首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   43篇
  免费   10篇
综合类   7篇
畜牧兽医   44篇
植物保护   2篇
  2023年   1篇
  2021年   1篇
  2020年   2篇
  2019年   1篇
  2018年   3篇
  2017年   3篇
  2016年   2篇
  2015年   3篇
  2014年   4篇
  2013年   10篇
  2011年   5篇
  2010年   4篇
  2009年   1篇
  2007年   2篇
  2006年   1篇
  2005年   2篇
  2004年   1篇
  1999年   2篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1990年   1篇
排序方式: 共有53条查询结果,搜索用时 31 毫秒
1.
2.
3.
Three groups of horses and ponies (N = 13, 13 and 12) were treated with ivermectin paste (0.2 mg/kg p.o.), avermectin B1 solution (0.2 mg/kg p.o.), or fenbendazole suspension (10 mg/kg via nasogastric tube). The avermectin B1 was a 1% solution in a propylene glycolglycerol formal base. Faecal strongyle egg counts were performed before, and 14, 28, 42, 56 and 70 d, after treatment. Full-thickness skin biopsies from the neck, pectoral and umbilical regions were examined for Onchocera microfilaria before treatment, and again 14 and 70 d later. Ivermectin therapy produced a significant (P less than 0.01) decrease in mean strongyle egg counts 14, 28, 42 and 56 d after treatment. Avermectin B1 therapy resulted in significant (P less than 0.01) decreases in mean strongyle egg counts 14, 28 and 42 d after treatment. All horses given ivermectin or avermectin B1 had zero strongyle egg counts 14 and 28 d after treatment. Fenbendazole failed to significantly decrease strongyle egg counts. Both ivermectin and avermectin B1 resulted in zero microfilaria counts in all horses 14 d after treatment. On day 70 the percentage decrease in microfilaria counts were 100% and 99.6% respectively. Fenbendazole failed to significantly decrease microfilaria counts. The oral administration of this formulation of avermectin B1 appeared to be highly efficacious against intestinal strongyles and Onchocera microfilaria. The duration of anti-strongyle activity was, however, significantly (P less than 0.01) shorter than that of ivermectin paste.  相似文献   
4.
5.
Objective The aims of this work were to (1) develop a low-cost equine movement tracking collar based on readily available components, (2) conduct preliminary studies assessing the effects of both paddock size and internal fence design on the movements of domestic horses, with and without foals at foot, and (3) describe distances moved by mares and their foals. Additional monitoring of free-ranging feral horses was conducted to allow preliminary comparisons with the movement of confined domestic horses. Procedures A lightweight global positioning system (GPS) data logger modified from a personal/vehicle tracker and mounted on a collar was used to monitor the movement of domestic horses in a range of paddock sizes and internal fence designs for 6.5-day periods. Results In the paddocks used (0.8–16 ha), groups of domestic horses exhibited a logarithmic response in mean daily distance travelled as a function of increasing paddock size, tending asymptotically towards approximately 7.5 km/day. The distance moved by newborn foals was similar to their dams, with total distance travelled also dependent on paddock size. Without altering available paddock area, paddock design, with the exception of a spiral design, did not significantly affect mean daily distance travelled. Feral horses (17.9 km/day) travelled substantially greater mean daily distances than domestic horses (7.2 km/day in 16-ha paddock), even when allowing for larger paddock size. Conclusions Horses kept in stables or small yards and paddocks are quite sedentary in comparison with their feral relatives. For a given paddock area, most designs did not significantly affect mean daily distance travelled.  相似文献   
6.
The effects of beta-glucanase expressed by transformed Lactobacillus strains on growth performance, apparent digestibilities of dry matter and crude protein, and apparent metabolisable energy were studied. Two hundred and forty 1-d-old chicks (Avian-43) were randomly divided into three dietary treatment groups and fed with the following diets: (i) basal diet (control) (BD); (ii) basal diet with parental Lactobacillus strains (BDP) and (iii) basal diet with transformed Lactobacillus strains (BDT). At 21 d of age, the body weight, body weight gain and feed conversion ratio of the BDT-fed chickens were significantly improved. At 14 and 21 d of age, the proportions of dry matter in the duodenum, jejunum, ileum, caeca and excreta of chickens given the BDT diet were significantly higher than those of chickens given the BD and BDP diets. Apparent metabolisable energy, digestibilities of crude protein and dry matter were also significantly improved (by 3.5, 5.6 and 3.5%, respectively) by the BDT diet. These results showed that the transformed Lactobacillus strains improved digestibility as well as enhanced the growth performance of chickens.  相似文献   
7.
