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   192篇
  免费   29篇
  国内免费   11篇
林业   1篇
农学   3篇
综合类   31篇
水产渔业   1篇
畜牧兽医   196篇
  2024年   2篇
  2023年   1篇
  2022年   20篇
  2021年   32篇
  2020年   13篇
  2019年   21篇
  2018年   11篇
  2017年   9篇
  2016年   5篇
  2015年   12篇
  2014年   5篇
  2013年   13篇
  2012年   12篇
  2011年   12篇
  2010年   8篇
  2009年   9篇
  2008年   6篇
  2007年   4篇
  2006年   3篇
  2005年   4篇
  2004年   2篇
  2003年   5篇
  2002年   2篇
  2001年   3篇
  2000年   1篇
  1997年   2篇
  1996年   2篇
  1995年   1篇
  1994年   1篇
  1993年   3篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1988年   2篇
  1987年   1篇
  1986年   2篇
排序方式: 共有232条查询结果,搜索用时 62 毫秒
51.
试验旨在建立广灵驴成纤维细胞库,以期在细胞水平上对广灵驴进行保护。本研究以1月龄广灵驴耳缘皮肤组织为试验材料,采用组织块贴壁法进行成纤维细胞培养,建立了广灵驴耳缘皮肤组织成纤维细胞系,并对其相关生物学特性进行了鉴定。结果发现,试验所建立的广灵驴成纤维细胞系大多数细胞呈长梭形,部分细胞呈三角状或星型。在培养过程中,广灵驴原代成纤维细胞在贴壁4 d时开始有细胞从组织边缘游离出来,贴壁14 d后,细胞汇合率达到80%,可以进行第一次传代培养;细胞生长态势良好,生长曲线呈典型的S型曲线;细胞冻存复苏后活率有所下降,但生长状态良好。细胞分裂中期染色体数2n=62,说明成功建立了广灵驴成纤维细胞系。通过本方法建立的广灵驴成纤维细胞系为后续广灵驴的相关研究奠定了基础。  相似文献   
52.
疆岳驴体重和体尺性状的相关和回归分析   总被引:1,自引:0,他引:1  
疆岳驴是我国优良的乳肉兼用地方品种,为了加快对疆岳驴的选育、提纯复壮和保种速度,本研究选择101头疆岳驴进行体重和体尺测定,并应用R语言(2.15.0)进行相关和回归分析。结果表明,年龄对疆岳驴的体高、胸围和体重影响极显著(P<0.001),对体长和管围影响显著(P<0.05),其中1~3岁年龄组的体高、体长、胸围、管围和体重值最大,并且1~3岁公驴的体高、管围和体重显著优于母驴(P<0.05)。疆岳驴的体重与体尺性状有极显著的相关关系(P<0.001),通过建立最优回归方程表明,影响体重的重要性状依次为胸围、体高和体长。建议疆岳驴在选育、提纯复壮和保种时应加大对胸围、体高和体长的选择力度,同时参照最优回归模型可以获得较好的效果。  相似文献   
53.
