全文获取类型
收费全文 | 156篇 |
免费 | 11篇 |
专业分类
林业 | 1篇 |
4篇 | |
综合类 | 21篇 |
水产渔业 | 1篇 |
畜牧兽医 | 138篇 |
园艺 | 1篇 |
植物保护 | 1篇 |
出版年
2023年 | 2篇 |
2020年 | 1篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 14篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 3篇 |
2007年 | 6篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 12篇 |
1997年 | 4篇 |
1996年 | 10篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 10篇 |
1991年 | 11篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有167条查询结果,搜索用时 15 毫秒
61.
62.
63.
Abstract AIMS: To ascertain the levels of awareness of legislation governing the welfare of cats, and provision of basic care, including vaccination, by cat-owners within two locations in New Zealand. To assess the ability of respondents to differentiate between the terms ‘stray’ and ‘feral’. METHODS: A face-to-face questionnaire, consisting of 12 questions in three sections, was distributed by volunteers within Auckland (n=255) and Kaitaia (n=99) to gather information pertinent to the study's aims. Section 1 covered respondents’ personal details; Section 2, ownership and care of cats, including whether or not the cats were vaccinated against feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV); and Section 3, awareness of legislation and differences between the terms ‘stray’ and ‘feral’. RESULTS: Overall, fewer than half of respondents were aware of the animal welfare legislation within New Zealand or the semantic differences between the terms ‘stray’ and ‘feral’ as they appear in the dictionary. Respondents ≥41 years old, and individuals employed in the animal-related sector, were significantly more likely to be aware of the legislation and make the correct distinction between the terms compared with those aged ≤40, and those working in a non-animal-related profession. A significantly greater percentage of cat-owners (42%) provided care for cats they did not own compared with non-owners (26%). Results also indicated a large majority of cat-owners may consider standard annual vaccinations to include vaccination against FIV and FeLV. CONCLUSION: Dissemination of information about animal welfare legislation is important for the care of cats within New Zealand, and the definitions of the terms ‘stray’ and ‘feral’ need to be more clearly stated in order to prevent confusion. This is especially important when cats may be controlled using lethal measures under different legislative precedents that are not necessarily consistent with one another. CLINICAL RELEVANCE: Veterinary clinics may act as a primary source for the dissemination of information about relevant welfare acts as well as preventative health care, thus improving the welfare of cats. Cat-owners need to be better educated about the diseases covered by annual vaccination. 相似文献
64.
R Manjarin JC Dominguez MJ Castro B Alegre MA Driancourt RN Kirkwood 《Reproduction in domestic animals》2010,45(3):555-557
Gilt oestrus and ovulation responses to injection of a combination of equine chorionic gonadotrophin (eCG) and human chorionic gonadotrophin (hCG) (PG600) can be unpredictable, possibly reflecting inadequate circulating LH activity. The objective of this study was to determine the effect of PG600 followed by supplemental hCG on gilt ovarian responses. In experiment 1, 212 Hypor gilts (160 day of age) housed on two farms in Spain received intramuscular (i.m.) injections of PG600 (n = 47), or PG600 with an additional 200 IU hCG injected either concurrently (hCG‐0; n = 39), or at 24 h (hCG‐24; n = 41) or 48 h (hCG‐48; n = 45) after PG600. A further 40 gilts served as non‐injected controls. Ovulation responses were determined on the basis of initial blood progesterone concentrations being <1 ng/ml and achieving >5 ng / ml 10 d after the PG600 injection. The incidence of ovulating gilts having progesterone concentrations >30 ng/ml were recorded. During the study period, 10% of control gilts ovulated whereas 85–100% of hormone‐treated gilts ovulated. There were no significant differences among hormone groups for proportions of gilts ovulating. The proportions of gilts having circulating progesterone concentrations >30 ng/ml were increased (p ≤ 0.02) in all hCG treated groups compared with the PG600 group. In experiment 2, a total of 76 Hypor gilts at either 150 or 200 days of age were injected with PG600 (n = 18), 400 IU eCG followed by 200 IU hCG 24 h later (n = 20), PG600 followed by 100 IU hCG 24 h later (n = 17), or 400 IU eCG followed by 300 IU hCG 24 h later (n = 21). Blood samples were obtained 10 days later for progesterone assay. There were no effects of treatment or age on incidence of ovulation, but fewer 150‐day‐old gilts treated with PG600 or 400 IU eCG followed by 200 IU hCG had progesterone concentrations >30 ng / ml. We conclude that hCG treatment subsequent to PG600 treatment will generate a higher circulating progesterone concentration, although the effect is not evident in older, presumably peripubertal, gilts. The mechanism involved and implications for fertility remain to be determined. 相似文献
65.
