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41.
This study was conducted to examine the effect of ethanolic ginger (Zingiber officinale) extract on growth performance and some skin mucus immune parameters in rainbow trout (Oncorhynchus mykiss). A total of 600 rainbow trout fingerling (10.07 ± 0.21 g) were randomly assigned to four groups in triplicate and fed for 45 days with 1, 2.5 and 5 g kg?1 of ginger extract and with unsupplemented basal diet as the control. The total protein content and lysozyme, alkaline phosphatase and protease activities of skin mucus were investigated following 15, 30 and 45 days of feeding. Results showed that administration of 2.5 and 5 g kg?1 of ethanolic ginger extract for 45 days improved weight gain, feed utilization efficiency and feed conversion ratio of O. mykiss (P < 0.05). Significantly higher (P < 0.05) skin mucus lysozyme, alkaline phosphatase and protease activity and protein level were observed in the 2.5 and 5 g kg?1 ginger extract groups on the 30th and 45th day compared to the controls. The findings suggest that ethanolic extract of ginger enhances growth performance and skin mucus immune parameters of rainbow trout.  相似文献   
42.
This study aimed to compare the efficacy of dietary α-tocopherol with that of dl-α-tocopheryl acetate, both either alone or in combination with vitamin C (ascorbic acid), on the growth performance, survival, and stress resistance of angelfish, Pterophylum scalare, juveniles. Juveniles were fed ad libitum for four weeks with Artemia enriched with no vitamins (control), vitamin C (Tc), α-tocopherol (Tα), dl-α-tocopheryl acetate (T dl ), α-tocopherol and vitamin C (Tα+C), and dl-α-tocopheryl acetate and vitamin C (T dl+C). After four weeks, an osmotic stress test was performed using seawater (25 g/L) to evaluate juvenile’s resistance to stress. Whole-body glucose and cortisol were used as stress indicators. At the end of the feeding trial, growth performance and survival of the juveniles fed vitamin-enriched Artemia were significantly (< 0.05) higher than for the control fish. Best performance was recorded for the Tα+C group. Survival, however, was not significantly (P > 0.05) different between the vitamin-fed groups. Osmotic stress significantly elevated the stress indicators, whole-body cortisol and glucose levels (P < 0.05), highest and lowest values being observed in control and Tα+C groups, respectively. Survival after osmotic stress of juveniles fed the Tα+c diet was significantly higher (by 46.2%, P < 0.001) than for controls. Results suggested that α-tocopherol has greater efficacy than dl-α-tocopheryl acetate and enriching Artemia with α-tocopherol and vitamin C together improves growth performance, survival, and stress resistance of angelfish juveniles.  相似文献   
43.
The Penman–Monteith equation (PM) is widely recommended because of its detailed theoretical base. This method is recommended by FAO as the sole method to calculate reference evapotranspiration (ETo) and for evaluating other methods. However, the detailed climatological data required by the Penman–Monteith equation are not often available especially in developing nations. Hargreaves equation (HG) has been successfully used in some locations for estimating ETo where sufficient data were not available to use PM method. The HG equation requires only maximum and minimum air temperature data that are usually available at most weather stations worldwide. Another method used to estimate ETo is the artificial neural network (ANN). Artificial neural networks (ANNs) are effective tools to model nonlinear systems and require fewer inputs. The objective of this study was to compare HG and ANN methods for estimating ETo only on the basis of the temperature data. The 12 weather stations selected for this study are located in Khuzestan plain (southwest of Iran). The HG method mostly underestimated or overestimated ETo obtained by the PM method. The ANN method predicted ETo better than HG method at all sites.  相似文献   
44.