ObjectivesTo evaluate the cardiorespiratory and biochemical effects of ketamine-propofol (KP) or guaifenesin-ketamine-xylazine (GKX) anesthesia in donkeys.Study designProspective crossover trial.AnimalsEight healthy, standard donkeys, aged 10 ± 5 years and weighing 153 ± 23 kg.MethodsDonkeys were premedicated with 1.0 mg kg?1 of xylazine (IV) in both treatments. Eight donkeys were administered ketamine (1.5 mg kg?1) and propofol (0.5 mg kg?1) for induction, and anesthesia was maintained by constant rate infusion (CRI) of ketamine (0.05 mg kg?1 minute?1) and propofol (0.15 mg kg?1 minute?1) in the KP treatment. After 10 days, diazepam (0.05 mg kg?1) and ketamine (2.2 mg kg?1) were administered for induction, and anesthesia was maintained by a CRI (2.0 mL kg?1 hour?1) of ketamine (2.0 mg mL?1), xylazine (0.5 mg mL?1) and guaifenesin (50 mg mL?1) solution. Quality of anesthesia was assessed along with cardiorespiratory and biochemical measurements.ResultsAnesthetic induction took longer in GKX than in KP. The induction was considered good in 7/8 with KP and in 6/8 in GKX. Anesthetic recovery was classified as good in 7/8 animals in both treatments. Xylazine administration decreased heart rate (HR) in both treatments, but in KP the HR increased and was higher than GKX throughout the anesthetic period. Respiratory rate was higher in GKX than in KP. PaO2 decreased significantly in both groups during the anesthetic period. Glucose concentrations [GLU] increased and rectal temperature and PCV decreased in both treatments. Arterial lactate [LAC] increased at recovery compared with all time points in KP. [GLU] and calcium were higher in GKX than in KP at recovery.Conclusion and clinical relevanceThese protocols induced significant hypoxemia but no other cardiorespiratory or metabolic changes. These protocols could be used to maintain anesthesia in donkeys, however, they were not tested in animals undergoing surgery.  相似文献   
54.
Embryo production in donkeys is inefficient compared with that in other livestock. Obtaining a sufficient number of MII oocytes is the first step to solving this problem. In this study, the number, morphology and maturation rates of cumulus-oocyte complexes (COCs) obtained from abattoir-derived ovaries or live jennies were compared. The diameter of follicles from abattoir-derived ovaries was measured and divided into group 1 (2–6 mm), group 2 (6–10 mm), group 3 (10–20 mm), group 4 (20–28 mm) and group 5 (>28 mm). The results showed that the number of follicles per ovary in group 2 (3.6 ± 0.28) and 3 (4.2 ± 0.90) was higher than that in the other groups (p < .05). The recovery rate in group 3 was higher than group 1 (48.8% vs. 26.8%, p = .00), but lower than group 5 (48.8% vs. 76.5%, p = .025). The percentage of grade A COCs in group 3 was higher than group 2 (59.3% vs. 39.5%, p = .00) and group 1 (59.3% vs. 26.7%, p = .00). Moreover, the percentage of grade A COCs in group 4 (55.0%, p = .710) and group 5 (46.2%, p = .351) was reduced compared with that in group 3. From the above results, the developing follicles (group ovum pick-up [OPU], 10–20 mm) and preovulation follicles (group OPU-Preov, >35 mm) were aspirated from live jennies using OPU. Although there was no difference in the recovery rates of COCs between group 3 and OPU (48.8% vs. 43.0%, p = .184), the percentage of grades A COCs in group OPU was higher than group 3 (72.5% vs. 59.3%, p = .036). There was no difference in the maturation rate between group 3 and OPU (60.3% vs. 69.3%, p = .171) after the COCs matured in vitro. The rates of recovery (72.2%) and maturation (92.3%) in group OPU-Preov were higher than those in other groups (p < .05). Moreover, the effects of maturation time and serum type on maturation rates were evaluated in groups B44 (44 h, FBS), B36 (36 h, FBS) and D44 (44 h, foetal donkey serum, FDS). These results indicated that the maturation rate in group B36 was lower than group B44 (13.1% vs. 47.0%, p = .00) and group D44 (13.1% vs. 53.3%, p = .00). In conclusion, the quality of donkey COCs from OPU was higher than that from abattoir-derived ovaries, the suitable time of donkey in vitro maturation (IVM) was 44 h, and FBS could be replaced with FDS in donkey IVM medium.  相似文献   
55.
56.
Donkeys have evolved to thrive on highly fibrous, poor quality foodstuffs and have evolved as browsers as well as grazers. As such, they have different nutrient requirements with significantly lower energy and protein needs when compared with horses. Dietary management of donkeys is essential when kept in a temperate climate as they are prone to obesity and related disorders. A diet based on fibrous forages and limited grazing is usually sufficient for the majority of donkeys and mules. Specialist feeding is discussed in this article.  相似文献   
57.