Two vaccines, based on formalin-killed whole cells of toxigenic Pasteurella multocida type D and Bordetella bronchiseptica combined with a partially toxoided cell extract of P multocida, were prepared with Freund's incomplete adjuvant (vaccine 1) or by alum precipitation (vaccine 2). Each was tested for safety and efficacy in reducing the severity of nasal turbinate atrophy and improving the growth rate of pigs in three Western Australian commercial piggeries with endemic atrophic rhinitis. In safety experiments with vaccine 1, no adverse clinical effects were observed in vaccinated sows or their progeny. Piglets receiving vaccine 2 showed no injection site abnormalities, pyrexia or turbinate atrophy. In field trials, vaccine 1 significantly reduced the prevalence of moderate to severe nasal turbinate atrophy (Done score 3 to 5) when used in two piggeries (A and B). Progeny from vaccinated sows in piggery B also grew significantly faster than controls. When vaccine 2 was used in piggery A at a later date and in another piggery (C), growth rate was not improved in either piggery and the prevalence of moderate to severe turbinate atrophy was reduced only in piggery C. 相似文献
66.
67.
Acorn production is one of the most important products in silvopastoral systems in the Mediterranean region. In the present
study we carried out two preliminary trials to analyze the distribution of production over time and the effect of pruning.
The objective was to develop tools to manage this valuable resource within these systems. In the first part of the study,
we analyzed the total acorn production of a holm oak stand, and its seasonal distribution (October–January) over two years
(1997–1998 and 1998–1999) in five sites in the southwest of Spain. Mean total acorn production ranged from 590 to 830 kg ha−1. There was considerable variation between the different sites and years studied, as was expected from studies on other oak
species. A comparison was also made of acorn production, comparing annual acorn production between 40 pruned and 40 non-pruned
trees, for the period 1994–1999. There was an interaction between ‘pruning treatment’ and ‘year’. Pruning, significantly decreased
acorn production in all but two years when production was above the average, whereas production was not affected by pruning
the three years that acorn yield was below the average. The study of acorn production and the analysis of the effect of pruning,
needs to be studied over a longer time period. 相似文献
68.
Neuronal necrosis in budgerigars treated with dimetridazole 总被引:1,自引:0,他引:1
69.
R G Zanoni I M Nauta P Kuhnert U Pauli B Pohl E Peterhans 《Veterinary microbiology》1992,33(1-4):341-351
In order to detect a large spectrum of small ruminant lentiviruses, primers for PCR were chosen in conserved parts of the LTR and GAG genes of Icelandic Visna virus 1514 and of the POL gene of caprine arthritis-encephalitis virus. This set of primers was tested in six different caprine arthritis-encephalitis virus (CAEV)- and Maedi-Visna virus isolates of Dutch, American and Swiss origin. The LTR primers allowed the detection of the corresponding fragments of all isolates. The GAG primers allowed amplification of the corresponding fragments of all but the Swiss Maedi-Visna virus strain OLV. Using the POL primers, one Maedi-Visna- and two caprine arthritis-encephalitis virus strains were detected after one round of amplification. Sequencing of the GAG and POL amplification products and comparison to Icelandic Visna virus and CAEV strain CO revealed total heterogeneity of 38% for the GAG- and 28% for the POL fragment. The virus strains studied fall into two groups which are more closely related to one another than to Icelandic Visna virus. 相似文献
70.
The antibody response of sheep to maedi-visna virus (MVV) infection was studied, using an immunoblotting technique that identified the four major viral structural proteins: the envelope glycoprotein gp135, and internal proteins p25, p16 and p14. In sequential serum samples of two inoculated sheep, antibodies to p25 appeared first, soon followed by antibodies to p16. In two sheep with natural infections, which were sampled with longer intervals, antibodies to p25 and p16 appeared simultaneously. Antibody response to p14, which was weak and inconsistent in most cases, appeared after the p16 response. Antibodies to gp135 were detected in only one sheep and appeared 7 weeks after those to p25. Antibodies to p25 were particularly persistent. Antibody recognition patterns of 21 necropsied sheep with naturally occurring infections were compared. Sheep with lesions lacked antibodies to p14 and p16 and sometimes even p25, although these antibodies had been present in earlier stages of infection. Since the time of onset of lesions was unknown, we could not determine whether this decline in antibody activity occurred before, together with, or after the onset of lesion development. 相似文献