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Tropical Animal Health and Production - In Algeria, the epidemiology of cattle abortions is not well understood. Therefore, the present study aims to estimate the prevalence of abortion in 75...  相似文献   
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Camel fertility faces many problems, which could be solved by assisted reproductive technologies (ARTs). We designed the experiment to explore the effect of different cryoprotectant concentrations and combinations on viability and maturation rates of vitrified/warmed camel oocytes. We collected ovaries directly after slaughtering from local abattoir and transported them to laboratory in a thermo‐flask containing normal physiological saline. We aspirated the oocytes from follicles, which is 2–8 mm in diameter, washed three times in TCM‐199 and then examined under stereo‐microscope for selection. We selected morphologically normal oocytes with an evenly granulated cytoplasm and a compact cumulus cell layer. We equilibrated morphologically normal oocytes in equilibration solution (ES), which is half concentration of vitrification one. After equilibration, We transported oocytes to vitrification solution using ethylene glycol (EG, 40%), dimethyl sulphoxide (DMSO, 40%) and EG 40% + DMSO 40%. The obtained results revealed that addition of EG 40% + DMSO 40% resulted in the best quality of vitrified/warmed oocytes, which is demonstrated by higher per cent survival rate (90.16%) and maturation rate (58.95%). While DMSO 40% resulted in 62.79% and 29.54%, respectively, EG 40% reported 86.11% and 53.47%, respectively. We could conclude that vitrification of immature camel oocytes by using 40% EG + 40% DMSO is suitable methods to limit drawbacks of vitrification methods, and we need further studies to assess the ability of in vitro‐produced blastocyst to develop in vivo and establish pregnancy after embryo transfer.  相似文献   
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Astroglial account for the largest glial population in the brain and play a variety of vital functions in the development of the central nervous system (CNS). An immunohistochemical study was performed in 19 ovine foetuses ranging from 2 to 5 months of gestation, one newborn lamb and three adult sheep. Using the anit-glial fibrillary acidic protein (GFAP) marker, several variations were found in the degree of GFAP positive (GFAP+) astrocyte distribution between the different zones in the cerebellum of sheep during brain development. Our study indicates that the first appearance of astrocytes from restricted zones in the cerebellum occurs around the eighth week of gestation. Bergmann cells were found to be present from around the 15th week of gestation onwards. Our findings suggest that the maturation of astrocytes begins in the caudal parts of the cerebellum, developing from their initial ventral regions to spread first to dorsal regions radially within the white matter, then followed by the more rostral parts of the cerebellum. Astrocytes were also found to proliferate in the vermis before appearing in the cerebellar hemispheres.  相似文献   
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The larvicidal activity of sustained-release formulations ofBacillus thuringiensis H-14 (Bactimos briquets) and controlledrelease plastic formulations of Abate against mosquito larvae ofAedes aegypti (L.) has been evaluated. The test formulations provided continuous effective control with 90–100% larval mortality for several weeks. The presence of suspended soil constituents was associated with a lowering of larval mortality and tended to reduce the durations of effective control of Bactimos and Abate plastic pellets against mosquito larvae by about 1.8 and 2.2 times, respectively. Treatments with such formulations did not appear to prevent hatch of eggs which oviposited after application, but all newly hatched larvae failed to develop beyond the second instar.  相似文献   
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Objective To investigate wool organophosphorus concentrations resulting from a range of farm pesticide application methods.
Design Random sampling of wool for pesticide residues and on-farm interviews to determine associated treatments.
Procedure Tasmanian fleece wool lots were sampled at random and tested for organophosphorus residues. The grower was identified and the pesticide treatments applied to the sheep were ascertained by on-farm interview.
Results The residue concentrations showed a large variation that was not accounted for by differences in treatments by growers. Organophosphorus concentrations were proportional to the number of treatments applied, and inversely related to the time between pesticide application and the subsequent shearing, and were significantly influenced by the method of application. After allowing for the time of application, plunge dipping resulted in pesticide residue concentrations 2 to 2.5 times greater than shower dipping, using spray races or hand jetting, and the use of these methods caused larger residues than the use of jetting races.
Conclusions We recommend that plunge or shower dipping should not be used more than 7 weeks after shearing, nor at higher concentration than the standard dose rate used for lice control, whereas jetting may be satisfactory for up to 7 months after shearing, provided only one application is administered.  相似文献   
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The Government of Egypt is mandated toplan, construct, operate, manage, andmaintain the water system. However, withthe growing water demands over supplies inthe country, water management became a verydifficult task. This has led Egypt toreform policies, technologies,institutions, and development strategies tomanage water more effectively. One of thesestrategies is the irrigation managementtransfer (IMT) that has been a majorstrategy adopted to encourage farmers toplay a more important role in irrigationmanagement and related water services andalso share the cost of O&M of irrigationand drainage systems. IMT policy islaunched in Egypt as a pilot phase toexpand water users' participation atsecondary levels of the irrigation anddrainage systems. Four pilot areas (5,000–8,000 acre) representing all categories andgeographical locations of agriculturallands of Egypt were selected to implementthis policy.This study was conducted in these pilotareas prior to the start of any IMTactivities to describe, analyze, andexplain farmers' attitudes towardirrigation maintenance and implementationof IMT process. Socio-economicquestionnaires were designed and used asthe main tool for data collection. Afterthe field pre-test of the surveyinstrument, a sample of 240 farmers, 60from each pilot area, was selected usingthe sampling frame of multi-tiered process,and the statistical data analysis was doneusing SpssWin software.The major result of this study is that,without proper education and interface withfarmers, there is widespread resistance tothe idea farmers assuming management andmaintenance responsibilities beyond theon-farm level. It would have to proceedvery cautiously, and yield responsiveresults if it were to survive in the faceof the attitudes the farmers have shown,with their strong belief in the necessityof the role of the government. Meanwhile,farmers expressed great confidence in theIMT process and its objectives.  相似文献   
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