马、驴精液的保存与应用技术发展速度相对较慢,文幸从马、驴精液的采集,处理,稀释,冷冻,解冻,授精等几个方面就目前国内外发展情况进行了概述.  相似文献   
58.
Laparoscopic sterilization of Sardinia donkeys using an endoscopic stapler   总被引:1,自引:0,他引:1  
OBJECTIVE: To describe a laparoscopic technique for sterilization of the male donkey using an endoscopic linear stapler (ELS). STUDY DESIGN: Clinical report. ANIMALS: Male Sardinia donkeys (n=6), aged 24-36 months. METHODS: Laparoscopic sterilization was performed under standing sedation or recumbent under general anesthesia. An endoscopic linear stapler was used to transect, and control hemorrhage of, the spermatic cord. Serum testosterone concentrations were measured preoperatively and at 3, 6, and 12 months after sterilization. One testis from each of 2 donkeys was collected at 12 months for histologic examination. RESULTS: Sterilization was successfully achieved. The only minor intraoperative complication experienced was hemorrhage from 1 spermatic cord stump, which was re-stapled. No other major short- or long-term complications occurred. Serum testosterone concentrations were < 15 ng/dL at 3, 6, and 12 months after surgery in all donkeys. Testicular atrophy without evidence of revascularization was observed in the 2 testes examined histologically. CONCLUSIONS: Sterilization of descended testes by intraabdominal laparoscopic transection of the spermatic cord is a simple practical method, with minimal intraoperative or postoperative complications. Testicular revascularization did not occur. CLINICAL RELEVANCE: Laparoscopic sterilization in donkey can be performed using an endoscopic linear stapler as an alternative to scrotal castration.  相似文献   
59.
六个家驴品种mtDNA D—Loop部分序列的遗传多样性分析   总被引:1,自引:0,他引:1  
对中国的6个家驴品种(关中驴、德州驴、庆阳驴、泌阳驴、广灵驴、晋南驴)利用PCR-SSCP技术分析了其mtDNA D-Loop部分序列的遗传多样性。87个个体共检测到19个单倍型,单倍型比例为21.8%。单倍型多样度以关中驴、晋南驴较高,分别为0.834和0.904;其次为泌阳驴和广灵驴,分别为0.629、0.529;德州驴和庆阳驴较低,分别为0.467、0.599。文章从分子水平上揭示了家驴的遗传多样性,为我国家驴品种资源的评价和利用提供了一些依据。  相似文献   
60.
REASON FOR PERFORMING STUDY: Donkey dental disorders are being recognised with increased frequency worldwide and have important welfare implications; however, no detailed investigations of dental disorders in donkeys appear to have been published. OBJECTIVES: To determine the prevalence of specified dental disorders in donkeys by performing a prospective post mortem study on donkeys that were subjected to euthanasia or died for other reasons at the Donkey Sanctuary, UK. METHODS: Post mortem examinations were performed on 349 donkeys over an 18 month period, 2005-2006. The presence and extent of specified dental disorders were recorded and these data analysed to determine their prevalence and common locations. RESULTS: A high prevalence (93%) of disorders was noted in the population with a median age of 31 years. In particular, cheek teeth diastemata (85% prevalence) were very common, often associated with advanced periodontal disease. Other disorders observed included missing teeth (in 55.6% of donkeys), displaced teeth (43%), worn teeth (34%), local overgrowths (15%), focal sharp overgrowths (3%) and dental-related soft tissue injuries (8%). CONCLUSIONS AND POTENTIAL RELEVANCE: Aged donkeys have a high prevalence of significant dental disease, especially cheek teeth diastemata. These findings highlight the importance of routine dental examinations and prophylactic dental treatments to improve the dental health and welfare of donkeys.  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