首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   17篇
  免费   0篇
林业   2篇
  1篇
农作物   2篇
水产渔业   1篇
畜牧兽医   11篇
  2021年   1篇
  2020年   1篇
  2016年   1篇
  2012年   2篇
  2011年   2篇
  2010年   1篇
  2009年   2篇
  2008年   1篇
  2007年   2篇
  2006年   1篇
  2005年   1篇
  2004年   1篇
  1980年   1篇
排序方式: 共有17条查询结果,搜索用时 15 毫秒
11.
The objectives of this study were to examine the effects of beak trimming age on performance criteria, H-L ratio, antibody production, the percentage of spleen and liver and external appearance. The chicks (Barred Rock) were randomly divided into 4 beak-trimming groups (non-trimmed (control), a trim at 1 d (1D), at 10 d (10D) and at 10 wk (10W)), each of 132 chicks. There were 6 replicate cages at beak trimming groups at rearing period. At 18 wk of age a total of 144 pullets were transferred to the layer house, and the pullets were housed at 323 and 646 cm2/hen with 8 and 4 birds per cage in three-deck layer cages. There were a total of 24 replications with 12 replications equally divided between the high and low density cages, and the beak trimmed treatments were randomly and equally divided within each density. As a result of this experiment differences among groups in body weight in rearing phase were disappear in the laying phase. Low feather condition was found in untrimmed hens. H-L ratio in both pullet and laying phase was higher in hens of untrimmed groups. Cage area affected all examined parameters except that body weight, mortality rate, cracked, broken and unshell egg rates, shell breaking, shape index, shell thickness, meat-blood spot rates, spleen and liver percentages, throat injures and antibody production to SRBC.  相似文献   
12.
13.
This study was designed to investigate the effect of feeding on the plasma disposition of triclabendazole (TCBZ) in goats following oral administration. A total of eight goats, aged 14–16 months and weighing 20–30 kg were used in this study. The animals were allocated into two groups (fasted and fed groups) of four animals each. The goats in fed group were fed ad libitum but the animals in fasted group were not fed 24 h before and 6 h after drug administration. Commercial oral drench formulation of TCBZ (Endex-K, 5%) was administered orally to animals in two groups at dose of 10 mg/kg bodyweight. Heparinized blood samples were collected between 1 and 192 h after treatment and the plasma samples were analysed by high performance liquid chromatography (HPLC) for TCBZ, TCBZ sulphoxide (TCBZ–SO), and TCBZ sulphone (TCBZ–SO2). Relatively very low concentration of TCBZ parent drug was detected between 2 and 48 h, but TCBZ–SO and TCBZ–SO2 metabolites were present between 2 and 192 h in the plasma samples of fed and fasted animals. Fasting significantly enhanced the plasma concentration of TCBZ and its metabolites. The availability of TCBZ, TCBZ–SO and TCBZ–SO2 in the plasma samples of fasted goats were markedly greater compared to those of fed goats. It was concluded that fasting decreases the digesta flow rate and prolongs the retention of the drug into the gastrointestinal tract, resulting in enhanced quantitative gastrointestinal absorption or systemic availability of TCBZ and its metabolites in fasted goats.  相似文献   
14.
In the present study, fish meal (FM) was replaced by pea (Pisum sativum) protein (PP) in diet for Rainbow trout (Oncorhynchus mykiss) at levels of 0% (PP0), 25% (PP25), 50% (PP50), 75% (PP75) and 100% (PP100), and the effect of dietary PP level on the digestive system tracts and liver was investigated by micromorphological and histopathological evaluations. Morphometric measurements (mm 100g fish−1) of the liver width and stomach length in rainbow trout were found to be significantly larger (p <0.05) in fish with high-level pea protein as the main protein source (PP75, PP100) compared to the low-level PP replacement group (PP25). No significant differences were found in morphometric measurements for pyloric caecum and intestines among treatment groups, whereas the number of the caecum of fish fed the PP25 diets significantly increased over the control (PP0) (p<0.05). In the histological examination of the liver, mild hydropic and vacuolar degeneration was observed in all experimental groups except PP0 and PP25. The measurements of pyloric caecum fold height, enterocyte length and width of tunica muscularis of the high-level pea protein groups of PP75 and PP100 were significantly higher (p <0.05) compared to the control group. In conclusion, 25% substitution of PP can be suggested for FM in trout diets, because the findings of the present study provided evidence that the digestive system improved by increasing the number of pyloric caecum at this replacement level.  相似文献   
15.
Objective: To describe a lingual arch bar technique for fixation of rostral mandibular body fractures and report outcome in 16 cats. Study Design: Original study. Animals: Cats (n=16) with rostral mandibular body fracture (10 bilateral, 6 unilateral) just caudal to the canine teeth. Methods: Orthodontic wire (Dentaurum®; 0.9 mm) was used as a lingual arch bar by contouring it to the shape of the lingual side of the alveolar margin, and secured by circum‐mandibular wires passed interproximal to teeth. Stability of fixation, occlusion, tolerance to the lingual arch bar, degree of secondary gingivitis/periodontitis, and ability to eat were evaluated clinically, and fracture union was assessed radiographically. Results: The lingual arch bar was well tolerated. Eleven cats without a feeding tube were able to eat within 24 hours. Time to fracture union and appliance removal ranged from 28 to 64 days (mean, 42.5 days). Malocclusion of the rostral part of the fracture occurred in 5 cats; however only 1 required correction. Conclusions: Intraoral stabilization of rostral mandibular fractures using a lingual arch bar is a simple and effective method for the treatment of rostral mandibular fractures just caudal to the canine teeth.  相似文献   
16.
