全文获取类型
收费全文 | 762篇 |
免费 | 52篇 |
专业分类
林业 | 59篇 |
农学 | 19篇 |
149篇 | |
综合类 | 22篇 |
农作物 | 47篇 |
水产渔业 | 76篇 |
畜牧兽医 | 374篇 |
园艺 | 11篇 |
植物保护 | 57篇 |
出版年
2024年 | 2篇 |
2023年 | 4篇 |
2022年 | 26篇 |
2021年 | 63篇 |
2020年 | 55篇 |
2019年 | 50篇 |
2018年 | 43篇 |
2017年 | 40篇 |
2016年 | 46篇 |
2015年 | 20篇 |
2014年 | 37篇 |
2013年 | 52篇 |
2012年 | 55篇 |
2011年 | 57篇 |
2010年 | 29篇 |
2009年 | 26篇 |
2008年 | 42篇 |
2007年 | 38篇 |
2006年 | 26篇 |
2005年 | 25篇 |
2004年 | 33篇 |
2003年 | 11篇 |
2002年 | 17篇 |
2001年 | 2篇 |
2000年 | 8篇 |
1999年 | 2篇 |
1992年 | 1篇 |
1990年 | 3篇 |
1972年 | 1篇 |
排序方式: 共有814条查询结果,搜索用时 187 毫秒
171.
Maciel Laura Priscila Araújo Amaro de Carvalho Francisco Fernando Ramos Batista Ângela Maria Vieira Guim Adriana do Vale Maciel Michel Cardoso Daniel Barros de Lima Júnior Dorgival Morais 《Tropical animal health and production》2019,51(6):1717-1723
Tropical Animal Health and Production - The objective of this study was to evaluate the effect of the substitution of Tifton 85 hay (Cynodon spp.) with spineless cactus (Nopalea cochenillifera) on... 相似文献
172.
Fbio S. Mendona Ricardo Z. Vaz Fabiano N. Vaz Willian S. Leal Isabella D. B. Silveira Joo Restle Arione A. Boligon Fernando F. Cardoso 《Animal Science Journal》2019,90(2):288-296
This study aimed to assess preslaughter factors responsible for the occurrence of bruises to front, rib, loin, hip, and round sites of cattle carcasses. Data from the slaughter of 148 loads of cattle were assessed, totaling 4,611 carcasses. Evaluated bruising factor variables were animal gender, journey distance (km), vehicle type (m²), journey time (hours), load density (kg/m2), handling and facilities conditions (optimal, acceptable, and unacceptable), and unloading waiting time (min). Gender had the strongest influence on carcass bruising, being the first variable to enter in the majority of models related to the carcass sites. Female carcasses displayed higher bruising in all sites. Densities above 401 kg/m² caused more bruising. With the exception of the loin, unacceptable, and acceptable conditions assigned to farm facilities and handling resulted in higher average bruising. Articulated vehicles with a greater load capacity were more likely to cause bruising. The effects of variables causing bruises act differently in the various carcass sites. In this sense, the results of this study suggested possible management practices for specific problems during the preslaughter period to minimize losses by bruising to different carcass sites. 相似文献
173.
Luisa Samaniego-Barrón Sarahí Luna-Castro Carolina Pi?a-Vázquez Francisco Suárez-Güemes Mireya de la Garza 《Veterinary research》2016,47(1)
Mannheimia haemolytica is a Gram negative bacterium that is part of the bovine respiratory disease, which causes important economic losses in the livestock industry. In the present work, the interaction between M. haemolytica A1 and bovine lactoferrin (BLf) was studied. This iron-chelating glycoprotein is part of the mammalian innate-immune system and is present in milk and mucosal secretions; Lf is also contained in neutrophils secondary granules, which release this glycoprotein at infection sites. It was evidenced that M. haemolytica was not able to use iron-charged BLf (BholoLf) as a sole iron source; nevertheless, iron-lacked BLf (BapoLf) showed a bactericidal effect against M. haemolytica with MIC of 4.88 ± 1.88 and 7.31 ± 1.62 μM for M. haemolytica strain F (field isolate) and M. haemolytica strain R (reference strain), respectively. Through overlay assays and 2-D electrophoresis, two OMP of 32.9 and 34.2 kDa with estimated IP of 8.18 and 9.35, respectively, were observed to bind both BapoLf and BholoLf; these OMP were identified by Maldi-Tof as OmpA (heat-modifiable OMP) and a membrane protein (porin). These M. haemolytica BLf binding proteins could be interacting in vivo with both forms of BLf depending on the iron state of the bovine.
