科尔沁沙地灌溉与施肥对退化草地生产力的影响

在科尔沁沙地典型退化草地上开展了裂区组合设计的灌溉与施肥二因素试验。结果表明,科尔沁沙地退化草地土壤储水量受降水量的影响强烈。由于受到干旱气候和灌溉量的影响,灌水仅对地表0~30 cm的土壤含水量变化有作用,对深层土壤的含水量没有作用。灌溉和施肥对沙地退化草地的植物生物量有着明显的促进作用。灌溉处理中,灌溉90 mm试验区的植被生物量为最高(128.3 g/m2),施肥处理中,每hm2施600 kg氮肥试验区的植被生物量为最高(147.3 g/m2)。灌溉90,60,30 mm和对照试验区的植被耗水量分别为379.00,349.90,313.20和293.50 mm。与其相应的水分利用率分别为0.28,0.38,0.34和0.35 kg/(mm.hm2)。综合分析认为科尔沁沙地退化草地的基本耗水量为294 mm。     

苗期紫花苜蓿品种抗旱性初步研究

运用多元统计分析方法,以来自、美国、澳大利亚、加拿大及中国的22个紫花苜蓿Medicago sativa品种（种群）为试验材料,对紫花苜蓿在苗期进行短期干旱胁迫,依据试验测定的15个形态指标和生理指标,应用主成分分析、聚类分析法,对22个紫花苜蓿品种试验材料的抗旱能力进行综合评价。通过运用主成分分析法将15项相关的抗旱性指标简化为5个独立且功能明确的主成分,并以5个主成分的得分系数运用聚类分析法把22份材料聚为三大类,从而将22份材料分为强抗旱性品种、中抗旱性品种、弱抗旱性品种,为下一步抗旱机制的研究提供参考。     

Describing the growth and molt of modern domestic turkey (Meleagris gallopavo) primary wing feathers

The use of feathers as noninvasive physiological measurements of biomarkers in poultry research is expanding. Feather molting patterns and growth rates, however, are not well described in domestic poultry. These parameters could influence the measurement of these biomarkers. Therefore, the objective of this study was to describe the juvenile primary feather molting patterns and feather growth rates for domestic turkeys. The 10 primary wing feathers of 48 female turkeys were measured weekly from week 1 (0 d of age) to week 20. Feathers were manually measured, and the presence or absence of each primary feather was recorded weekly. Generalized linear mixed models were used to investigate if feather growth differed between the primary feathers. The molting of the juvenile primary feathers followed a typical descending pattern starting with P1 (5 wk of age), while P9 and P10 had not molted by the end of the study (20 wk of age). The average feather growth rate was 2.4 cm/wk, although there was a significant difference between the 10 primary feathers (P < 0.0001, 2.1 to 2.8 cm/wk). Over time, feather growth followed a pattern where the growth rate reaches a peak and then declines until the feather is molted. The results of this study provide a critical update of patterns of molting and feather growth in primary wing feathers of modern turkeys. This can have implications for the interpretation of physiological biomarkers, such as the longitudinal deposition of corticosterone, in the feathers of domestic turkeys.     

鄂尔多斯油蒿-本氏针茅群落生物量

在5年逐月观测基础上，利用多元分析方法，建立鄂尔多斯高原沙地油蒿－－本氏针茅群落地上生物量对气候因子影响的逐月回归模型，结果表明，气候因子在不同时期对植物生长的作用差异显著，降水因子在各月都是影响生物量的显著因子，二者呈正相关，日照时数仅在6月对生物量产生显著影响，。平均气温在各月都不对生物量产生显著影响，7－10月各月生物量都受前月生物量的显著影响，说明植物生长的持续性对生物量的形成和积累是重要的，应用本文建立的模型对3种不同气候条件下，各月生物量的波动范围进行预测，建立累积回归模型，将逐月回归模型，累积回归模型的模拟值与实测值进行比较，结果在多数年份，逐月回归模型都比累积回归模型更接近实测值，与传统的累积回归模型相比，本模型具有三方面的优越性，即可揭示气候影响植物生长的重要细节，具有预测能力以及精度更高，因此是对传统累积气候模型进行的有益改进。     