Efficacy of Thymus vulgaris essential oils was assessed on growth, immune response and disease resistance of rainbow trout (Oncorhynchus mykiss). Fish weighing 10 g were fed with dietary supplemented of the oils at 0.5, 1.0 and 2.0 ml/kg feed for 2 months. Fish fed with the oils at 0.5 ml/kg feed demonstrated a better weight gain and specific growth rate, compared to other treatments (p < .05). Fish fed with 1.0 ml the oils showed the highest up‐regulation of complement component 3 (C3) and (cluster of differentiation 4) (CD4) genes expression (p < .05), while lysozyme gene expression level significantly increased in fish fed with 2.0 ml of the oils. In addition, at the end of the experiment, the expression of C3 and CD4 genes were significantly up‐regulated in fish fed with 1.0 and 2.0 ml of the oils, while IL‐1ß and lysozyme genes expression levels were significantly decreased in fish fed 2.0 ml oils, towards the end of the trial (p < .05). There was a fluctuation in the levels of Alanine aminotransferase, Aspartate aminotransferase and Alkaline phosphatase in all treatments during the experiment. When treated fish were challenged with Aeromonas hydrophila, the highest survival rate was observed in 0.5 ml/kg treatment, followed by 2 and 1 mg/kg treatments. Overall, these findings demonstrated that dietary administration of T. vulgaris oils especially at 0.5 mg/kg feed can be considered as a potential component for enhancing of the growth, immune responses and disease resistance of trout against motile Aeromonas septicemia caused by A. hydrophila.  相似文献   
45.
The outer membrane protein of Aeromonas hydrophila is a potential candidate for vaccine development. In this study, after cloning and expression of ompTS, 270 common carp, weighing 44 ± 5.7 g divided into five groups, were injected intraperitoneally twice with 3‐week intervals. Groups included the following: PBS, PBS plus Freund's adjuvant, recombinant protein, recombinant protein plus Freund's adjuvant and 20 fish as negative control. Two weeks after the second injection, 30 fish of each group were challenged with a dose of 2 × LD50 of Aeromonas hydrophila and RPS was measured. The antibody level was measured using ELISA test. The protection of recombinant protein in the immunized fish with and without adjuvant, respectively, was about 82.61% and 78.26% (the protection of recombinant protein electroeluted from an SDS–PAGE with and without adjuvant, respectively, was about 78.62% and 69.57%). The average of antibody level in recombinant protein with and without adjuvant was significantly higher than the PBS group (p < .05). The ability of recombinant ompTS to increase the antibody level and to protect the fish from challenge by A. hydrophila demonstrated that recombinant ompTS protein injection can be used to immunize common carp against A. hydrophila infection.  相似文献   
46.
This study investigates the dietary arachidonic acid (ARA) requirement from juvenile to maturation stage in an anabantid model fish, the blue gourami, Trichopodus trichopterus. Specifically we determined the optimum dietary ARA content to maximize juvenile growth and subsequent sexual maturation and to improve the quality of their eggs and offspring. Five experimental diets containing 0.02, 0.53, 1.05, 1.60, and 2.12% ARA (of dry weight) were fed to juveniles over 5 mo. The results showed that whole‐body fatty acid profile of broodstock significantly changed in fish fed diets of different ARA content (ANOVA, P < 0.003). The highest contents of 18:2n‐6 and Σn‐6 were obtained in fish fed 0.53% ARA, and a decreasing trend was observed with elevated dietary ARA levels. Monthly specific growth rate (SGR) measurements revealed significant differences in the juvenile stage, but the SGR of broodstock was unaffected by dietary ARA. Protein and ash content of whole‐body broodstock showed no differences among groups, while lipid content decreased as ARA levels increased. Maximum volume of the oocyte was obtained in the 1.05% ARA group, while the yolk sac size increased as dietary ARA increased. The optimum growth and survival of the larvae produced by broodstock were recorded in the 2.12 and 1.6% ARA groups, respectively. It was concluded that despite the presumed ability of freshwater fish to synthesize and meet their highly unsaturated fatty acid requirements, dietary ARA higher than 1.05% had significant stimulatory effects on growth of juveniles but no obvious influence on the growth of matured fish. Also, higher ARA levels (1.6–2.12%) were found to improve the quality of eggs and offspring.  相似文献   
47.
Abstract