Electronic supplementary material
The online version of this article (doi:10.1186/s13567-016-0378-1) contains supplementary material, which is available to authorized users. 相似文献174.
175.
Maria Cristina Ferrarini Nunes Soares Hage Rejane dos Santos Sousa Davi Siqueira Chaves Raduan Hage Francisco Leonardo Costa de Oliveira Mailson Renan Borges Dias Natalia Sato Minami Anna Carolina Mazeto Ercolin Carolina Fortes Cirimbelli Enrico Lippi Ortolani 《Anatomia, histologia, embryologia》2019,48(2):110-116
The purpose of this work was to determine a radiographic standard of normality for lateral and medial ungulae in 3‐year‐old bovine females of the Nellore breed. Twenty‐six cows underwent radiographic exposure of the medial and lateral ungulae of the hindlimbs and forelimbs; abaxioaxial projections were used. The images were analyzed; distances were measured between the dorsal surface of the distal phalanx and the surface of the hoof capsule. The two angles formed, i.e., an angle between the dorsal surface of the distal phalanx and a line parallel to the sole (inner), and an angle between the dorsal surface of the hoof and a line parallel to the sole (outer), were also recorded. The results suggested a standard of normality for the proximal, middle and distal distances of the ungulae of the forelimbs: 0.96 ± 0.12 cm. For the measurement of hindlimbs, except for the distal distances of the side ungulae, the suggested value was 1.02 ± 0.14 cm; for the distal measurement of the lateral ungulae of the hindlimbs, the value was 1.09 ± 0.12 cm. For inner and outer angles, the values were 36.45° ± 4.4° for the medial ungulae of the forelimbs and 42.50° ± 3.8° for other ungulae of the forelimbs and hindlimbs (standard deviations of the values suggested for the angles should be used as variations between different animals, limbs and ungulae; they should not be used between angles of the same ungula). 相似文献
176.
Emilio A. Martinez Cristina A. Martinez Josep M. Cambra Carolina Maside Xiomara Lucas Jose L. Vazquez Juan Maria Vazquez Jordi Roca Heriberto Rodriguez‐Martinez Maria Antonia Gil Inmaculada Parrilla Cristina Cuello 《Reproduction in domestic animals》2019,54(Z4):4-13
Commercial embryo transfer (ET) has unprecedented productive and economic implications for the pig sector. However, pig ET has been considered utopian for decades mainly because of the requirements of surgical techniques for embryo collection and embryo deposition into recipients, alongside challenges to preserve embryos. This situation has drastically changed in the last decade since the current technology allows non‐surgical ET and short‐ and long‐term embryo preservation. Here, we provide a brief review of the improvements in porcine ET achieved by our laboratory in the past 20 years. This review includes several aspects of non‐surgical ET technology and different issues affecting ET programmes and embryo preservation systems. The future perspectives of ET technology are also considered. We will refer only to embryos produced in vivo since they are the only type of embryos with possible short‐term use in pig production. 相似文献
177.
Evandro Ferreira Cardoso Juarez Lopes Donzele Rita Flávia Miranda de Oliveira Donzele Bruna Leite Sufiate Amanda Dione Silva Tarciso Tizziani 《Tropical animal health and production》2018,50(2):317-325
Two trials were conducted to determine the non-phytate phosphorus (nPP) requirement for broiler under heat stress. In both trials, birds were distributed in a completely randomized 4 × 2 factorial design with four nPP concentrations: 0.25, 0.35, 0.45, and 0.55%, and two Ca supply techniques: Ca fixed at 0.899% (CaF) or varying along with nPP aiming a 2:1 Ca to nPP ratio (CaV). Both trials had eight pens/treatment, with nine and five birds/pen for exp. 1 and exp. 2, respectively. nPP concentration had no effect on feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR), nor fat deposition ratio (FDR). nPP levels showed a linear effect on protein deposition ratio (PDR) only for CaF diets. The nPP levels had a significant effect, regardless the technique adopted, on tibia phosphorus (TibP), which varied quadratically, on tibia calcium (TibCa) that increased quadratically and linearly, respectively, on CaF and CaV diets, and on tibia ash (TibAsh) that showed a quadratic effect for both. No effect was observed on Ca to P ratio in the tibia (TibCa:TibP). The nPP levels showed a linear increase effect over phosphorus intake (PI), phosphorus excreted (PE), and phosphorus retained (PR), and a linear decrease effect on phosphorus retention coefficient (PRC). Therefore, the nPP requirement for broilers from 8 to 21 days of age that provided better performance and bone variables were 0.250 and 0.484%, respectively, for CaF diets and 0.250 and 0.511%, respectively, for CaV diets. 相似文献
178.