Improvement of small dairy producers in the central coast of Peru

The objective of this study was to characterize a group of small dairy producers in the central coast of Peru and determine the most important limiting factors that affect animal productivity, using Participatory Rural Appraisal methodologies. The information collected during a year included biological and socio-economic characteristics. Inappropriate nutrition, management, health and reproduction were observed in most farms. The average number of animals per family was 17.3, of which 40% were bulls and growing calves. Milk production and net cash income were reduced in the summer. The feeding programme for lactating and growing females of forage exchanged for labour and purchased concentrates did not theoretically or practically meet the cows’ needs. All water was carried to the site on donkeys from one kilometre distance. All cows were negative for a number of potential infectious diseases. By California Mastitis Test of routine samples 7.1% of cows had clinical mastitis and 66.1% subclinical. Taking notional labour and forage costs into account, milk production was at a loss but the farmers considered neither and were satisfied with a net cash income from milk sales three times the average agricultural wage.     

河南省陆地植被净第一性生产力估算及其时空分布

基于地理信息系统和卫星遥感技术,利用地面气象数据和MODIS数据,同时考虑河南省自身实际地理和植被覆盖情况,在对最大光利用率和水分胁迫系数的获取进行改进的基础上,利用CASA模型对河南省植被净第一性生产力（NPP）进行了估算,并分析了其时空分布。结果表明,2008年河南省NPP生产量为34.87 Mt C,NPP空间分布和植被类型有密切关系,森林植被最大,然后依次是灌丛、草地、农田等。12、1和2月NPP最小,植物基本停止生长,植被的NPP只占全年的1.38％;5、7和8月的NPP最大,占全年总量的56.84％。与Miami、Montreal、Chinkugo模型相比,本研究结果和Miami模型结果最为接近,植被类型NPP均值排序和Chinkugo模型相似;与实测数据对比结果显示,模拟值接近于实测值,说明模型适用于河南省NPP的模拟。     

现代商品仔猪传代肾细胞株的培育与应用研究

细胞系是动物病毒分离培养的重要载体。本研究以现代商品化仔猪肾脏为原始材料,拟培育新的细胞系用于动物病毒的分离和培养。利用胰酶消化法和差速贴壁相结合方法,分离纯化仔猪肾上皮细胞,并在体外进行传代培养和筛选。结果显示,试验成功得到一株可以连续传代的细胞株,命名为SDPK-D,且已在体外连续传代90代。SDPK-D细胞株F33和F83代倍增时间分别为40.9和32.7 h,细胞活率分别为97.55%和98.86%,8 h细胞贴壁率分别为91.67%和97.06%。在该细胞株接种猪伪狂犬病病毒（PRV）、猪流感病毒（SIV）、猪流行性腹泻病毒（PEDV）阳性病料均出现明显的细胞病变。本研究首次针对现代商品猪培育出一株可以在体外连续传代的细胞株,并对多种动物病毒敏感,为相关动物病毒的分离培养提供了新的细胞系选择。     

高寒牧区栽培毛苕子多次刈割生产性能研究

对毛苕子不同刈割时间与次数的生产性能进行了对对比,发现其生产能力有很大差别,试验证明,在高寒牧区栽培毛苕子,在整个生育期内刈割２次可获得最高产草量,一茬草与二葜最佳刈割期分别为初花期和结荚初期。     

几种鸡胚原代细胞的制备方法

在病毒分离、繁殖，中和试验及药物毒理试验中，细胞培养是经常被选用的技术。本文描述通过选择不同日龄的鸡胚，分别对皮肤上皮细胞、肝细胞和肾细胞进行了组织培养，确定了生长所需的培养液要求。认为１２日龄鸡胚适于皮肤上皮细胞的制备，１７～２０日龄鸡胚适合于肝细胞、肾细胞的制备，并确定了细胞生长的ｐＨ条件。     

脂肪细胞培养研究现状

脂肪细胞培养为研究脂肪代谢紊乱疾病提供了一种有效的途径。基质血管成分系统的研究形成了完整的前脂肪细胞理论,随后脂肪细胞原代培养技术得到了广泛的研究,国外各种家畜的脂肪细胞培养模型得以建立,而国内在脂肪细胞培养方面的研究起步较晚,且多集中于人及鼠的脂肪细胞培养。脂肪细胞的传代培养在单一因子对脂肪细胞的功能研究上有一定的优越性,尤其对不宜于在活体采样的人及动物。脂肪细胞培养的另一个研究方向是脂肪细胞与其他组织细胞的联合培养,对研究机体内各种组织细胞间的相互作用提供了良好的基础。