全文获取类型
收费全文 | 137篇 |
免费 | 15篇 |
专业分类
林业 | 3篇 |
农学 | 1篇 |
4篇 | |
综合类 | 16篇 |
农作物 | 2篇 |
水产渔业 | 6篇 |
畜牧兽医 | 113篇 |
园艺 | 2篇 |
植物保护 | 5篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 1篇 |
2014年 | 8篇 |
2013年 | 34篇 |
2012年 | 3篇 |
2011年 | 2篇 |
2010年 | 13篇 |
2009年 | 7篇 |
2008年 | 3篇 |
2007年 | 3篇 |
2006年 | 4篇 |
2005年 | 7篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 8篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 7篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1978年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有152条查询结果,搜索用时 15 毫秒
81.
SAA Butler NJ Phillips GB Boe‐Hansen GA Bo BM Burns K Dawson MR McGowan 《Reproduction in domestic animals》2012,47(3):463-471
The primary objective of this study was to investigate the impact of animal‐level factors including energy balance and environmental/management stress, on the ovarian function of Bos indicus heifers treated to synchronize ovulation. Two‐year‐old Brahman (BN) (n = 30) and BN‐cross (n = 34) heifers were randomly allocated to three intravaginal progesterone‐releasing device (IPRD) treatment groups: (i) standard‐dose IPRD [Cue‐Mate® (CM) 1.56 g; n = 17]; (ii) half‐dose IPRD [0.78 g progesterone (P4); CM 0.78 g; n = 15]; (iii) half‐dose IPRD + 300 IU equine chorionic gonadotrophin at IPRD removal (CM 0.78 g + G; n = 14); (iv) and a control group, 2× PGF2α [500 μg prostaglandin F2α (PGF2α)] on Day ?16 and ?2 (n = 18). Intravaginal progesterone‐releasing device‐treated heifers received 250 μg PGF2α at IPRD insertion (Day ?10) and IPRD removal (Day ?2) and 1 mg oestradiol benzoate on Day ?10 and ?1. Heifers were managed in a small feedlot and fed a defined ration. Ovarian function was evaluated by ultrasonography and plasma P4 throughout the synchronized and return cycles. Energy balance was evaluated using plasma insulin‐like growth factor 1 (IGF‐I) and glucose concentrations. The impact of environmental stressors was evaluated using plasma cortisol concentration. Heifers that had normal ovarian function had significantly higher IGF‐I concentrations at commencement of the experiment (p = 0.008) and significantly higher plasma glucose concentrations at Day ?2 (p = 0.040) and Day 4 (p = 0.043), than heifers with abnormal ovarian function. There was no difference between the mean pre‐ovulatory cortisol concentrations of heifers that ovulated or did not ovulate. However, heifers that ovulated had higher cortisol concentrations at Day 4 (p = 0.056) and 6 (p = 0.026) after ovulation than heifers that did not ovulate. 相似文献
82.
83.
84.
MC Esteso MR Fernández-Santos AJ Soler V Montoro A Quintero-Moreno JJ Garde 《Reproduction in domestic animals》2006,41(3):241-246
Computer-automated sperm-head morphometry was used in this study to determine the effects of cryopreservation on red deer sperm-head morphometry. Epididymal sperm samples were collected from 40 mature stags and were divided. One portion was diluted at room temperature in a Tris-citrate egg yolk medium, containing 6% glycerol. A microscope slide was prepared from single extended sperm samples prior to freezing. The remainder of each sample was frozen in nitrogen vapours. After thawing, sperm smears were prepared as described above. All slides were air dried and stained with Hemacolor. The sperm-head dimensions for length, width, area, perimeter and shape factor (length/width), for a minimum of 135 spermatozoa were determined for each slide by means of the Sperm-Class Analyser (SCA). Firstly, our results show that cryopreservation substantially reduced (p < 0.001) sperm motility and plasma membrane and acrosome integrities. In addition, sperm heads were significantly smaller in cryopreserved spermatozoa than in the companion extended samples for area (32.05 microm2 vs 32.56 microm2; p < 0.05), length (8.46 microm vs 8.53 microm; p < 0.0001) and shape factor (1.833 vs 1.849; p < 0.0001) for all stags. These differences were found within 29 of 40 stags (75%) for at least three of the morphometric parameters. The individual variability (CV) of sperm head measurements from extended samples was negatively correlated (p < 0.005) with the per cent of change in sperm head measurements after cryopreservation for area (r = -0.465), width (r = -0.483) and perimeter (r = -0.375). Thus, the lower the sperm head variability in the extended samples, the greater the sperm change as a consequence of the cryopreservation. These results suggest that the variability (heterogeneity) in sperm head dimensions of individual stags may be a good indicator of sperm freezability. 相似文献
85.
Saccharomyces cerevisiae var. boulardii preserves the integrity of intestinal mucosa in gilthead seabream,Sparus aurata subjected to a bacterial challenge with Vibrio anguillarum
下载免费PDF全文
![点击此处可从《Aquaculture Research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
86.
