some ovarian follicular dynamics, resulted in significantly higher pregnancy rate compared with Ovsynch (p = 0.0376). According to the time of scheduled AI, a high degree of synchronized ovulations were recorded following the implementation of both protocols.  相似文献   

The arctic mirage and the early north atlantic     

Sawatzky HL  Lehn WH 《Science (New York, N.Y.)》1976,192(4246):1300-1305

The arctic mirage is a phenomenon that is common in higher latitudes. It occurs under conditions of pronounced temperature inversion, which impart to the air a refractive capability that may equal or exceed the curvature of the earth. Manifestations of the arctic mirage, though largely forgotten in modern times, are described in the earliest accounts of North Atlantic discovery. This interdisciplinary investigation, combining historical induction with scientific observation and analysis, has suggested a new interpretation of historical events. We believe that information gleaned from these mirages was vital to Norse navigation and exploration in the North Atlantic. We further contend that the mirage may furnish a logical basis for the pervasive ancient and medieval concept of the flat or saucer-shaped world.  相似文献   

玉树州特色中藏药发展对策及前景分析     

李积谦  尕玛旺扎  春雨  姜春邦 《青海农林科技》2006,(4):42-44

根据玉树特殊的地理环境,气候特点,特色中藏药自然资源优势及其形态特征,提出了玉树特色中藏药发展对策。  相似文献   

Epidemiological Description of Cystic Ovarian Disease in Argentine Dairy Herds: Risk Factors and Effects on the Reproductive Performance of Lactating Cows     

L Cattaneo  ML Signorini  J Bertoli  JA Bartolomé  NC Gareis  PU Díaz  GA Bó  HH Ortega 《Reproduction in domestic animals》2014,49(6):1028-1033

To describe the epidemiology of cystic ovarian disease (COD), to find possible risk factors associated with the incidence of cysts and to analyse the impact of COD on the reproductive performance of dairy cows, databases from 22 dairy herds from the main dairy region in Argentina were retrospectively evaluated throughout a 3‐year period (2009–2011). A total of 248 COD cases over 9156 parturitions were recorded, resulting in a cumulative incidence rate of 2.7%. Cystic ovarian disease incidence density was lower during the first 100 days post‐partum (DPP) than during later stages of lactation. Seasonality had a significant influence on the disease presentation with higher incidence rates during winter and spring. Cows with a previous diagnosis of clinical mastitis showed 2.72 times more chances of developing ovarian cysts. Cystic cows had longer calving to first service and calving to conception intervals and lower conception rate than controls.  相似文献   

平菇津平90特性及栽培技术   总被引：1，自引：1，他引：1  

班立桐  谷荣祥  高燕  王文治 《天津农业科学》2001,7(2):36-37

介绍了平菇菌种津平 90的特征特性、生长条件及其高产栽培技术。  相似文献   

Rotation and Magnetism of Earth's Inner Core   总被引：1，自引：0，他引：1  

GA Glatzmaier  PH Roberts 《Science (New York, N.Y.)》1996,274(5294):1887-1891

Three-dimensional numerical simulations of the geodynamo suggest that a super- rotation of Earth's solid inner core relative to the mantle is maintained by magnetic coupling between the inner core and an eastward thermal wind in the fluid outer core. This mechanism, which is analogous to a synchronous motor, also plays a fundamental role in the generation of Earth's magnetic field.  相似文献   

原子吸收分光光度法测定植物中微量元素的研究   总被引：3，自引：1，他引：3  

高淑云 《农业科学与技术》2008,9(2):6-9

采用原子分光光度法测定牛蒡、银杏、银杏叶和大蒜中Se、Cd、Pb含量,以期为该法用于植物微量元素测定提供参考。  相似文献