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1.
旱地垄沟集雨种植紫花苜蓿最佳沟垄宽比的确定 总被引：3，自引：0，他引：3
采用旱地垄沟集雨种植紫花苜蓿(Medicago sativa L.),研究不同沟垄宽比和覆盖方式对苜蓿干草产量、水分利用效率的影响,并通过回归方程确定适宜我国干旱半干旱区种植紫花苜蓿的最佳沟垄比。结果表明:膜垄、土垄处理平均年干草产量分别为5604.87和4844.81 kg·hm-2,分别较CK提高204.98%和163.63%;膜垄、土垄处理平均水分利用效率分别为34.91和28.47 kg·mm-1·hm-2,分别为CK的2.25倍、1.83倍;膜垄的平均年干草产量、平均水分利用效率分别较土垄提高15.69%和22.62%;回归分析表明:当膜垄的最佳沟垄宽比为60 cm:60 cm、土垄的最佳沟垄宽比为60 cm:70 cm时,苜蓿的经济产量可以达到最大,分别为6009.3 kg·hm-2和5271.5 kg·hm-2,分别较CK提高226.99%和186.84%,膜垄处理的最大经济产量较土垄处理提高14.00%。因此,在试验地区及其相似地区采用膜垄集雨种植能显著提高苜蓿干草产量及水分利用效率,建议采用垄覆膜集雨种植紫花苜蓿,沟垄宽比为60 cm:60 cm。 相似文献
2.
A method based on direct and indirect counting is developed for rapid and accurate linkage analysis for codominant and dominant loci. Methods for estimating gender-specific recombination frequencies are available for cases where at least one of the two loci is multiallelic and for biallelic loci with mixed parental linkage phases where at least one locus is codominant. Most of the estimates of gender-average and gender-specific recombination frequencies required iterative solutions. The new method makes use of the full data set, yields exact estimates of the recombination frequencies when the observed and expected genotypic frequencies are equal, and are computationally efficient. Relative efficiency of various data types is affected by the inheritance mode and by parental linkage phases of biallelic loci, but unaffected by the locus polymorphism when using the full data set for linkage analysis. The ability to determine parental linkage phases is affected by the locus polymorphism as well as inheritance mode. Intercross (or F-2 design) is more efficient for mapping codominant loci, whereas backcross is more efficient if dominance is involved. Mixed parental linkage phases of biallelic loci are less efficient than coupling or repulsion linkage phases. Ignoring noninformative offspring results in biased estimates of recombination frequency for biallelic loci only and reduced LOD scores for all cases. 相似文献
3.
摘要：为获得绿色、有效的断奶仔多系统衰竭综合征防控措施，通过免疫屠宰前60d左右的10头健康育肥猪制备猪圆环病毒2型高免血清，对疑似感染有猪圆环病毒2型的规模猪场母猪及仔猪从预防、紧急治疗两个方面探讨两种生物防控法的防控效果。结果表明，对母猪、断奶仔猪注射制备的猪圆环病毒2型血清抗体制剂并配合敏感抗菌素，其从出生到断奶后30d的存活率及紧急治疗的治愈率均最高，分别达97％和100％；使用猪圆环病毒2型疫苗其次，分别为86％和85％，空白组即仅仅采取加强饲养管理最低，存活率仅为55％。猪圆环病毒2型血清抗体结合使用敏感抗菌素是疑似感染猪圆环病毒2型的规模猪场最有效的生物防控手段。 相似文献
4.
The absolute count for a particular type of blood cell is the total white blood cell count multiplied by the differential percentage for that cell type. Neutrophilia is caused by increased marrow proliferation, redistribution among body neutrophil pools, stress and corticosteroids. Neutropenia is caused by decreased marrow proliferation, ineffective marrow production, reduced neutrophil survival and redistribution of neutrophils. Lymphocytosis is caused by chronic infections and allergic reactions, while lymphopenia is caused by increased lymphocyte destruction, neoplasia and lymphocyte loss. Monocytosis is associated with stress, infections, hematologic disorders, GI disease, necrosis and hemolysis. Eosinophilia is caused by allergic reactions, parasitism, skin diseases, neoplasia and adrenocortical insufficiency. 相似文献
5.
W Everts 《DTW. Deutsche tier?rztliche Wochenschrift》1989,96(3):125-126
Keeping wild animals in captivity is still object of criticism, above all due to the fact that room is restricted for these animals. But wild animal husbandry is basing on several factors: It has to concern physiological requirements as well as natural behaviour patterns, so as actions and reactions of wild living animals caused by ecological occasions have to be replaced by suitable arrangements. Most of the time proper animals husbandry is valued by quantity; in that way, that the measurements of artificial homes are often supposed to be more important than the quality of this enclosures. Optimal feeding, social structure, stimula for behaviour patterns like playing, breeding an rearing in calmness and well trained keepers are other basic requirements for wild animal husbandry. Criteria for keeping wild animals should not be scheduled by restrictive arrangements; innovations would be complicated by any regulations. 相似文献
6.
