全文获取类型
收费全文 | 393篇 |
免费 | 37篇 |
国内免费 | 25篇 |
专业分类
林业 | 2篇 |
农学 | 11篇 |
7篇 | |
综合类 | 66篇 |
农作物 | 9篇 |
水产渔业 | 38篇 |
畜牧兽医 | 315篇 |
园艺 | 6篇 |
植物保护 | 1篇 |
出版年
2024年 | 2篇 |
2023年 | 5篇 |
2022年 | 9篇 |
2021年 | 19篇 |
2020年 | 10篇 |
2019年 | 18篇 |
2018年 | 17篇 |
2017年 | 13篇 |
2016年 | 8篇 |
2015年 | 17篇 |
2014年 | 20篇 |
2013年 | 32篇 |
2012年 | 20篇 |
2011年 | 19篇 |
2010年 | 15篇 |
2009年 | 20篇 |
2008年 | 19篇 |
2007年 | 18篇 |
2006年 | 23篇 |
2005年 | 14篇 |
2004年 | 9篇 |
2003年 | 11篇 |
2002年 | 12篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 11篇 |
1998年 | 9篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1979年 | 1篇 |
1978年 | 4篇 |
1956年 | 1篇 |
排序方式: 共有455条查询结果,搜索用时 15 毫秒
431.
Gudmundsdóttir S Lange S Magnadóttir B Gudmundsdóttir BK 《Journal of fish diseases》2003,26(6):331-338
Atlantic halibut, Hippoglossus hippoglossus (L.), was shown to be sensitive to infection by three different isolates of Aeromonas salmonicida ssp. achromogenes in pre-challenge tests using intraperitoneal (i.p.) and intramuscular (i.m.) injections as well as bath challenges. A commercial furunculosis vaccine, Alphaject 1200, and an autogenous vaccine, AAS, based on the challenge strain, induced immune protection as shown in challenge tests 8 weeks post-immunization. The survival rate of vaccinated fish after i.p. challenge was 100%, whereas mortality of control fish was 61%. Employing i.m. challenge, relative percentage survival induced by the furunculosis vaccine and the AAS vaccine was 47 and 44, respectively. Mortality of i.m. injected controls was 68%. Vaccinated fish behaved normally following vaccination but the weight gain was significantly reduced in vaccinated fish 8 weeks post-vaccination compared with control fish receiving phosphate-buffered saline. At the same time, intra-abdominal adhesions were observed in fish injected with either of the two vaccines or adjuvant alone. Antibody response against A. salmonicida ssp. achromogenes was detected in sera from fish receiving either vaccine. 相似文献
432.
433.
观察绿脓杆菌的G+B+C三个血清型制备的灭活疫苗大规模接种后的速发接种反应及保护性效果观察.用绿脓杆菌G+B+C三个血清型制备的疫苗以小鼠和水貂为实验室观察组,同时设定阴性对照,观察疫苗免疫后的速发接种反应;在养殖场,选择常年因绿脓杆菌引起的水貂出血性肺炎的养殖户,采用预防免疫和发病期紧急预防接种两种方式,并回访保护效果.在实验室对水貂和小鼠皮下接种疫苗,接种后7~21 d观察接种部位和解剖小鼠检查病理学变化,没有出现任何异常反应.从2012年和2013年共制备的5个批次14万头份的疫苗,在对临床推广应用的回访中,只有一个养殖户少量水貂出现接种部位化脓,经查是由于注射部位的肌肉吸收性降低而引起,对预防接种的10万头份中,接种后没有发生绿脓杆菌引起的出血性肺炎,在对4万头份的由于绿脓杆菌引起出血性肺炎的紧急接种中,在5~10 d达到控制本病的目的.结论:G+B+C三个血清型绿脓杆菌疫苗速发接种反应发生率低,预后良好,无论是预防接种还是发病后紧急接种,均具有较好的保护性. 相似文献
434.
Hatchery-reared Atlantic salmon, Salmo salar L., were vaccinated intraperitoneally (i.p.) with a live attenuated Cryptobia salmositica vaccine (either 100 000 or 5000 parasites fish−1 ) and 4 weeks later were challenged with the parasite (either 100 000 or 5000 parasites fish−1 ). Unvaccinated, infected salmon had high parasitaemias and were anaemic. Fish given a high dose (100 000 parasites fish−1 ) had higher parasitaemias than fish given the lower dose. Vaccinated fish had low parasitaemias and a mild anaemia, but recovered quickly after challenge. Complement-fixing antibody increased in vaccinated fish after challenge and was highest at 2 weeks post-challenge. The cell-mediated response (both T cells and B cells) was depressed in infected fish until 4 weeks after infection. In vaccinated fish, the humoral response (i.e. B-lymphocytes) was greater than the cell-mediated response (i.e. T-lymphocytes). In contrast, infected fish had a greater cell-mediated than humoral immune response. 相似文献
435.
菜籽饼是重要的饲料蛋白质来源,氨基酸组成与饲料营养品质有着密切关系,其中丝氨酸、胱氨酸和酪氨酸为多数动物的半必需氨基酸。本研究利用甘蓝型油菜双单倍体(DH)群体分别与双亲Tapidor和Ningyou 7回交构建的2套BC1F1群体,采用新创建的双子叶作物种子品质性状遗传体系QTL定位软件和作图方法,对油菜籽丝氨酸、胱氨酸和酪氨酸含量进行了种子胚和母体植株2套遗传体系的QTL定位分析。结果表明,在A1、A4、A7、A8、A9、C2、C3和C9染色体上检测到5个丝氨酸含量QTL、2个胱氨酸含量QTL和5个酪氨酸含量QTL,分别解释59.34%、29.66%和59.26%的表型变异。其中5个QTL属于主效QTL,均能解释10%以上的表型变异。全部QTL均具极显著的胚和母体加性主效应,其中3个QTL具显著或极显著的环境互作效应。在A4染色体上发现1个QTL簇,该区域存在3个控制丝氨酸、胱氨酸和酪氨酸含量的QTL。一些重要QTL以及与之紧密连锁的分子标记在今后图位克隆和分子标记辅助选择育种中具有重要的利用价值。 相似文献
436.
