土壤施用喹硫磷防治桑瘿蚊试验

经三年防治桑瘿蚊农药筛选试验和家蚕残毒测定结果表明,5%喹硫磷粉剂是取代有机氯农药防治桑瘿蚊的有效土壤处理剂.得出:(1)5%喹硫磷粉剂对防治桑瘿蚊有良好的效果.1983年小区试验校正防效为95.7%,1984年和1985年大田试验为89.14—91.56%,与有机氯农药相似.(2)施用安全,采用施药区内桑叶养蚕均无急性中毒现象发生.(3)越冬代桑瘿蚊的生活力,休眠体最强,蛹最弱,在5月中旬对越冬代桑瘿蚊的蛹期施药效果最好.但是,喹硫磷对桑瘿蚊的各个发育阶段都有良好的毒杀作用.     

营养学中氨基酸平衡的度量

本文基于聚类分析理论,提出了失衡度(IBD)这一新的化学指数,借以定量地研究蛋白质营养中的氨基酸平衡问题。当样品中氨基酸完全平衡时,IBD取值为零;而当其氨基酸平衡最差时。IBD取值为1。IBD的氨基酸增量模型为非对称最大值式;且IBD与变异系数(CV)之间有着密切的关系。通过IBD这一指数,可以对各种单一饲料的蛋白质营养价值加以分类列等;通过计算两种以上饲料蛋白质混合物的IBD,可以从理论上预测它们之间是否互补,以及何时发生最佳互补关系。若引申IBD的概念框架,还可以用来研究其它养分之间的平衡关系,并有助于实现计算机配方过程的自动鉴别和筛选。     

Appraisal of the sustainability of dairy goat systems in Southern Spain according to their degree of intensification

This investigation aims to classify, describe and evaluate the sustainability of dairy goat production systems (GPS) in South Spain Sierra de Cadiz. The research took place throughout 25 goat farms during the 2001–2002 campaigns, with the method posed by Masera et al. (1999) [Masera, O., Astier, M., S., López-Ridaura. 1999. Sustentabilidad y manejo de recursos naturales. El marco de evaluación MESMIS (Sustainability and natural resource management. The MESMIS evaluation framework). Mundi-Prensa, S.A., Gira, IE-UNAM, México. 109 pp.] and adapted to animal production systems, as the guideline and framework to evaluate sustainability.

The principal component, namely energy input from grazing (eigenvalue 1.329) which comprises the indicators total area per goat (factorial value 0.664) together with net energy obtained from grazing (factorial value 0.903) allowed to differentiate significantly between semi extensive (SES), semi intensive (SIS) and intensive (IS) goat production systems.

Intensification of the GPS tends to be inefficient, especially in terms of net margin per litre of milk produced (p < 0.05). A higher degree of adaptability of IS (64.8%) derives from a higher investment on new production strategies. Likewise, higher self-management capacity of SES (60.9%) fosters standards of productivity (76.0%) and stability (42.9%). The SIS presented the highest equity values (67.8%).

On the whole, sustainability of GPS tends to decrease as the degree of intensification increases: SES = 57.3%; SIS = 55.7% and IS = 53.1%. The reduction of the dependency on external input alongside with the optimization of natural resources management would surely improve the standard of sustainability.     

不同放牧方式对山地草甸生产与生态功能及其权衡关系的影响

为实现喀纳斯景区山地草甸的可持续管理,本研究通过设置无牧对照(NG)、单牧马-轻牧区(HG)、牛马混牧-重牧区(MG)三种放牧方式,探求提高山地草甸生态系统多项生产和生态功能协同性的放牧方式。结果表明：不同放牧方式下山地草甸的生产功能放牧后较放牧前均有下降,生态功能中土壤N:P、植物N:P、凋落物N:P放牧后较放牧前均升高,其他生态功能降低,但HG的Shannon-Wiener指数在放牧后变化不大;NG的土壤呼吸速率和植被C:N升高。在山地草甸生态系统生产和生态功能的权衡关系中,权衡、协同和不相关关系同时存在,与牧草产量,草地质量指数相关的生产和生态功能存在协同关系;与植被平均高度、土壤呼吸速率、土壤碳储量相关的生产和生态功能存在权衡关系,其余指标为不相关关系。综上所述,最适放牧方式为HG,其协同关系最佳。     

