全文获取类型
收费全文 | 198篇 |
免费 | 25篇 |
专业分类
林业 | 13篇 |
农学 | 12篇 |
36篇 | |
综合类 | 12篇 |
农作物 | 6篇 |
水产渔业 | 30篇 |
畜牧兽医 | 106篇 |
植物保护 | 8篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 8篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 14篇 |
2017年 | 9篇 |
2016年 | 16篇 |
2015年 | 15篇 |
2014年 | 5篇 |
2013年 | 18篇 |
2012年 | 9篇 |
2011年 | 9篇 |
2010年 | 8篇 |
2009年 | 8篇 |
2008年 | 5篇 |
2007年 | 7篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2004年 | 7篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 8篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 7篇 |
1988年 | 2篇 |
1985年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有223条查询结果,搜索用时 15 毫秒
51.
SE RIDGE JT HARKIN† ‡ RT BADMAN† AM MELLOR§ JWA LARSEN¶ 《Australian veterinary journal》1995,72(4):150-153
SUMMARY: Johne's disease was diagnosed in 10 alpacas ( Lama pacos ) in Australia between February 1993 and May 1994. Eight of the animals were between 12 and 24 months of age, one was a 6-year-old female, and one was a 4-year-old male. Five, including the 6-year-old and the 4-year-old alpacas, showed weight loss and diarrhoea before death or slaughter. The other cases showed no clinical signs of Johne's disease but 4 gave a positive result on faecal culture and one gave a positive result on testing with the caprine ACID assay and had acid-fast organisms in its faeces. At necropsy, all cases had grossly enlarged mesenteric lymph nodes. Johne's disease was diagnosed after histological examination of the lymph nodes with conventional culture and polymerase chain reaction testing of tissue samples. This report outlines the clinical, epidemiological, and pathological findings in these cases. 相似文献
52.
Effects of Dietary Supplementation of β‐hydroxy‐β‐methylbutyrate on Sow Performance and mRNA Expression of Myogenic Markers in Skeletal Muscle of Neonatal Piglets
下载免费PDF全文
![点击此处可从《Reproduction in domestic animals》网站下载免费的PDF全文](/ch/ext_images/free.gif)
HF Wan JT Zhu Y Shen X Xiang HJ Yin ZF Fang LQ Che Y Lin SY Xu B Feng D Wu 《Reproduction in domestic animals》2016,51(1):135-142
The effects of dietary β‐hydroxy‐β‐methylbutyrate (HMB) supplementation during gestation on reproductive performance of sows and the mRNA expression of myogenic markers in skeletal muscle of neonatal pigs were determined. At day 35 of gestation, a total of 20 sows (Landrace × Yorkshire, at third parity) were randomly assigned to two groups, with each group receiving either a basal diet or the same diet supplemented with 4 g/day β‐hydroxy‐β‐methylbutyrate calcium (HMB‐Ca) until parturition. At parturition, the total and live litter size were not markedly different between treatments, however, the sows fed HMB diet had a decreased rate of stillborn piglets compared with the sows fed the control (CON) diets (p < 0.05). In addition, piglets from the sows fed HMB diet tended to have an increased birth weight (p = 0.08), and a reduced rate of low birth weight piglets (p = 0.05) compared with piglets from the CON sows. Nevertheless, lower feed intake during lactation was observed in the sows fed the HMB diet compared with those on the CON diet (p < 0.01). The relative weights of the longissimus dorsi (LD) and semitendinosus (ST) muscle were higher (p < 0.05) in neonatal pigs from the HMB than the CON sows. Furthermore, maternal HMB treatment increased the mRNA levels of the myogenic genes, including muscle regulatory factor‐4 (MRF4, p < 0.05), myogenic differentiation factor (MyoD) and insulin‐like growth factor‐1 (IGF‐1, p < 0.01). In conclusion, dietary HMB supplementation to sows at 4 g/day from day 35 of gestation to term significantly improves pregnancy outcomes and increases the expression of myogenic genes in skeletal muscle of neonatal piglets, but reduces feed intake of sows during lactation. 相似文献
53.
