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During a previous longitudinal study, performed on four farrow-to-finish farms (A to D), samples were taken from twelve sows, their offspring, and the environment on various occasions over six months to study the MRSA presence. During the present study, a selection of the obtained MRSA isolates were typed by multiple-locus variable-number tandem-repeat analysis (MLVA), Pulsed Field Gel Electrophoresis (PFGE), spa typing, and SCCmec typing to study the genetic diversity of LA-MRSA isolates and to determine possible MRSA sources for pig(let)s. PFGE, spa typing, and SCCmec typing revealed the presence of one or few dominant genotype(s) per farm. In contrast, 212 MLVA types were detected on the four farms, forming one cluster on farm A, three on farm B, four on farm C and two on farm D. The genotype, found on farm A was unique for this farm. Farms B, C and D shared one cluster. In general, MLVA types from these clusters were isolated from piglets, sows, and the environment on various sampling events. Piglets carried MLVA types both related and unrelated to their mother sows’ MLVA types at farrowing and onwards. In conclusion, molecular typing revealed that within a farm one or a few dominant strain(s) are widespread. Potential MRSA sources for piglets were mother sows, the environment and other piglets.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0089-4) contains supplementary material, which is available to authorized users.  相似文献   
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Studies of earthworm species and their activity, expressed as channels, on cultivated loamy (Humic Cryaquept) and clayey soils (Typic Endoaqualf and Typic Cryaquept) were conducted in southern and central Norway before conversion from conventional to organic cropping systems. At all the three study areas: Landvik (Grimstad), Voll (Ås) and Kvithamar (Stjørdal), the earthworm species Aporrectodea caliginosa, Aporrectodea rosea, Allolobophora chlorotica and Lumbricus rubellus were found. At Landvik, where the deep-burrowing species Aporrectodea longa, A. caliginosa and Lumbricus terrestris dominated, medium (4–6 mm) and coarse (>6 mm) earthworm channels were most numerous below the plough layer. Almost no coarse pores were found at Voll and Kvithamar. The volume of earthworm channels below the plough layer was 0.6–0.8% of total soil volume at Landvik and Voll and 0.3–0.4% at Kvithamar. Earthworm channels >6 mm below the plough layer were useful to identify present and previous activity of deep-burrowing earthworms such as L. terrestris. Below the plough layer, roots were almost entirely restricted to earthworm channels and interaggregate spaces.  相似文献   
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The efficacy of diclazuril against intestinal and hepatic coccidiosis was studied in artificially infected rabbits. Prophylaxis against intestinal coccidiosis was evaluated using a mixed infection of Eimeria intestinalis, Eimeria magna and Eimeria perforans. Continuous medication in the feed at 1 p.p.m. was 100% effective in reducing oocyst output and faecal scores, and weight gain and feed efficiency were normal. Hepatic coccidiosis induced by Eimeria stiedai was prevented at 0.5 and 1 p.p.m. as shown by negative oocyst counts, normal liver weight, absence of liver lesions, and normal body-weight gain and feed efficiency. Medication at 1 p.p.m. for 7 consecutive days during the prepatent phase of hepatic coccidiosis resulted in large reductions in oocyst counts and lesion scores with a normal liver weight and growth performance. Diclazuril at 1 p.p.m. in the feed prevented both intestinal and hepatic coccidiosis in rabbits and can be advocated for safe mass medication.  相似文献   
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Eighteen chickens were immunized subcutaneously with purified type 1 fimbriae from Salmonella enterica serotype Enteritidis at 18 and 21 weeks of age. Evidence of IgG and IgA responses was found in the eggs and in the sera of the immunized hens. Three weeks later, immunized and non-immunized chickens (n=18) were challenged intravenously with 2x10(7) live Salmonella enterica serotype Enteritidis. There was no significant difference in the numbers of eggs laid by immunized and non-immunized birds. The percentage of Salmonella contaminated eggs was significantly higher in the non-immunized group than in the immunized group due to a higher percentage of contamination of the externally disinfected egg shells. There were no statistical differences in the percentages of contaminated yolks and egg whites between control and immunized birds. No differences in the number of colonizing bacteria could be found in the spleen nor in the liver between the immunized and the control groups throughout the experiment. Salmonella was cleared from the ovary of the immunized birds in the second week p.i., in contrast to the control birds where Salmonella was isolated till the third week after infection. Oviducts were significantly more infected in the control group than in the immunized group. Salmonella was cleared from the oviducts at 3 weeks p.i. in the immunized hens but not in the control hens. In conclusion, we demonstrated that the immunization of laying hens with type 1 fimbriae reduced the number of contaminated eggs and reduced the colonization of the reproductive organs.  相似文献   
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Mycobacterium marinum, M. fortuitum and M. chelonae are the etiological agents of fish mycobacteriosis. Fish mycobacteriosis is a disseminated infection reported in more than 150 fish species and is usually accompanied by emaciation and death over a period of months to years. Granulomas are formed both externally and scattered throughout the internal organs. Treatment is in most cases unsatisfactory and the overall recommendation is to destroy the diseased stock, particularly since these pathogens are capable of affecting man as well as fish. Especially fish handlers and aquarium hobbyists are infected and the disease is mostly confined to the superficial, cooler body tissues, most often the extremities. Dissemination is apparently rare but has been reported.  相似文献   
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At rabbit flock level, two types of Staphylococcus aureus infections can be distinguished. In the first type, caused by low virulence strains, the infection remains limited to a small number of animals. The second type of infection is caused by the high virulence strains, which spread throughout the rabbitry. The pathogenetic capacity of a particular S. aureus strain is attributed to a combination of extracellular factors and invasive properties such as adherence and biofilm formation. Twenty eight high virulence and 34 low virulence S. aureus isolates recovered from rabbits between 1998 and 2003 were used to study slime production on Congo red Agar (CRA) and prevalence of bap, icaA and icaD associated with biofilm formation. Furthermore these strains were screened for the presence of bbp, clfA, clfB, cna, ebpS, eno, fnbA, fnbB and fib encoding microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). The presence of icaA and icaD was not correlated with slime production on CRA. Bap was absent in all strains. All rabbit S. aureus strains harboured clfA and clfB. The prevalences of ebpS, eno, fnbA and fib did not reveal striking differences between high and low virulence strains. FnbB prevalence in high virulence isolates was lower than in low virulence isolates and cna was absent in high virulence strains. It was remarkable that only high virulence strains were positive for bbp. Further research is necessary to elucidate the significance of bbp in the pathogenesis of high virulence strains.  相似文献   
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