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1.
应用多重PCR检测人工感染鸡呼吸道疾病的研究   总被引:3,自引:0,他引:3  
本文报道了IBV,NDV,ILTV,MG人工感染4周龄SPF鸡和非免疫鸡后,用多重PCR检测试验鸡的咽喉棉拭子和器官组织样品,并与传统的病原分离鉴定,血清学方法进行比较,多重PCR无论是对单一感染病原,还是对两种以上混合感染病原,其敏感性和检测速度都优于传统的鉴别诊断方法,具有较高的实用价值,可以直接应用于临床检测,服务于生产。  相似文献   
2.
Recently we reported elimination of radioactivity from [14C]heptachlor from body stores of lactating ovines, mainly into excreta rather than milk, contrasting sharply with bovines. To further assess heptachlor metabolism and clearance by ovines, 12 fine-wool wether lambs (41 +/- 3 kg) housed in metabolism stalls were fed pelleted alfalfa hay (96%) plus molasses (3%) ad libitum and were dosed i.p. once with [14C]heptachlor (1.643 mg/kg body wt; sp. act. = .89 microCi/mg). Feces and urine were collected separately and quantitatively. Light mineral oil was mixed with feed (5 g/100 g) of six lambs and trans-stilbene oxide, an inducer of biotransformational enzymes, was administered i.p. (4 g/hd initially; 2 g/hd daily thereafter) through 20 d to three lambs given each mineral oil treatment, in 2 x 2 factorial arrangement. Feces, urine, blood, bile and body tissues were assayed for total 14C activity. Radioactivity (heptachlor and [or] metabolites) eliminated into excreta during 21 d amounted to 34 to 36% of dose administered, of which 67% appeared in urine and 33% in feces. Biological half-time for elimination into excreta was 11.3 d [Kel = -.061/d], similar to 11.7 d we reported for lactating ewes. Clearance from blood had T1/2 = 14 d. Neither mineral oil nor trans-stilbene oxide altered rate or route of 14C activity excreted or concentrations of 14C activity in blood. Results confirmed that ovines eliminate heptachlor much more rapidly than bovines.  相似文献   
3.
In a field trial conducted during 1992–93 and 1993–94, the effect of basal (B) nitrogen (N) (45 and 60 kg N ha−1) and foliar application (F) of water (W) or 10 kg N ha−1 and 400 or 600 ppm ethrel (E) (2-Chloro ethyl phosphonic acid) at 70 days after sowing was studied on leaf area index and dry mass at 90 days and pod number per plant, seeds per pod, 1000 seed weight, seed yield, oil content and oil vield at harvest of mustard ( Brassica juncea L. Czern & Coss.) cv. T-59. Recommended basal (B) application of 90 kg N ha (BN90) was used as control. On the basis of 2 year data it was found that basal application of 60 kg N and foliar spray of 10 kg N ha −1 and 600 ppm ethrel gave higher values for growth and yield characteristics and enhanced seed yield and oil yield by 12.5 and 14.8%, respectively over control BN90.  相似文献   
4.
Bluegill absorbed 85% of 1 ppb of endrin from water within 48 hr under static exposure conditions. The absorbed radiocarbon was eliminated linearly with a half-life of about 4 weeks. Analyses of eliminated radioactivity revealed only conjugated metabolites. 12-anti-Hydroxyendrin and 12-syn-hydroxyendrin were tentatively identified by cochromatography using thin-layer chromatography/autoradiography and gas chromatography. These metabolites were also present as conjugates in the fish organs. Seventy-three percent of the absorbed radioactivity recovered from fish extracts was in the form of unchanged endrin.  相似文献   
5.