This study was conducted to assess the role of increasing N supply in enrichment of whole grain and grain fractions, particularly the endosperm, with Zn and Fe in wheat. The endosperm is the most widely consumed part of wheat grain in many countries. Plants were grown in the greenhouse with different soil applications of N and Zn and with or without foliar Zn spray. Whole grain and grain fractions were analyzed for N, P, Zn and Fe. Increased N supply significantly enhanced the Zn and Fe concentrations in all grain fractions. In the case of high Zn supply, increasing N application enhanced the whole grain Zn concentration by up to 50% and the endosperm Zn by over 80%. Depending on foliar Zn supply, high N elevated the endosperm Fe concentration up to 100%. High N also generally decreased the P/Zn and P/Fe molar ratios in whole grain and endosperm. The results demonstrate that improved N nutrition, especially when combined with foliar Zn treatment, is effective in increasing Zn and Fe of the whole grain and particularly the endosperm fraction, at least in the greenhouse, and might be a promising strategy for tackling micronutrient deficiencies in countries where white flour is extensively consumed.  相似文献   
17.
The chemical diversity of antioxidants makes it difficult to separate and quantify antioxidants from the vegetable matrix. Therefore, it is desirable to establish a method that can measure the total antioxidant activity level directly from vegetable extracts. The current literature clearly states that there is no "total antioxidant" as a nutritional index available for food labeling because of the lack of standard quantitation methods. Thus, this work reports the development of a simple, widely applicable antioxidant capacity index for dietary polyphenols and vitamins C and E, utilizing the copper(II)-neocuproine [Cu(II)-Nc] reagent as the chromogenic oxidizing agent. Because the copper(II) (or cupric) ion reducing ability of polyphenols is measured, the method is named by our research group "cupric reducing antioxidant capacity" abbreviated as the CUPRAC method. This method should be advantageous over the ferric reducing antioxidant power (FRAP) method because the redox chemistry of copper(II)-as opposed to that of ferric ion-involves faster kinetics. The method comprises mixing of the antioxidant solution (directly or after acid hydrolysis) with a copper(II) chloride solution, a neocuproine alcoholic solution, and an ammonium acetate aqueous buffer at pH 7 and subsequent measurement of the developed absorbance at 450 nm after 30 min. Because the color development is fast for compounds such as ascorbic acid, gallic acid, and quercetin but slow for naringin and naringenin, the latter compounds were assayed after incubation at 50 degrees C on a water bath for 20 min [after Cu(II)-Nc reagent addition] so as to force the oxidation reaction to reach completion. The flavonoid glycosides were hydrolyzed to their corresponding aglycons by refluxing in 1.2 M HCl-containing 50% MeOH so as to exert maximal reducing power toward Cu(II)-Nc. Certain compounds also needed incubation after acid hydrolysis to fully exhibit their reducing capability. The CUPRAC antioxidant capacities of synthetic mixtures of antioxidants were experimentally measured as Trolox equivalents and compared to those theoretically found by making use of the principle of additivity of absorbances assuming no chemical interaction between the mixture constituents. Because ascorbic acid is not resistant to elevated temperature incubation, it should be assayed initially by measuring the absorbance (at 450 nm) difference of original and ascorbate oxidase-added mixture solutions at the end of 1 min of Cu(II)-Nc reagent addition. Thus, the total CUPRAC antioxidant capacity of a mixture containing various antioxidants should be that finally measured after a suitable combination of hydrolysis and incubation procedures, added to the initially measured capacity due to ascorbate. The antioxidant polyphenolic compounds tested demonstrate that the highest capacities in the CUPRAC method were observed for epicatechin gallate, epigallocatechin gallate, quercetin, fisetin, epigallocatechin, catechin, and caffeic acid in this order, in accordance with theoretical expectations, because the number and position of the hydroxyl groups as well as the degree of conjugation of the whole molecule are important. The antioxidant potency of flavonoids is nearly proportional to the total number of -OH groups and is positively affected by the presence of an o-dihydroxy moiety in the B-ring. beta-Carotene, which did not react with the CUPRAC reagent in alcoholic aqueous medium, could be assayed in dichloromethane solvent. Linear calibration curves for ascorbic acid and flavonoids were redrawn in synthetic solutions containing a mixture of antioxidants, and also in real matrices such as grape and orange juices, green tea, and blackberry tea, showing an initial nonzero absorbance with the CUPRAC reagent. The parallellism of the linear calibration curves of pure compounds in a given complex matrix effectively demonstrated that there were no interferent chemical interactions among the solution constituents and that the antioxidant capacities of the tested antioxidants were additive. The CUPRAC reagent is reasonably selective, stable, easily accessible, and sensitive toward thiol-type oxidants, unlike the FRAP method. The reaction is carried out at nearly physiological pH as opposed to the unrealistic acidic pH of FRAP.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号