湟源县奶牛冷配技术推广情况调查与分析

对近年来青海省湟源县牛冷配技术推广情况进行了调查和分析,认为湟源县牛冷配技术推广效果良好．但仍存在问题,并提出了解决问题的措施。     

中国荷斯坦种公牛BLAD遗传缺陷的分子检测及系谱分析

本试验运用限制性片段长度多态性聚合酶链式反应（RFLP-PCR）方法,检测我国荷斯坦种公牛白细胞粘附缺陷（bovine leukocyte adhesion deficiency,BLAD）基因的携带频率。共检测了来自全国14个公牛站的587头种公牛,发现BLAD携带者8头,携带率为1.36%。对现有公牛系谱信息分析显示,携带者公牛来自美国、加拿大和中国,其中6头携带者公牛可以追溯到共同祖先Osborndale Ivanhoe。此外,本研究还对我国荷斯坦牛遗传缺陷的控制和携带者公牛的利用提出建议。     

优选法在农业科学试验中的应用

利用数学原理.通过实例介绍了黄金分割优选法和菲波那契优选法在农业科学试验中的合理应用,减少了试验的次数,提高了工作效率.     

Effect of passive pneumoperitoneum on oesophageal pressure, cardiovascular parameters and blood gas analysis in horses

Reasons for performing study: Standing surgical procedures are being employed to an ever‐greater extent in horses. Pneumoperitoneum during abdominal surgery might adversely affect the work of breathing. Objectives: To determine whether development of pneumoperitoneum during abdominal surgery adversely influences the work of breathing. Methods: Eight healthy mature horses were equipped with carotid artery and thoracic vena cava catheters and an intraluminal manometry system. The following measurements were obtained before and at +5, +10, +15 and +30 min following establishment of pneumoperitoneum by paralumbar puncture using an 8 gauge needle: vital signs, oesophageal pressure, gastric pressure, arterial and central venous blood pressures, and arterial and mixed venous blood gas analyses. Results: Significant changes in oesophageal pressure, central venous pressure and results of arterial and mixed venous blood gas analysis were not detected. Arterial diastolic and mean pressures and rectal temperature increased slightly (P≤0.05). Conclusions: Passive pneumoperitoneum did not adversely affect breathing mechanics or haemodynamic variables under experimental conditions. Changes in arterial pressure could have occurred as a response to the passive pneumoperitoneum or be related to handling stress. Subtle variations in rectal temperature were not clinically relevant and likely resulted from stress associated with restraint. Potential relevance: It is unlikely that mature horses will develop signs of respiratory difficulty as a result of the development of passive pneumoperitoneum during standing laparoscopy.     

应用灰色关联度对白羊草生产性能的综合评价

对4个居群白羊草（Bothriochloa ischaemum）在晋中的生长适应性性状指标,包括干草产量、干鲜比、叶茎比、株高、秆粗、节数、叶片数、粗蛋白质等,进行了灰色关联分析。结果表明,在晋中地区生产性能表现最好的是太谷居群,其次为平定和代县居群,而平鲁居群的生产性能较低。各项指标的权重大小顺序为：粗灰分中性洗涤纤维酸性洗涤纤维秆粗节间长叶长粗脂肪单株干重叶宽株高叶茎比干鲜比粗蛋白质节数干草产量叶片数。     

桑树内生真菌的分离、鉴定及其多样性分析

用组织分离法从不同桑树品种的器官组织中共分离出内生真菌114株,经显微形态观察,鉴定114株内生真菌分别归属于镰孢霉属Fusarium、链格孢属Alternaria、柱霉属Scytalidium等21个属,表明桑树内生真菌具有丰富的生物多样性。不同桑树品种树体内的内生真菌分布有一定差异。同一桑树品种不同器官组织的内生真菌种类和数量差异较大,根中最多,茎中次之,叶中最少。其中:镰孢霉属为根中优势种群,链格孢属为茎、叶中的优势种群;丛梗孢属Monilia和镰孢霉属菌株在根、茎、叶中均能分离到,其它属的菌株只存在于其中的某一个或两个器官组织。研究结果有助于进一步探讨桑树内生真菌与生理活性物质的关系。