低酚棉种仁含油量的母体效应和杂种优势分析 总被引:1,自引:0,他引:1
利用3个低酚棉品种配制的四个正、反交组合的F1、F2和回交世代对棉籽种仁含油量的母体效应和杂种优势进行了遗传分析。结果表明,棉籽的种仁含油量受母体基因型的控制,即存在母体效应,细胞质效应对种仁含油量无显著影响。用种仁含油量高的品种作母本配制的杂种一代(F1)棉籽,其种仁含油量有极显著的中亲和高亲优势,F2棉籽种仁含油量的自交衰退率虽较大,但其中亲优势仍较大,且优于用低种仁含油量品种作母本配制的杂种二代(F2)棉籽。利用杂种优势是提高棉籽种仁含油量的有效方法,其中的关键是亲本选配。此外,本文还讨论了棉籽含油量遗传研究的模型选择问题和提高棉籽含油量的育种方法问题。 相似文献
437.
L. Dybjær A. N. W. Olsen F. Møller K. H. Jensen 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(2):134-141
This study investigated the effects of housing farrowing sows in either crates (C-sows) or a get-away system (G-sows) until day 11 after farrowing on the subsequent behaviour in multi-suckling pens. Emphases were placed on nursing behaviour patterns of relevance for the piglets' growth and survival in the multi-suckling pens. Ten groups of six sows were used. Behaviour was recorded for 24 h on days 1, 8 and 15 after the introduction to the multi-suckling pen. When the sows had farrowed in the get-away system significantly more nursings were initiated in the multi-suckling pen. Furthermore, the G-sows terminated a significantly smaller percentage of the nursings in the multi-suckling pens and there was significantly less cross-suckling compared with pens with C-sows. G-sows also tended (P = 0.08) to lose fewer piglets in the multi-suckling pens than C-sows. In conclusion, the results suggest that nursing behaviour in multi-suckling pens may be improved when the sows farrow in get-away systems as compared with crates. 相似文献
438.
鸡马立克氏病疫苗免疫后的免疫学变化 总被引:1,自引:0,他引:1
实验对1日龄雏鸡接种MD三价疫苗或HVT疫苗后的免疫应答变化进行了检测.发现MD疫苗免疫后:(1)脾脏、胸腺T细胞IL—2诱生活性和IL—2R表达明显增强或增多,表明IL—2的免疫调节作用增强;(2)胸腺、法氏囊和脾脏中T细胞和抗体生成细胞数量及T细胞增殖功能明显增高,表明中枢与外周免疫器官的细胞免疫和体液免疫应答显著增强;(3)盲肠扁桃体、哈德尔腺、支气管粘膜淋巴组织中T细胞和抗体生成细胞数量以及泪液、气管液、肠液、胆汁中IgA,IgG,IgM含量明显增多,表明呼吸道与消化道的局部免疫应答也显著增强;(4)MD三价疫苗免疫鸡的上述免疫应答变化比HVT疫苗免疫鸡明显. 相似文献
439.
本实验以Lasota疫苗点眼、滴鼻免疫21日龄火鸡,研究其盲肠扁桃体、哈德尔腺和支气管粘膜淋巴组织的免疫应答。结果如下:免疫火鸡上述局部免疫组织的浆细胞、酯酶阳性T细胞及淋巴细胞显著增多,巨噬细胞程度不等地增加;盲肠扁桃体淋巴小结增多、增大。这表明,免疫火鸡消化道和呼吸道局部免疫组织不仅体液免疫应答显著加强,而且细胞免疫反应也明显增强。NDD 强毒攻击后,免疫火鸡呼吸道和消化道局部免疫组织的体液免疫和细胞免疫水平进一步升高;对照火鸡则出现细胞免疫和体液免疫机能衰竭。 相似文献
440.
LaSota vaccination may not protect against the lesions of velogenic newcastle disease in chickens 总被引:1,自引:0,他引:1
Two groups of six weeks old cockerels comprising 40 immunized and 40 non-immunized birds were inoculated intramuscularly with
VGF-1, which is a local Nigerian strain of velogenic Newcastle disease virus (VNDV). Immunized birds did not show any clinical
signs except significant loss (p < 0.05) in body weight on days 5 and 20 post inoculation (PI). But the non-immunized birds
showed clinical signs of disease characterized by anorexia and drowsiness from day 2 PI. These were followed on day 3 PI by
depression, diarrhoea, opisthotonus, weight loss (p < 0.05) and high mortalities (96.9%). Both the immunized and non-immunized
groups showed severe atrophy of the bursa, spleen and thymus. Histopathological section of these lymphoid organs showed necrosis
and depletion of lymphocytes. Both the gross and microscopic lesions were more severe in the non-immunized birds. Marked ballooning
degeneration was observed in the bursal follicles of the non-immunized birds. This lesion has not been described earlier for
any other disease and could be diagnostic for VND. Our results also showed that VND can cause marked atrophy of the lymphoid
organs, which may lead to immunosupression without the characteristic signs of Newcastle disease (ND) in vaccinated chickens.
This no doubt emphasizes the limitation of vaccination as a biosecurity measure in poultry industry.
Ezema, W.S., J.O.A. Okoye and Nwanta, J.A., 2008. LaSota vaccination may not protect against the lesions of velogenic Newcastle
disease in chickens. Tropical Animal Health and Production 相似文献