179.
Carolina Meira Fabiola B. Joerger Annette P.N. Kutter Andreas Waldmann Simone K. Ringer Stephan H. Böehm Samuel Iff Martina Mosing 《Veterinary anaesthesia and analgesia》2018,45(2):145-157
Objective
To compare the efficacy of three continuous positive airway pressure (CPAP) interfaces in dogs on gas exchange, lung volumes, amount of leak during CPAP and rebreathing in case of equipment failure or disconnection.Study design
Randomized, prospective, crossover, experimental trial.Animals
Ten purpose-bred Beagle dogs.Methods
Dogs were in dorsal recumbency during medetomidine–propofol constant rate infusions, breathing room air. Three interfaces were tested in each dog in a consecutive random order: custom-made mask (M), conical face mask (FM) and helmet (H). End-expiratory lung impedance (EELI) measured by electrical impedance tomography was assessed with no interface (baseline), with the interface only (No-CPAP for 3 minutes) and at 15 minutes of 7 cmH2O CPAP (CPAP-delivery). PaO2 was assessed at No-CPAP and CPAP-delivery, partial pressure of inspired carbon dioxide (PICO2; rebreathing assessment) at No-CPAP and the interface leak (ΔPleak) at CPAP-delivery. Mixed-effects linear regression models were used for statistical analysis (p < 0.05).Results
During CPAP-delivery, all interfaces increased EELI by 7% (p < 0.001). Higher ΔPleak was observed with M and H (9 cmH2O) in comparison with FM (1 cmH2O) (p < 0.001). At No-CPAP, less rebreathing occurred with M (0.5 kPa, 4 mmHg) than with FM (1.8 kPa, 14 mmHg) and with H (1.4 kPa, 11 mmHg), but also lower PaO2 was measured with M (9.3 kPa, 70 mmHg) than with H (11.9 kPa, 90 mmHg) and FM (10.8 kPa, 81 mmHg).Conclusions and clinical relevance
All three interfaces can be used to provide adequate CPAP in dogs. The leak during CPAP-delivery and the risk of rebreathing and hypoxaemia, when CPAP is not maintained, can be significant. Therefore, animals should always be supervised during administration of CPAP with any of the three interfaces. The performance of the custom-made M was not superior to the other interfaces. 相似文献180.
Adrin Lpez‐Porras Carolina Elizondo Aida J. Chaves Alvin C. Camus Matt J. Griffin Kirsten Kenelty Samantha Barum Elías Barquero‐Calvo Esteban Soto 《Journal of the World Aquaculture Society》2019,50(3):645-658
Edwardsiella spp., Streptococcus spp., and Francisella noatunensis subsp. orientalis are some of the most important fish pathogens affecting global tilapia, Oreochromis spp., aquaculture. In Costa Rica, the aquaculture industry is dominated by freshwater‐cultured Nile tilapia, Oreochromis niloticus, which are raised in all seven national provinces. At present, little is known regarding the diversity of pathogens present in these facilities, and definitive identification of agents associated with disease outbreaks are rare. To evaluate the prevalence of common bacterial pathogens in these systems, this study used multiplex quantitative polymerase chain reaction (qPCR) assays targeting Edwardsiella, Streptococcus, and Francisella species as a diagnostic and surveillance tool. In 2017, seven different tilapia hatcheries were visited, and 350 fingerlings were subjected to necropsy and molecular diagnostic evaluation. Fish exhibiting gross signs of disease were subjected to histological and microbiological analysis. For the first time, Edwardsiella anguillarum was recovered and molecularly confirmed from diseased tilapia in Costa Rica. In addition, F. noatunensis subsp. orientalis was identified in a region of Costa Rica where it had not been previously reported. 相似文献