RE Dunin-Borkowski MR McCartney RB Frankel DA Bazylinski M Posfai PR Buseck 《Science (New York, N.Y.)》1998,282(5395):1868-1870
Off-axis electron holography in the transmission electron microscope was used to correlate the physical and magnetic microstructure of magnetite nanocrystals in magnetotactic bacteria. The magnetite crystals were all single magnetic domains, and the magnetization directions of small superparamagnetic crystals were constrained by magnetic interactions with larger crystals in the chains. Shape anisotropy was found to dominate magnetocrystalline anisotropy in elongated crystals. A coercive field between 300 and 450 oersted was determined for one chain. 相似文献
87.
The microbiological quality of water, sediments and seafood products of three Sicilian marine fish farms (Castellammare Gulf, Capo d'Orlando and Porto Palo) was investigated in order to draw a complete picture of the health conditions from the start (environment) to the end (seafood product) of the productive cycle. Before the beginning of fish farming, low concentrations of faecal contamination indicators (faecal coliforms, Escherichia coli, enterococci) were found in the water of each examined area. Due to the enhanced organic load released from cages, the set‐up of fish farming significantly altered the distribution of faecal indicators and sometimes that of halophilic vibrios in the pelagic compartment. Significant differences in the density of heterotrophic bacteria were sometimes recorded at the sediment level. Despite this increase in microbial abundance, the microbiological conditions remained acceptable for the productive process. Pathogens (Salmonella spp., Vibrio parahaemolyticus, Listeria monocytogenes, Staphylococcus aureus) were mostly absent in seafood products. The study underlines that the achievement of good quality levels in aquaculture strongly depends on the conformity of the rearing environment to qualitative microbiological standards, highlighting the importance of sanitary controls along the different steps of the productive cycle. 相似文献
88.
Australian bat lyssavirus (ABLV) is a member of the Lyssavirus genus of the Rhabdoviridae family and is found in Australian bat species. It is of public health concern because of the rabies-like syndrome it causes in humans, resulting in government health and wildlife agencies using varied communication approaches to inform targeted audiences about zoonotic risks associated with handling bats. Despite these warnings, the number of reports of human-bat interactions remains high. This paper details a survey conducted to analyse the approaches utilised by a range of stakeholders to educate and communicate warnings to their target audiences. The survey focused on identifying the target audiences, communication methods used, along with the message frequency, content, and perceived effectiveness. Analysis of the top three messages delivered by stakeholders revealed that over half were information-focused messages and over a third, instruction-focused. Stakeholders identified the need to balance messaging about bat handling risks with information regarding the vulnerable status of bats and their environmental significance. Whilst the most common and (perceived) effective method of communication was one-on-one discussions, it was also identified to be ineffective for targeting mass audiences leading stakeholders to recognise the need to adapt to more efficient means of communication. The outcomes of this study may be useful to improve risk communication strategies regarding ABLV in Australia. 相似文献
89.
CASE HISTORY: Nine of 24 captive kiwi treated with oral levamisole at a dose between 25–43 mg/kg showed signs of respiratory distress. Six died within 4 h of treatment and the remaining three made a full recovery within 24 h. CLINICAL AND PATHOLOGICAL FINDINGS: Within 3–4 h of treatment, the affected birds had an elevated respiratory rate, mucoid nasal discharge and rapidly became comatose. Post mortem examination revealed accumulation of thick mucus in the oral cavity and trachea. There was severe pulmonary congestion and oedema and early bronchopneumonia in the lungs of five of the birds. In two birds, there was acute hepatic degeneration and necrosis and one bird had acute pancreatic degeneration and necrosis. DIAGNOSIS: Acute levamisole toxicity. CLINICAL RELEVANCE: Kiwi were acutely sensitive to levamisole toxicity at doses that are well within the safe range for domestic poultry. Levamisole should not be used as an anthelmintic in kiwi. 相似文献
90.
AC Johnstone BI Davidson AR Roe MR Eccles RD Jolly 《New Zealand veterinary journal》2013,61(5):307-314
AIM: To describe the pathology and inheritance of a congenital polycystic kidney disease (PKD) of sheep. METHODS: Mode of inheritance of PKD was investigated by evaluation of results of the disorder from planned matings in two consecutive years within subsets of a flock that had a high prevalence of PKD in lambs. Gross pathological and histopath- ological studies were based on tissues derived from this study. Haematoxylin and eosin (H&E)-stained paraffin sections of kidney, liver, extrahepatic biliary and pancreatic ducts, pancreas and epididymis were used to describe the lesions. RESULTS: Twenty-five lambs affected by PKD, of both sexes, were born, numbers in accord with those expected for an autosomal recessive disorder in the population studied. In all cases for which tissues were available, the renal, bile ductal (intrahepatic and extrahepatic), pancreatic and epididymal tissues had widespread dysplastic changes and associated cyst formation. CONCLUSIONS: The findings of renal cysts in conjunction with cysts in other organs are unifying features in many of the human and animal forms of PKD and suggest a related pathogenic and genetic base consistent with an autosomal recessive disorder. 相似文献