8.
While the use of NMR and stable isotopes in metabolism studies is hardly new, it is only recently that isotope-edited NMR spectroscopy has been applied in kinetic studies of glyphosate metabolism of soil microbes. NMR can detect multiple species simultaneously and non-destructively, yielding valuable information on structural identification of metabolites. T riple R esonance I sotope ED ited spectroscopy (TRIED), [2H]NMR, and [2H–13C] INEPT (I nsensitive N ucleus E nhancement through P olarization T ransfer) are three isotope-edited techniques which have been used in combination to examine the microbial degradation of glyphosate (N-phosphonomethylglycine). Using 13C- and 15N-labeled glyphosate, TRIED can detect multiple metabolites in crude matrices at submicrogram levels, an improvement over earlier techniques where milligrams were needed. It can detect 500 nanograms of 13C–15N-labeled compound in a crude sample (1 : 1400 mass ratio), only a few hours work being required. [2H]NMR and [2H–13C]INEPT were also used as complementary techniques to further examine metabolites whose 13C–15N bond has been cleaved. The three-isotope-edited methods produced results consistent with both radioactivity and HPLC analyses. Accordingly, we are able to detect minute levels of metabolites in the presence of complex mixtures, minimizing the costs and time of sample purification. ©1999 Society of Chemical Industry  相似文献   
9.
The full length phytase gene of Mitsuokella jalaludinii was successfully cloned and was found to be 1 047 bp in length, with 348 amino acids, and was designated as PHY7 phytase gene. A comparison of the sequence of PHY7 phytase gene of M. jalaludinii with various microbial phytase gene sequences showed that it was not similar to those from other bacteria except Selenomonas ruminatium, thus suggesting that they may both express a new class of phytase. The PHY7 phytase gene was subsequently subcloned into bacterial expression vector, p ET32 a, for expression in Escherichia coli strain Rosetta-gami. Expression of the recombinant phytase gene was optimised and characterised. The recombinant phytase was estimated to be approximately 55 k Da by SDS-PAGE analysis. The recombinant phytase exhibited optimum activity at 55°C, p H 4.5 and showed good p H stability from p H 3.5 to 5.5(78% relative activity). Metal ions such as Ca2+, Mg2+, and K+ were found to exert significant stimulatory effect on the recombinant phytase activity while Cu2+, Fe3+, and Zn2+ greatly inhibited the enzyme activity. The recombinant phytase showed moderate resistance to trypsin proteolysis, but susceptible to pepsin proteolysis. The results of the study showed that several characteristics of recombinant phytase were slightly different from the native enzyme. Unfavourable characteristics such as reduced p H stability and metal ion effects should be taken into consideration during feed enzyme formulation.  相似文献   
10.
The effect of vaginal administration of misoprostol plus terbutaline sulphate 6 h prior to artificial insemination (AI) upon the site of AI (vaginal or cervical) and fertility was studied using a total of 87 estrous synchronized Serra da Estrela ewes (control n = 42 and treated n = 45). Artificial insemination was performed using refrigerated semen at 54–55 h after sponge removal. Lambing rate (fertility) and prolificacy were compared between control and treated ewes. The effect of the site of semen deposition on fertility was also evaluated. Prolificacy rate was not different between control (1.5) and treated (1.59) ewes. The proportion of cervical AI achieved in control (45.2%) and treated (37.8%) ewes was not significantly different. Overall, fertility was significantly lower in control than in treated ewes (42.9% vs 64.4%; p < 0.04). Fertility following vaginal AI was significantly lower for control for than treated ewes (30.4% vs 60.7%; p < 0.03) but the difference was smaller and not significant for cervical AI (control 57.9% vs 70.6%). It was concluded that vaginal administration of misoprostol plus terbutaline sulphate 6 h prior to artificial insemination did not affect the proportion of cervical inseminations but significantly improved the fertility of treated ewes. Although needing confirmation, it was hypothesized that drugs might have induced local secretory modifications leading to an increase of cervical ability to retain more viable spermatozoa for fertilization.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号