温度对异色瓢虫实验种群的影响

为探索饲养异色瓢虫的最适温度,了解其对高温的耐受性,在15、20、25、30和35℃恒温条件下,研究温度对异色瓢虫发育、存活和繁殖的影响。结果表明,在15～25℃时,异色瓢虫各虫态发育历期随温度的升高而缩短,25℃和30℃时世代历期最短,分别为23.0天和22.4天;世代发育起点温度和有效积温分别为8.54℃和432.61日.度。在20～30℃时,雌性成虫的寿命随温度的升高而缩短,且雌雄个体间无明显差异;25℃时单雌产卵量最高、产卵历期最长,为2193.0粒和63.6天,但产卵历期与20℃时无显著差异。在25℃下,异色瓢虫的种群趋势指数和内禀增长力均较高,分别为916.7和0.12,表明25℃是异色瓢虫生长、繁殖的最适温度。     

微生物发酵中药的研究现状及其在养殖业中的应用

发酵法是中药炮制的传统方法,具有提高有效成分含量、增强或产生新的疗效、降低毒性、调整肠道菌群等作用。现代中药发酵技术克服了传统中药发酵技术的菌种驳杂、温度和湿度不可控等缺点,发展出了固体发酵、液体发酵和双向固体发酵的现代工艺技术。近年来国家推行饲料禁抗,微生物发酵中药作为一种微生态制剂,在提高动物生产性能、提高动物机体免疫力、预防和治疗疾病等方面,以其独特的优势成为养殖业中抗生素替代品之一,在畜禽养殖业和水产养殖业有着巨大的潜力和市场。但目前发酵中药仍存在发酵机理不明确、物质基础的改变相对未知、发酵菌种较为单一、缺少一定的质量标准等问题。作者重点介绍了发酵中药的优势并比较了各种发酵技术的优点和缺点,对发酵中药在畜禽养殖和水产养殖中的应用进行了归纳总结,分析了发酵中药的发展潜力以及目前存在的问题、改进方案及发展方向,以期对未来微生物发酵中药的深入研究及其在畜禽、水产养殖业中的应用提供思路与借鉴。     

Characteristics and dynamics analysis of Populus euphratica populations in the middle reaches of Tarim River

Populus euphratica Oliv. is widely distributed along the Tarim River. Maintaining stability of P. euphratica population is important to local development. This study explored the static life table, survivorship curves and four function curves (survival rate, cumulative mortality rate, mortality density, and hazard rate), and development index of P. euphratica population in the middle reaches of Tarim River. The results indicated that the age structure of P. euphratica population belonged to positive pyramidal type, which meant young age-class individuals occupied most populations. The number ofⅠ-Ⅱage classes accounted for 66.2% of whole population, and this indicated that there were abundant subsequent seedlings resources to support the growth of P. euphratica population in the middle reaches of Tarim River. The survivorship curve of P. euphratica belonged to the Deevey Ⅲ (concave-type) and the development index was 47.72%. Four function curves revealed that the individuals of P. euphratica sharply decreased at the initial stage and then leveled off at the late stage of survival curve. Time sequence prediction models predicted that the number of midlife individuals would increase in future 10, 20, 30 years, and P. euphratica population grew steadily as a result of rich saplings.     

准噶尔盆地东南缘天然更新梭梭苗期动态生命表及生存分析

运用动态生命表方法,观察和分析了准噶尔盆地东南缘天然梭梭(Haloxylon ammodendron)幼苗生长动态。结果显示:梭梭当年生幼苗存在两个存活率下降快、死亡率和致死力高的阶段。第一阶段从4月1日至5月1日幼苗死亡率为69.9%。第二阶段为6月15日至7月15日,幼苗死亡率由79.1%增加到85.1%。早期生长阶段的高死亡率,是由于动物咬食和不利气候因素的影响;而后一阶段死亡率较高的原因,是由于浅层土壤水分下降所致。存活曲线属DeeveyⅢ型,表明幼苗早期个体死亡率较高,此阶段是幼苗天然更新的关键时期。幼苗期动态生命表的研究可以为梭梭天然更新及其管理措施的制定提供科学依据。     

塔里木河干流中游胡杨种群特征与动态分析

通过样地调查和数据统计,编制胡杨种群静态生命表,绘制存活曲线、生存率曲线、累计死亡率曲线、种群死亡密度曲线和危险率曲线,分析种群数量特征。同时,结合种群动态量化方法及时间序列预测,分析种群数量动态变化。结果表明:胡杨种群年龄结构呈金字塔型,幼龄级所占比例较大;存活曲线接近Deevey C(凹)型,且动态指数大于0,表明胡杨种群结构合理,为增长型种群。4个函数曲线表明,胡杨种群前期幅度变化较大,后期趋于稳定。时间序列分析表明,由于丰富的后续资源,种群能够稳定生长。     

Hypernatremia secondary to homemade play dough ingestion in dogs: a review of 14 cases from 1998 to 2001

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.     

Near‐surface macropore flow and saturated hydraulic conductivity in drained and restored blanket peatlands

The impacts of blanket peatland management on water tables, near‐surface macropore flow and saturated hydraulic conductivity were investigated using automated dipwells and mini‐disc tension infiltrometers. Three neighbouring hillslopes which were undisturbed, drained and restored by drain blocking were studied. Mean water table depths at the undisturbed sites were slightly shallower than at the restored site and water tables at both sites were significantly shallower relative to the drained treatment. Through time, however, the water table at the restored treatment behaved in a markedly different way to that at the undisturbed site. Water tables reached the peat surface for only 2% of the time for the drained and restored treatments compared to 18% for the undisturbed treatment. The proportion of runoff flowing through macropores in the near‐surface layers of the peat was found to be large (≥60%) across all three treatments, yet functional macroporosity was found to be significantly greater in the undisturbed peat relative to the two other treatments. Meanwhile, saturated hydraulic conductivity was found to be significantly higher at the restored treatment relative to the two other treatments, with mean conductivities ca. 1.5 times greater, suggesting a form of heightened soil–water interaction. Combined, the results indicate that although restoration by ditch blocking may result in a relatively successful water table recovery, there may not be the full reinstatement of peatland hydrological processes.     

中草药饲料添加剂改善禽肉品质的研究

通过对近年来相关文献的整理分析，归纳总结了一些中草药对禽肉品质产生的影响及其实现途径，为开发味美且绿色安全的优质禽肉产品提供思路。     

香菇多糖的免疫调节作用及在家禽上的应用

香菇多糖是从香菇中提取分离的一种活性多糖,具有较强的免疫活性作用。本文综述了香菇多糖的免疫调节作用及其在家禽中的应用效果。