金科 《四川畜牧兽医学院学报》2006,4(2):201-204
手绘设计草图是电脑设计不可替代的设计表现形式，手绘设计草图的学习是学生提高设计能力的一个关键因素，在现今艺术院校设计专业学生的系统学习中应加强快速手绘草图的训练，并对其技法进行探索和总结。 相似文献
7.
C E Gardner 《Veterinary Clinics of North America: Food Animal Practice》1989,5(3):603-613
Providing quality service to an adequate client base is only part of the challenge of managing a dairy practice. Effective charging for services and efficient collection of charges is necessary for economic survival. Charging by procedure, by time, and by contract are alternatives discussed, as well as methods to manage accounts receivable. 相似文献
8.
Mycobacteriosis is an avian disease that is most commonly caused by Mycobacterium avium or Mycobacterium genavense. In order to optimize molecular laboratory tests for diagnosing mycobacteriosis in birds, we compared four methods of rapid DNA extraction with isolates of M. avium, M. genavense, and Mycobacterium fortuitum. DNA extraction methods included enzymatic lysis, boiling for 30 min followed by enzymatic lysis, four cycles of freezing and thawing followed by enzymatic lysis, and bead beating followed by enzymatic lysis. The DNA yield and purity for the four methods were evaluated by spectrophotometry and compared. The bead beating with enzymatic lysis technique yielded significantly purer and higher concentrations of extracted DNA compared with other DNA extraction methods. All four methods yielded extraction products for all three organisms that were successfully amplified by polymerase chain reaction (PCR) for a fragment in the 65-kD heat shock protein gene. Subjectively, the PCR amplification products were most abundant for samples extracted by bead beating with enzymatic lysis. 相似文献
9.
Lineke Begeman Engbert A. Kooi Erik van Weezep Marco W. G. van de Bildt Chantal B. E. M. Reusken Peter H. C. Lina Marion P. G. Koopmans Judith M. A. van den Brand Thijs Kuiken 《Zoonoses and public health》2020,67(2):198-202
Rabies is caused by infection with a lyssavirus. Bat rabies is of concern for both public health and bat conservation. The current method for lyssavirus prevalence studies in bat populations is by oral swabbing, which is invasive for the bats, dangerous for handlers, time‐consuming and expensive. In many situations, such sampling is not feasible, and hence, our understanding of epidemiology of bat rabies is limited. Faeces are usually easy to collect from bat colonies without disturbing the bats and thus could be a practical and feasible material for lyssavirus prevalence studies. To further explore this idea, we performed virological analysis on faecal pellets and oral swabs of seven serotine bats (Eptesicus serotinus) that were positive for European bat 1 lyssavirus in the brain. We also performed immunohistochemical and virological analyses on digestive tract samples of these bats to determine potential sources of lyssavirus in the faeces. We found that lyssavirus detection by RT‐qPCR was nearly as sensitive in faecal pellets (6/7 bats positive, 86%) as in oral swabs (7/7 bats positive, 100%). The likely source of lyssavirus in the faeces was virus excreted into the oral cavity from the salivary glands (5/6 bats positive by immunohistochemistry and RT‐qPCR) or tongue (3/4 bats positive by immunohistochemistry) and swallowed with saliva. Virus could not be isolated from any of the seven faecal pellets, suggesting the lyssavirus detected in faeces is not infectious. Lyssavirus detection in the majority of faecal pellets of infected bats shows that this novel material should be further explored for lyssavirus prevalence studies in bats. 相似文献
10.
Georgina Limon Elisa G. Lewis Yu-Mei Chang Hugo Ruiz Maria Elba Balanza Javier Guitian 《Preventive veterinary medicine》2014
Livestock disease surveillance is particularly challenging in resource-scarce settings, where disease events are often unreported. Surveillance performance is determined as much by the quantifiable biological attributes of the disease, as it is by motivations and barriers perceived by livestock keepers for disease reporting. Mixed methods designs, which integrate the collection, analysis and interpretation of qualitative and quantitative data in a single study, are increasingly used across different disciplines. These designs allow for a deeper exploration of the topic under investigation, than can be achieved by either approach alone. 相似文献
11.
12.