Objective: To correlate the sodium chloride dosage and the serum sodium concentration to clinical signs, to determine if the dosage of homemade play dough (and, therefore, sodium chloride) is the most reliable way to predict clinical signs and prognosis, and to review previously reported treatment options. Design: Retrospective case series. Animals: Fourteen dogs with a history of homemade play dough ingestion. Procedure: Cases were examined for each animal's signalment including body weight, age, approximate amount of play dough ingested, the estimated sodium chloride dosage, clinical signs, serum sodium concentration, and outcome when available. The literature was reviewed to determine pathophysiology and treatment regimens. Results: Twelve of 14 dogs (86%) that ingested homemade play dough showed clinical signs. Vomiting (9 of 14, 64%), polydipsia, and seizures (4 of 14 each, 29%) were the most common signs followed by polyuria, tremors (3 of 14 each, 21%), and hyperthermia (2 of 14, 14%). The lowest calculated dosage associated with objective clinical signs was 1.9 g/kg. Seizures were reported in all animals with serum sodium levels greater than 180 mEq/L. Conclusions and clinical relevance: Homemade play dough ingestion can be a serious and life‐threatening problem. Many factors can contribute to the toxicity of homemade play dough. This study indicates that the serum sodium concentration is a more reliable indicator of the clinical course of the toxicity rather than the amount of play dough and, therefore, the dosage of sodium chloride ingested. Treatment should be based on a clinical evaluation of the patient and laboratory results, and consists of controlling seizures, reducing serum sodium concentrations slowly, and supportive care.  相似文献   
6.
Brucellosis is a zoonotic disease worldwide distributed and having the economic as well as public health importance. The prevalence of brucellosis among sheep flock having history of abortions was studied. A total of 229 samples comprising of 157 blood and 72 clinical samples (vaginal swabs) were collected from 157 animals. Clinical samples were processed for the isolation of Brucella melitensis. Serum samples (n = 157) were tested by Rose Bengal plate test (RBPT) and i-ELISA. A total of 68 (43.31%) and 104 (66.24%) samples were positive by RBPT and ELISA, respectively. Brucella isolates (n = 2) were recovered from clinical samples. Both isolates demonstrated amplification for bcsp 31 and IS711 genes. On AMOS PCR, both the isolates amplified at 731 bp, i.e., belongs to B. melitensis species. The incidence of B. melitensis in a migratory flock warns the thorough testing and culling of Brucella-infected sheep from the flock on a continuous basis; otherwise, such incidence will be routine and poor farmers will be at a loss.  相似文献   
7.
This study was conducted to evaluate the comparative effect of maggot meal, silkworm meal and mealworm as dietary protein source on the production performance and some aspects of meat quality in broilers. In this regard, maggot meal was reared on chicken offal and poultry waste. Silkworm meal was obtained from silk industry, while mealworm was developed through beetles rearing. A total of 120‐day‐old broiler chicks were randomly divided into four groups where soya bean meal (M0) was replaced with maggot meal (M1), silkworm meal (M2) and mealworm (M3) respectively. Each group was further divided into three replicates. The study was carried out for a period of 5 weeks. Diets containing mealworm significantly reduced overall feed consumption and resulted into higher weight gain (p < .05). Lowest feed conversion ratio (FCR) was recorded for birds fed with mealworm diet (p < .05). Tenderness and juiciness of meat were higher (p < .05) in M3 compared to the control and other treatments. Mortality did not vary between the control and the treated groups. Therefore, it is concluded that insect meal is rich in essential nutrients and could be successfully used in broiler ration without compromising acceptability. In the light of this study, mealworm is the best choice in broiler ration, in comparison with maggot and silkworm.  相似文献   
8.