A significant part of potentially mineralizable organic nitrogen (N) in soil comprises microbial cells (Bonde et al. 1988). Since the major part of organic N in cow dung also consists of microbial biomass N (Marsh and Campling 1970), it may be worth comparing the origin and the successive processes of N mineralisation in cow dung with those in soil. We studied the effect of the dung beetle, Onthophagus lenzii H., on the decomposition of cow dung and found that the dung beetle played a significant role in this process (Yokoyama et al. 1990). We employed, here, the acid hydrolysis method to analyze the effect of the dung beetle on N transformation in dung balls and residual cow dung.  相似文献   
48.
1. The objective of this study was to determine the prevalence and antimicrobial resistance of Arcobacter spp. isolated from different species of retail poultry meat in Iran.

2. From August 2012 to April 2013, a total of 540 raw poultry meat samples from chicken (n = 100), turkey (n = 100), quail (n = 100), partridge (n = 80), duck (n = 50), ostrich (n = 60) and geese (n = 50) were purchased from randomly selected retail outlets in Shahrekord, Isfahan, Sari and Rasht, Iran.

3. Using culture techniques, 71 of 540 poultry meat samples (13.1%) were positive for Arcobacter spp. The highest prevalence of Arcobacter spp. was found in chicken meat (28.0%), followed by quail (12.0%), duck (11.4%), turkey (11.0%), geese (8.0%), partridge (7.5%) and ostrich (3.3%) meat. The number of A. butzleri isolated from poultry meat samples (90.1%) was significantly higher than A. cryaerophilus (7.1%) and A. skirrowii (2.8%). Significantly more poultry meat samples were found to contain Arcobacter spp. by the PCR assay than by the culture method.

4. Susceptibilities of Arcobacter isolates were determined for 14 antimicrobial drugs using the disk diffusion method. All of the 71 Arcobacter isolates tested were resistant to one or more antimicrobial agents. Resistance to cephalothin and vancomycin (95.8%) was the most common finding, followed by resistance to methicillin, azithromycin and ampicillin. All Arcobacter isolates were susceptible to gentamicin, streptomycin, tetracyclin and kanamycin.

5. The results of this study indicated the importance of poultry meat, especially chicken meat, as potential sources of Arcobacter spp. infection in people. Furthermore, the strains indicated resistance to a broad spectrum of antibiotics.  相似文献   

49.
Journal of Plant Diseases and Protection - The honey bee (Apis mellifera), as one of the most important pollinating insects, plays a critical role in biodiversity conservation and global food...  相似文献   
50.
The larger the bulk density of the soil, the smaller the saturated hydraulic conductivity (Ks), however, the relationship between Ks and dry bulk density for tilled and untilled conditions is different. Ks is lower in tilled soil than in untilled soil with the same texture at the same bulk density. The purpose of this study was to compare different models for the prediction of Ks for two soil textures under both tilled and non-tilled conditions. We compred two models based on the non-similar media concept (NSMC-0, NSMC-1), a model based on the similar media concept (SMC) and a model based on the Kozeny equation and Poiseuille law for prediction of Ks (KC-1 and KC-2). This study was conducted at two areas with loam and silty clay loam soils under tilled and untilled conditions. It is concluded that the SMC model is not able to predict Ks under either tilled or untilled conditions. Further, the NSMC-0 model, along with an equation to estimate the shape factor, was able to predict Ks versus dry bulk density for tilled soils. According to our study, under untilled conditions, the KC-1 and NSMC-1 models, and under tilled conditions, the NSMC-1 and NSMC-0 models, predicted Ks accurately. It is concluded that the NSMC models together with the optimized Kozeny–Carman models could reliably be used to predict Ks in different soil textures.  相似文献   
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