桑树省力化全年条桑收获法的研究

全年条桑收获留干 0 4～ 0 .6m ,一留多年 ,且全年收获条桑。经过小区近 10年的试验及几年的农村示范表明 ,该收获法的收获工效比收获叶片提高 2倍以上 ,小区 9年平均产量比传统的冬根刈收获法增长 9 7个百分点 ,条桑饲养大蚕成绩明显比片叶饲养好。留干几年后根刈 ,桑树的再生长不受影响     

三种配方日粮饲喂湖羊的育肥效果分析

设计三种能量与蛋白质水平不同的配方日粮饲喂4月龄湖羊羔羊,为期60d。结果发现,三种配方日粮对公羔的日增重有显著影响,但对母羊的日增重无显著影响(P>0.05)。用配方Ⅱ和Ⅲ日粮饲喂的湖羊公羔,日增重极显著高于配方Ⅰ(P<0.01)。三种配方日粮饲喂羔羊,料肉比分别为2.15∶1、1.99∶1和2.09∶1;投入产出比分别为1∶1.54、1∶1.62、1∶1.55。这些结果表明,配方Ⅱ日粮(能量14.18MJ/Kg,粗蛋白16.53%)饲喂育肥湖羊的效果最佳;而配方Ⅰ日粮(能量13.41MJ/Kg,粗蛋白17.89%)和配方Ⅲ日粮(能量14.13MJ/Kg,粗蛋白17.87%)的效果次之。     

Glutathione Peroxidase Activity and Erythrocyte Lipid Peroxidation as Indices of Selenium and Vitamin E Status in Young Pigs

A randomized, blocked 2³ factorial experiment was conducted with 48 pigs from sows fed a diet low in selenium and vitamin E. From 3 to 12 weeks of age the piglets were kept in single pens and fed a basic diet consisting mostly of barley, dried skim milk, soybean meal and dried yeast, and containing 55 µg selenium and 3 mg vitamin E per kg. The treatment factors — i.e. feed supplements — were 2 levels of Se (nil, 60 µg/kg), 2 levels of vitamin E (nil, 50 mg/kg), and 2 levels of the feed antioxidant ethoxyquin (nil, 150 mg/kg). Blood samples, collected at termination of the experiment, were examined for glutathione peroxidase activity (GSH-Px) and resistance against erythrocyte lipid peroxidation (ELP) to evaluate Se and vitamin E status, respectively. Analysis of variance showed the GSH-Px activity to be litter-dependent (P < 0.001) and influenced by selenium supplementation (P < 0.001) but not by the other supplements or by interactions between supplements. Resistance against ELP was influenced only by vitamin E supplementation (P < 0.001). GSH-Px and ELP thus seem to be valuable and simple methods for evaluating, respectively, Se status and vitamin E status in growing pigs.     

Selenium and vitamin E deficiency in pigs. II. Influence on plasma selenium, vitamin E, ASAT and ALAT and on tissue selenium.

The effect of dietary selenium (Se) and vitamin E (Vit. E) in pigs on Se and Vit. E in plasma and on Se in tissue from liver, heart, m. long, dorsi and m. psoas major was studied; and furthermore was the influence on the enzymes ASAT and ALAT studied.Two levels of Se were used, 0.03 and 0.06 mg Se per kg feed. Within each Se level 2 levels of Vit. E were used, 15 and 45 i. u. per kg feed. This resulted in 4 groups: 1. low Se and low Vit. E; 2. low Se and high Vit. E; 3. high Se and low Vit. E; 4. high Se and high Vit. E.Ten% of all pigs fed low Se, and 4% of the pigs fed low Se and high Vit. E diet died with severe symptoms of Se deficiency. None of the pigs fed the high Se diet died with such symptoms. Plasma Se determinations have been shown to indicate the Se status in pigs almost as accurately as liver Se determination. ASAT and ALAT enzyme determinations were not of any diagnostic value.There was a good agreement between dietary Vit. E level and the corresponding levels in plasma. Oxidized herring oil seems to enhance the Vit. E need.     

桑树实生苗培育技术

以桑树实生苗的培育介绍了桑树种子采集、育苗地选择、播种及育苗地管理的技术要点。     

宁夏西吉河北杨地膜覆盖育苗技术

针对河北杨在宁夏育苗成活率低的情况,总结了河北杨在西吉地区整地、做床、覆膜、插穗采集、催根处理、扦插、抚育管理和病虫害防治等育苗关键技术,为在该地区培育河北杨苗木提供技术支持。     

桑叶的营养成分和食用药用开发价值研究进展

综述近年来国内外对桑叶的化学成分及其食用药用价值研究进展,指出桑叶含有蛋白质、碳水化合物、矿物质、脂类、维生素、多糖类、黄酮类、生物碱、挥发油类等多种化学成分,还具有降血糖、降血脂、降胆固醇、降血压、清除自由基、抗衰老、抗肿瘤、抗病毒等药理作用。并指出了桑叶在药品和功能性食品研究开发领域中的广阔前景,为桑叶资源的合理开发利用提供了依据。     

不同果桑品种对低温胁迫的反应及抗寒性评价

在休眠初期,果桑极易受到秋季低温冻害。以14个果桑品种为材料,在低温胁迫下,测定与抗寒性相关的6个生理生化指标,结合相关性检验,采用隶属函数法进行抗寒性综合评价,以期筛选抗寒性强的优良品种。结果表明:14个果桑品种可划分为3级,其中I级高抗寒型3个品种,II级抗寒型7个品种,III级低抗寒型4个品种。     

秤锤树硬枝扦插繁育技术研究

研究不同基质材料、不同激素浓度、不同年龄插穗处理对秤锤树硬枝插穗扦插生根的影响。结果表明:全光雾试验条件下,植物生长调节剂BA、基质、树龄对扦插成活率均有影响,幼龄树木、混合基质和高浓度BA处理对秤锤树硬枝扦插最为有利。5a生硬枝作插穗,用1 000mg/L的BA速蘸插条基部,扦插在河沙∶珍珠岩∶泥炭=1∶2∶2的混合基质中,扦插生根率最高,可达90.34%。