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131.
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
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133.
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
134.
We have detected dozens of previously unknown, moderate earthquakes beneath large glaciers. The seismic radiation from these earthquakes is depleted at high frequencies, explaining their nondetection by traditional methods. Inverse modeling of the long-period seismic waveforms from the best-recorded earthquake, in southern Alaska, shows that the seismic source is well represented by stick-slip, downhill sliding of a glacial ice mass. The duration of sliding in the Alaska earthquake is 30 to 60 seconds, about 15 to 30 times longer than for a regular tectonic earthquake of similar magnitude. 相似文献
135.
136.
Rotation and Magnetism of Earth's Inner Core 总被引:1,自引:0,他引:1
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
137.
为探究不同有机肥对高寒地区燕麦草产量及土壤肥力的影响,本试验共设置 5 个不同的施肥处理,生育期 120 d后测定了燕麦鲜草产量和干草产量,并分析了土壤的理化性质。试验结果表明:不同的有机肥对高寒地区燕麦草产量影响较大,燕麦鲜草产量结合播种施 1 号燕麦专用有机肥作基肥,在分蘖期追施 2 号燕麦专用有机肥处理组最高,为 82 000 kg/hm2,本试验生产的有机肥处理组次之。此外,经土壤化学性质检测,各处理组有机质含量均较施肥前有所增加,本试验生产的有机肥处理组有机质、全氮、全磷、全钾含量最高,说明以牛羊粪为原料通过益生菌发酵自制的有机肥可以有效提高土壤肥力水平。 相似文献
138.
日粮中添加油料籽实对奶牛生产性能及乳脂脂肪酸组成的影响 总被引:4,自引:0,他引:4
本文旨在研究在日粮中添加油料籽实对中国荷斯坦奶牛乳脂肪酸组成及生产性能的影响,为提高奶牛乳脂中共轭哑油酸(CLA)含量,改善乳品质寻找合适的途径.试验选取16头泌乳前期(62±11)d、胎次一致(3胎)、泌乳量相近的中国荷斯坦奶牛,随机分为4组(对照组、菜籽组、亚麻籽组、葵花籽组),每组4头.试验共进行40 d(预试期10 d,正试期30 d),分别在正试期第1天、第15天和第30天测定乳产量、分析乳成分,用气相色谱仪分析乳脂肪酸组成.结果表明,与对照组相比,日粮中添加油料籽实,显著提高了奶牛的泌乳性能(P<0.05),降低了乳脂率(P<0.05),对乳中其他常规成分影响差异不显著(P>0.05);日粮中添加葵花籽后乳脂中CLA含量提高98.28%(P<0.05).菜籽组、亚麻籽组、葵花籽组的乳脂中C14:0和C16:0的含量分别比对照组降低了17.86%和26.75%、15.99%和27.18%、21.99%和21.74%.乳脂中多不饱和脂肪酸(PUFA)含量分别比对照组提高40.83%、47.06%和41.52%(P<0.05).乳脂中的t11-C18:1(x)与CLA(y)的比例(%)存在正相关性,y=0.34x 0.20,R<'=0.696 2(P<0.01).日粮中添加植物油籽显著提高了乳脂中CLA、PUFA的比例,降低了C14:0和C16:0的比例,改善了乳脂的构成,提高了乳品质. 相似文献