M Principato 《The Cornell veterinarian》1988,78(1):43-52
Listed and described herein are the main macroscopic lesions produced along the whole digestive tract of free-ranging horses by larvae of the five Gasterophilus spp., occurring in Umbria, a region of central Italy: Gasterophilus intestinalis, Gasterophilus nasalis, Gasterophilus pecorum, Gasterophilus inermis, Gasterophilus haemorrhoidalis. Lesions are classified on the basis of their sizes and shapes and the host's anatomic sites infested, and they are examined in relation to the developmental stages of larvae causing them. The examination of the lesions shows that it is very difficult to differentiate the hemorrhagic impressions caused by migrating 1st and 2nd instar larvae of all the species in the absence of the specific parasite. It is also difficult to differentiate between the gastric lesions caused by Gasterophilus intestinalis and Gasterophilus pecorum. It has been found that an easy identification is possible even in the absence of parasites for gum lesions and for lesions on the soft palate produced respectively by Gasterophilus intestinalis and Gasterophilus pecorum, for duodenal lesions caused by Gasterophilus nasalis, for rectal lesions caused by Gasterophilus inermis and for duodenal and rectal lesions produced by Gasterophilus haemorrhoidalis. 相似文献
13.
F. Preuss 《Anatomia, histologia, embryologia》1987,16(2):153-156
Will and knowledge of animals as topic of evolution-theoretical investigations
Only living beings have a will for action, and all living beings with the exception of man can will nothing else but to survive. The innate will drives them to self-preservation, species-preservation, and self-organization. Only man can renounce to do so. This uniform will is supported by the most differentiated knowledge. In cells this knowledge is chemical and by sensation; in animals it is physical and by sensation. It senses and remedies three bodily needs: hunger, disease, and propagation. Only know-how can remedy needs. The need for knowledge is therefore the primary need, and improvement of knowledge is the decisive evolutionary change.
Chemical knowledge by sensation in most cases is genetic, ground-conscious, and hereditary knowledge. In physical knowledge acquired by sensation, ground-consciousness is lifted to the instinct-conscious level of the nerve cells through which learning-consciousness is developed further. The laws governing this are described elsewhere. 相似文献
Only living beings have a will for action, and all living beings with the exception of man can will nothing else but to survive. The innate will drives them to self-preservation, species-preservation, and self-organization. Only man can renounce to do so. This uniform will is supported by the most differentiated knowledge. In cells this knowledge is chemical and by sensation; in animals it is physical and by sensation. It senses and remedies three bodily needs: hunger, disease, and propagation. Only know-how can remedy needs. The need for knowledge is therefore the primary need, and improvement of knowledge is the decisive evolutionary change.
Chemical knowledge by sensation in most cases is genetic, ground-conscious, and hereditary knowledge. In physical knowledge acquired by sensation, ground-consciousness is lifted to the instinct-conscious level of the nerve cells through which learning-consciousness is developed further. The laws governing this are described elsewhere. 相似文献
14.
Edema disease. 总被引：13，自引：0，他引：13
R A Moxley 《Veterinary Clinics of North America: Food Animal Practice》2000,16(1):175-185
Edema disease is a common cause of illness and death loss in pigs during the first 2 weeks after weaning. The disease is an enterotoxemia caused by strains of E. coli that colonize the small intestine and produce Stx2e. Bacterial colonization is mediated by F18ab fimbriae. Susceptibility to disease is determined by presence of receptors for these fimbriae on small intestinal epithelial cells and is inherited as a dominant trait. Clinical signs and lesions are largely the result of Stx2e, which causes necrosis of endothelial and smooth muscle cells in small arteries and arterioles. Vascular damage in the brain stem with resultant infarction and malacia is the main cause of death in affected pigs. Studies conducted by veterinary researchers in the 1950s and 1960s identified the cause of the disease and provided future scientists with hypotheses to test regarding the pathogenesis. In the last two decades, studies using molecular-based techniques have allowed for the definitive identification of bacterial virulence factors that mediate intestinal colonization and vascular damage, that is, F18ab fimbriae and Stx2e. Identification of these virulence factors has provided a basis for current and future development of effective preventative measures, for example, vaccines. 相似文献
15.
流感病毒作为一种常见的呼吸道病毒,是人类健康和世界经济的巨大威胁。目前流感治疗遇到病毒高度突变的问题,不断完善已有的控制流感感染方法的同时,也需要开阔视野从宿主反应的角度探索控制流感的新措施,本研究从肠道微生物的角度探索流感造成肺损伤的机制。提前3周将组合抗生素和益生元添加到小鼠饮水中构建不同的肠道微生物环境,小鼠感染流感病毒后运用16S rDNA技术测定结肠微生物组成,蛋白免疫印迹法测定肺部Th17和Treg细胞转录因子RORγT和Foxp3的表达情况,苏木精-伊红染色、荧光定量PCR测定肺损伤状况。结果表明,提前使用组合抗生素和益生元能够改变肠道菌群组成,通过降低肠道菌群数目和增加肠道拟杆菌相对丰度保护肠道,从而反作用于肺部诱导肺Treg细胞分化,抑制Th17细胞分化,改善流感造成的肺损伤。 相似文献
16.
17.