Evaluation of a fibrate,specific stimulant of PPARα, as a therapeutic alternative to the treatment of clinical ovine pregnancy toxaemia
下载免费PDF全文
![点击此处可从《Journal of veterinary pharmacology and therapeutics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
S. Da Silva L. G. Cal‐Pereyra A. Benech J. Acosta‐Dibarrat M. J. Martin M. C. Abreu S. Perini J. R. González‐Montaña 《Journal of veterinary pharmacology and therapeutics》2016,39(5):497-503
Ovine pregnancy toxaemia is a metabolic disorder affecting sheep in their last 6 weeks of pregnancy as a result of their inability to maintain adequate energy homoeostasis. Different alternative treatments are available with variable results. The aim of this research was to evaluate a peroxisome proliferator‐activated receptor alpha (PPARα) stimulant as an alternative to treat clinical pregnancy toxaemia. Thirty‐three adult sheep, with known gestation date and carrying a single foetus, were fasted from day 130 of gestation until animals showed clinical disease. From that moment onwards, sheep were treated during 6 days with three different therapeutic alternatives: 10 mg/kg of 2‐methyl‐2‐phenoxy‐propionic acid; 10 mg/kg of 2‐methyl‐2‐phenoxy‐propionic acid + 100 mL of propylene glycol oral; or 100 mL of propylene glycol oral. Glycaemia and serum β‐hydroxybutyrate (BHOB) were determined daily. Liver biopsies were taken at day 130 of gestation, at the beginning and end of treatments and at 5 days postpartum, evaluating the extent and degree of the steatosis lesion. Even though in sheep treated with 2‐methyl‐2‐phenoxy‐propionic acid, serum concentrations of glucose and BHOB recovered more slowly, we conclude that 2‐methyl‐2‐phenoxy‐propionic acid alone or combined with propylene glycol can be used as an alternative to effectively treat fatty liver, and therefore pregnancy toxaemia. 相似文献
54.
Daniele Soares Barroso Neves Robério Rodrigues Silva Fabiano Ferreira da Silva Laize Vieira Santos George Abreu Filho Sinvaldo Oliveira de Souza Marceliana da C. Santos Weder Jansen Rocha Ana Paula Gomes da Silva Mateus de Melo Lisboa Maria Magna Silva Pereira Venício Macedo Carvalho 《Tropical animal health and production》2018,50(7):1411-1416
The aim of this study was to evaluate the effect of increasing concentrate supplementation levels on the intake, nutrient digestibility, and performance of crossbred steers during the dry period of the year. The experiment was developed on Princesa do Mateiro farm, in the municipality of Ribeirão do Largo, located in the southwest region of Bahia State, Brazil. Forty uncastrated male crossbred (½ Holstein-Zebu) steers with an average body weight (BW) of 232.55?±?24.97 kg were distributed into four treatments in a completely randomized design with ten replicates. The animals were managed in an experimental area formed by Brachiaria brizantha cv. Marandu, in an intermittent grazing system. Treatments consisted of the following supplementation levels: 0.2% BW, with 60% crude protein (CP); 0.3% BW, with 40% CP; 0.4% BW, with 30% CP; and 0.5% BW, with 24% CP. The intakes of forage dry matter in kg/day and %BW and neutral detergent fiber corrected for ash and protein (NDFap) in %BW decreased linearly, whereas the intake of non-fibrous carbohydrates corrected for ash and protein in kg/day and average daily gain increased linearly. Therefore, the use of supplementation at 0.5% BW (24% crude protein) to provide gains of up to 0.500 kg/day is recommended for grazing steers during the post-weaning period in the dry season of the year. 相似文献
55.