The present study assesses the effects of 5‐aminolevulinic acid (ALA, 0, 0.1, 1 and 10 mg l?1) on the growth of oilseed rape (Brassica napus L. cv. ZS758) seedlings under water‐deficit stress induced by polyethylene glycol (PEG 6000, 0 and ?0.3 MPa). Water‐deficit stress imposed negative effects on seedling growth by reducing shoot biomass, cotyledon water potential, chlorophyll content and non‐enzymatic antioxidants (glutathione and ascorbic acid) levels. On the other hand, water‐deficit stress enhanced the malondialdehyde (MDA) content, reactive oxygen species (ROS) production, enzymatic antioxidants activities, reduced/oxidized glutathione ratio (GSH/GSSG) and reduced/oxidized ascorbic acid (ASA/DHA) ratio in seedlings. Application of ALA at lower dosages (0.1 and 1 mg l?1) improved shoot weight and chlorophyll contents, and decreased MDA in rape seedlings, whereas moderately higher dosage of ALA (10 mg l?1) hampered the growth. The study also indicated that 1 mg l?1 ALA improved chlorophyll content, but reduced MDA content and ROS production significantly under water‐deficit stress. Lower dosages of ALA (0.1 and 1 mg l?1) also enhanced GSH/GSSG and ASA/DHA as compared to the seedlings under water‐deficit stress. The antioxidant enzymes (ascorbate peroxidase, peroxidase, catalase, glutathione reductase and superoxide dismutase) enhanced their activities remarkably with 1 mg l?1 ALA treatment under water‐deficit stress. It was also revealed that 1 mg l?1 ALA treatment alone induced the expression of APX, CAT and GR substantially and under water‐deficit stress conditions ALA treatment could induce the expression of POD, CAT and GR to a certain degree. These results indicated that 0.1–1 mg l?1 ALA could enhance the water‐deficit stress tolerance of oilseed seedlings through improving the biomass accumulation, maintaining a relative high ratio of GSH/GSSG and ASA/DHA, enhancing the activities of the specific antioxidant enzymes and inducing the expression of the specific antioxidant enzyme genes.  相似文献   
9.
Genome-wide association studies (GWAS) are useful to facilitate crop improvement via enhanced knowledge of marker-trait associations (MTA). A GWAS for grain yield (GY), yield components, and agronomic traits was conducted using a diverse panel of 239 soft red winter wheat (Triticum aestivum) genotypes evaluated across two growing seasons and eight site-years. Analysis of variance showed significant environment, genotype, and genotype-by-environment effects for GY and yield components. Narrow sense heritability of GY (h 2  = 0.48) was moderate compared to other traits including plant height (h 2  = 0.81) and kernel weight (h 2  = 0.77). There were 112 significant MTA (p < 0.0005) detected for eight measured traits using compressed mixed linear models and 5715 single nucleotide polymorphism markers. MTA for GY and agronomic traits coincided with previously reported QTL for winter and spring wheat. Highly significant MTA for GY showed an overall negative allelic effect for the minor allele, indicating selection against these alleles by breeders. Markers associated with multiple traits observed on chromosomes 1A, 2D, 3B, and 4B with positive minor effects serve as potential targets for marker assisted breeding to select for improvement of GY and related traits. Following marker validation, these multi-trait loci have the potential to be utilized for MAS to improve GY and adaptation of soft red winter wheat.  相似文献   
10.
This study aimed to identify the potential allelopathic indigenous rice (Oryza sativa L. ssp. indica) varieties from Bangladesh using a performance study in a weed‐infested field and to assess the extent of allelopathic interference relative to resource competition in a glasshouse experiment. Six varieties – namely, “Boterswar,” “Goria,” “Biron” and “Kartiksail” as the most allelopathic, “Hashikolmi” as weakly allelopathic and “Holoi” as nonallelopathic – were raised following a nonweed control method. The infestation levels of weed species were calculated using Simpson's Diversity Index (SDI), which ranged from 0.2 to 0.56. However, a significant correlation coefficient (0.87, P < 0.001) was obtained from these field data compared with the root inhibition percentage from the laboratory bioassay, and the “Boterswar” variety was the most allelopathic. The interactions between the allelopathic variety “Boterswar,” weakly allelopathic variety “Hashikolmi” and Echinochloa oryzicola via a target (rice)‐adjacent (E. oryzicola) cogrowth culture were determined in a hydroponic arrangement. The relative competitive intensity (RCI) and the relative neighbor effect (RNE) values showed that the crop–weed interaction was facilitation for “Boterswar” and competition for “Hashikolmi” and E. oryzicola in rice/E. oryzicola cogrowth cultures. The allelopathic effects of “Boterswar” were much higher than the resource competition in rice/E. oryzicola cogrowth cultures. The converse was observed for “Hashikolmi.” Moreover, the mineral content of E. oryzicola was severely affected by “Boterswar”/E. oryzicola cogrowth cultures’ exudate solution. Therefore, the allelopathic potential of “Boterswar” variety might be useful for developing the weed‐suppressing capacity of rice, which will likely have a significant influence on paddy weed control.  相似文献   
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