复合酶发酵玉米秸秆配置菌液饮水育肥羔羊对比试验

为了充分利用饲料资源,提高羔羊育肥效果,我们将玉米秸秆粉碎后,利用复合酶发酵饲喂羔羊,同时在饮用水中加入AM菌液对羔羊进行了育肥试验,结果试验组比对照组羔羊的采食量、饲料转化率、胴体重、净肉重和经济效益上都有明显提高（P〈0.05）,经过复合酶发酵处理的玉米秸秆饲喂羔羊对提高羔羊饲料报酬方面有很好的作用,在羔羊育肥过程中值得大力推广。     

恩拉霉素高产菌株的快速选育

为筛选恩拉霉素高产菌株,降低生产成本,以生产用Streptomyces-483为出发菌株,进行紫外-氯化锂复合诱变。以金黄色葡萄球菌为指示菌,用琼脂块法测定抑菌圈大小,筛选出84株突变株,经摇瓶初筛、复筛、5L发酵罐验证,最终获得4株高产突变株。筛选得到的4株高产突变株经稳定性考察完全适用于生产。     

复合有机铁对母猪繁殖性能和仔猪生长性能的影响

通过在怀孕后期和哺乳期母猪日粮中添加不同水平的硫酸亚铁和复合有机铁,以及肌注铁与否来考察复合有机铁对母猪繁殖性能和仔猪生长性能的影响。结果表明,与无机铁相比,母猪饲粮中添加复合有机铁可提高母猪产活仔率和断奶仔猪存活率,提高仔猪10日龄、21日龄体重;综合铁源、铁水平以及肌注补铁的效应,添加120 mg/kg复合有机铁,同时仔猪均辅以肌注补铁,可显著提高仔猪肌注7日龄和断奶时体重(P<0.05)。     

甘肃玉米茎腐病病菌禾谷镰孢复合种遗传多样性

为阐明甘肃省玉米茎腐病优势致病菌禾谷镰孢复合种地理群体的遗传多样性,2015年和2017年从甘肃省4个生态区采集茎腐病样本,经组织分离及鉴定,选取代表性禾谷镰孢复合种菌株114株,采用SSR和VNTR引物结合POPGENE version1.32及NTSYSpc 2.11,进行群体间遗传多样性及亲缘关系的聚类分析.结果...     

沿海混盐水体褶皱臂尾轮虫的复合类群及其种群动态

于 2002年 7月至 12月对大连一沿海混盐水体中褶皱臂尾轮虫复合类群的种类组成和种群动态进行了研究。根据轮虫被甲的形态特点和测量结果, 鉴定出该复合类群中的 5个轮虫同胞物种: Bra chionusplicatilisYamamoto、B plicatilisMüller、B rotundiformisTschugunoff、B ibericusDalian、B hepato tomusDalian, 它们分属于L、SS和SM三大类群。对轮虫种群季节分布的研究结果表明, 该水体中褶皱臂尾轮虫复合类群的种群分布符合重叠模型假说, 通过应用灰色系统理论, 拟合计算出不同轮虫种群的增长率。文中讨论了轮虫复合类群形成的原因, 以及水体中生态因子对轮虫分布的影响。此外,文中还给出了这 5种轮虫形态分类的Fisher判别方程。     

Solving Method for Soil Spring Stiffness of Shallow Shield Tunneling

Based on complex variable theory in plane elasticity, the equivalent spring stiffness is derived from the analytical solution by means of simplifying shallow shield tunneling to semi-infinite plane with hole, which is applied to response displacement method. The performances of the analytical solution are evaluated and compared with that of the deep shield tunneling through a series of selected various tunnel depths and soil Poisson's ratios. The relation of compression and shear spring stiffness is discussed. Meanwhile, two factors affected soil spring stiffness, tunnel depth and soil Poisson's ratio, are also analyzed. It is shown that soil spring stiffness of shallow shield tunneling is different from that of deep shield tunneling, and the ratio of compression and shear spring stiffness varies along shallow shield tunneling. It is also found that the value and distribution law of soil spring stiffness of shallow shield tunneling greatly depend on tunnel depth and soil Poisson's ratio.     

“空中拖拉机”在复杂山区防治蜀柏毒蛾试验

摘要：本文首次在地形复杂、地势陡峭的四川省梓潼县七曲山国家级森林公园运用AT-504飞机防治蜀柏毒蛾2—3龄幼虫,作业流量2400mL·hm,喷幅80m,平均雾滴密度为15个·cm,雾滴直径140～200μm,喷洒覆盖率达90％以上。结果表明：“空中拖拉机”在复杂山区的喷洒作业质量与在平原地区相比,没有明显差异。喷洒1．2％烟碱·苦参碱乳油和3％苯氧威乳油15天内蜀柏毒蛾虫口减退率达89．5％和88．0％,飞防效果十分显著。“空中拖拉机”不仅适合平原地区农业和林业飞机喷洒作业,而且适合复杂山区林业有害生物的飞防作业,具有效果好,成本低、效率高的优点,可以大面积推广应用。     

母、乳猪日粮中添加甘氨酸铁络合物的应用研究

试验研究了母、乳猪日粮中添加甘氨酸铁络合物的应用效果。母猪日粮中添加甘氨酸铁络合物60 mg/kg,乳猪日粮中添加甘氨酸铁络合物100 mg/kg,总产仔数、活仔数、初生窝重和初生均重分别比对照组提高了5.14%(P>0.05)、6.30%(P>0.05)、7.50%(P<0.05)和1.38%(P>0.05)。试验组仔猪日增重比对照组提高8.12%(P<0.05),而成活率则提高了2.52%(P>0.05)。母猪初乳铁含量、胎盘铁含量、乳猪脐带铁含量和乳猪血液铁含量分别比对照组提高了39.09%(P<0.05)、62.35%(P<0.05)、73.93%(P<0.05)和89.37%(P<0.05)。仔猪黄痢、白痢、副伤寒分别下降了84%、78.57%、20%。母猪的采食量提高了6.82%(P>0.05)。试验组的哺乳仔猪注射铁制剂与否,猪的肤色、毛色、可视黏膜的外观表象及增重没有显著性的差异,而对照组则有显著性的差异。     

Hip dysplasia and dog breeding

Summary

Hip dysplasia is considered to be one of the most serious problems in dog breeding. In the past 20 years the studies of, and the attempts to control, this condition have been directed mainly to the overall picture of the abnormality of the hips. The various efforts have resulted in a decrease in the incidence of HD in several breeds of dogs. For other breeds the results have not been very convincing, however. In some instances they are even said to be conflicting with other aims of breeding. Based on these data some separate studies have recently been performded in respect of the details of the disorders in the hip joints and of the heritability of these elements.

The present study concerns itself with the roots of the disorders as they are observed in the various breeds. A great variety of data indicates that selection within the canine species for specific morphological traits must be considered as one of the most important roots of the occurrence of HD. The collected data strongly indicate that improvements in the HD status in the various breeds can be reached by selection against specific disorders of the hip joints in these breeds.