J. Y. P. Palencia M. A. G. Lemes C. A. P. Garbossa M. L. T. Abreu L. J. Pereira M. G. Zangeronimo 《Journal of animal physiology and animal nutrition》2018,102(1):204-213
The use of functional amino acids during pregnancy has been linked to improved reproduction in mammals. In this context, arginine is a precursor in the synthesis of numerous molecules, such as nitric oxide and polyamines, which play an important role during reproduction. However, contradictory studies are found in the literature, particularly regarding the amount of supplementation and the period of pregnancy in which it is used. The objective of this study was to evaluate the effects of dietary arginine supplementation for pregnant sows on foetal development via a systematic review. The search for papers was performed during the month of December 2015, in the databases ISI Web of Science, Science Direct, Scopus, and SciELO. From a total of 5675 returned studies, only 13 papers were selected after applying selection criteria. Most (47%) of the studies that evaluated the effects of dietary arginine supplementation on foetal development in pigs used 1% arginine. Supplementation was initiated in the first third of pregnancy in 47% of tests, including in both primiparous and multiparous sows. These studies showed positive results for embryo survival and foetal development, evidenced by the increase in placental weight and the number and weight of piglets born alive. Of all evaluated studies, 53% showed benefits on foetal development. It is concluded that supplementing dietary arginine in gestating sows can benefit embryo survival and foetal development. However, to establish a supplementation plan with this amino acid, aspects related to the period of pregnancy, supplementation levels, and source of arginine must be well defined. 相似文献
56.
Characterization of rabies post‐exposure prophylaxis in a region of the eastern Amazon,state of Pará, Brazil,between 2000 and 2014
下载免费PDF全文
![点击此处可从《Zoonoses and public health》网站下载免费的PDF全文](/ch/ext_images/free.gif)
57.
58.
Kassio Rios da Silva Wilson Wasielesky Jr. Paulo César Abreu 《Journal of the World Aquaculture Society》2013,44(1):30-41
A study evaluating nitrogen and phosphorus dynamics was carried out using biofloc technology (BFT) systems employed to raise Litopenaeus vannamei juveniles. The study was carried out for 42 d in three fiberglass tanks with 210 L useful volume with no water exchange. Salinity, temperature, dissolved oxygen, pH, nutrients, suspended solids, and chlorophyll‐a were monitored every 3 d. At the completion of the experiment, the shrimp had absorbed 39.1 and 35.0% of the total nitrogen (N) and phosphorus (P) inputs, respectively, while 39.0% of the N and 34.1% of the P remained in the system in dissolved forms. The dominant process of ammonium immobilization in the system was oxidation by nitrifying bacteria. On Day 42, the nitrate concentration represented more than 80% of the total dissolved inorganic nitrogen in all tanks. However, most of the dissolved nitrogen present in the tanks (80%) was organic. Phosphate and organic nitrogen and phosphorus continuously accumulated in the system throughout the experiment. The removal of these nutrients should be the focus of future studies because they may enhance the growth of harmful algae in tanks and in the water bodies that collect the post‐crop wastewater. 相似文献
59.
Campos E Moraes J Façanha AR Moreira E Valle D Abreu L Manso PP Nascimento A Pelajo-Machado M Lenzi H Masuda A Vaz Ida S Logullo C 《Veterinary parasitology》2006,138(3-4):349-357
The present work evaluates the kinetics of utilization of the main potential energy sources throughout the embryonic developmental stages of Boophilus microplus. The embryonic development of this arthropod is completed in 21 days. Cellularization of the blastoderm occurs on the 6th day and is rapidly followed by germ band extension and segmentation, whose first signs are visible on the 7th day. Cellularization is typically a maternal-driven process, carried out by molecular determinants deposited in the oocyte during oogenesis. On the other hand, segmentation is of zygotic nature, being the consequence of the synthesis of various components by the growing embryo. The enhancement in total B. microplus RNA was observed after cellularization, corroborating the replacement of maternal-driven processes by embryonic zygotic expression. An abrupt increase in oxygen consumption was observed from cellularization until the 8th day of development. The reduction in dry weight at the same period and the susceptibility of oxygen consumption to KCN suggest that the respiration process is activated during early embryonic development. A marked decrease in total lipid content occurred between the 5th and 7th days of development, suggesting this is the main energy source for cellularization. A major reduction in carbohydrate content occurred later, between the 7th and 9th days, and it could be assigned to the morphological segmentation of the embryo. Although the total amount of proteins remains unchanged from oviposition to hatching, a 15% reduction in vitellin (VT) content was observed before cellularization, up to the 4th day after egglaying. This observation was correlated to the synthesis of new proteins needed to support early embryo development. Additional 20% of VT was consumed thereafter, mainly at the end of embryogenesis, and in this case VT is probably used as energy source to the older embryo. Altogether, these data indicate different energy sources for maternal and zygotic driven processes. 相似文献
60.