IgM-mesangial nephropathy in callithricids 总被引：1，自引：0，他引：1
M Brack 《Veterinary pathology》1988,25(4):270-276
Spontaneous IgM-mediated mesangioproliferative nephropathy was detected in 91% of tamarins and marmosets over 6 months old. The disease remains silent for long periods but is progressive. It is responsible for, or is at least related to, the cause of death in 20% of animals. Morphological characteristics are those of mesangial hyperplasia accompanied by subacute to chronic interstitial inflammation. The immunopathological demonstration of early accumulation of IgM within the mesangial cells and matrix, followed by interstitial deposition of C3, suggests that the lesion is mediated by immunological mechanisms. 相似文献
18.
Dolores Gavier-Widén Michael J Stack Thierry Baron Aru Balachandran Marion Simmons 《Journal of veterinary diagnostic investigation》2005,17(6):509-527
Transmissible spongiform encephalopathies (TSEs) in animals include, among others, bovine spongiform encephalopathy (BSE), scrapie, chronic wasting disease, and atypical forms of prion diseases. Diagnosis of TSEs is based on identification of characteristic lesions or on detection of the abnormal prion proteins in tissues, often by use of their partial proteinase K resistance property. Correctly sampling of target tissues is of utmost importance as this has a considerable effect on test sensitivity. Most of the rapid or screening tests are based on ELISA or Western immunoblot (WB) analysis, and many are officially approved. Confirmatory testing is normally performed by use of histologic examination, immunohistochemical analysis, certain WB protocols, or detection of prion fibrils by use of electron microscopy (scrapie-associated fibril). The discriminatory methods for diagnostic use are mostly based on WB technology and provide initial identification of the prion strain, particularly for differentiation of BSE from scrapie in small ruminants. Definitive prion strain characterization is performed by use of bioassays, usually in mice. A burgeoning number of transgenic mice have been developed for TSE studies. Development of new tests with higher sensitivity and of more reliable diagnostic applications for live animals tested for food safety reasons is a rapidly developing field. Ultimately, the choice of a test for TSE diagnosis depends on the rationale for the testing. 相似文献
19.
The feeding value of fresh pasture grazed in situ is determined by animal performance or productivity and could be relatively easily established for growing and lactating horses. Despite this, there is a lack of published information on the relative feeding value of different pastures and forages grazed by horses in New Zealand and the world. In addition, for adult breeding or non-breeding and young or adult sport or performance horses, the definition of feeding value and its determination remain problematic. Limited information suggests that the feeding value of perennial ryegrass-based pasture in New Zealand for young growing horses is high, and growth rates for Thoroughbred horses fed solely on pasture in New Zealand are similar to those reported from the Northern Hemisphere where grain-based supplements are fed in addition to pasture or other forages. Attempts to assess the ability of fresh pastures to meet the nutrient requirements of horses are hampered by problems associated with determination of feed intake by grazing horses and lack of knowledge of the digestibility and utilisation of digested nutrients, including the relative bioavailability of macro- and micro-minerals in pasture. A further challenge for future research is to determine the effect of herbage allowance and grazing behaviour, including pasture species preferences, on voluntary feed intake by grazing horses. Grazing pasture has benefits for equine health and well-being including reduced risk of some nutrition-related disorders and reduced prevalence of stereotypic behaviour. Pastured horses have greater freedom for expression of natural behaviours including social interaction and exercise. However, grazing pasture is also associated with animal health problems, particularly parasitism and diseases related to pasture-associated toxins. 相似文献
20.
The feeding value of fresh pasture grazed in situ is determined by animal performance or productivity and could be relatively easily established for growing and lactating horses. Despite this, there is a lack of published information on the relative feeding value of different pastures and forages grazed by horses in New Zealand and the world. In addition, for adult breeding or non-breeding and young or adult sport or performance horses, the definition of feeding value and its determination remain problematic. Limited information suggests that the feeding value of perennial ryegrass-based pasture in New Zealand for young growing horses is high, and growth rates for Thoroughbred horses fed solely on pasture in New Zealand are similar to those reported from the Northern Hemisphere where grain-based supplements are fed in addition to pasture or other forages. Attempts to assess the ability of fresh pastures to meet the nutrient requirements of horses are hampered by problems associated with determination of feed intake by grazing horses and lack of knowledge of the digestibility and utilisation of digested nutrients, including the relative bio availability of macro- and micro-minerals in pasture. A further challenge for future research is to determine the effect of herbage allowance and grazing behaviour, including pasture species preferences, on voluntary feed intake by grazing horses. Grazing pasture has benefits for equine health and well-being including reduced risk of some nutrition-related disorders and reduced prevalence of stereotypic behaviour. Pastured horses have greater freedom for expression of natural behaviours including social interaction and exercise. However, grazing pasture is also associated with animal health problems, particularly parasitism and diseases related to pasture-associated toxins. 相似文献