丁酸钠及其配伍在断奶仔猪中的应用效果   总被引：1，自引：0，他引：1  

丁斌鹰  韩祥东  胡麟 《饲料工业》2007,28(20):4-6

为研究丁酸钠及其配伍对断奶仔猪生长性能的影响,本试验选用(21±1)日龄断奶、(7.28±0.15)kg健康"杜×长×大"杂交仔猪150头,随机分为5个处理组,每个处理组3个重复(栏),每个重复10头仔猪,公母各半。试验日粮是在基础日粮基础上分别添加10%硫酸抗敌素预混剂600mg/kg(对照组)、0.1%丁酸钠(试验Ⅰ组)、0.2%丁酸钠(试验Ⅱ组)、0.1%丁酸钠+10%硫酸抗敌素预混剂200mg/kg(试验Ⅲ组)和0.1%丁酸钠+10%硫酸抗敌素预混剂400mg/kg(试验Ⅳ组)。试验期为14d。试验结果表明,在断奶仔猪日粮中添加丁酸钠及其与硫酸抗敌素配伍均显著降低断奶仔猪腹泻发生率(P<0.05),并有提高断奶仔猪的平均日增重和采食量、降低料重比的趋势(P<0.05)。且0.1%丁酸钠与10%硫酸抗敌素预混剂400mg/kg配伍使用对仔猪抗腹泻、促生长的效果最好。  相似文献   

刀切法在森林双重回归抽样调查中的应用初探     

鲁法典  韩峻 《河北林果研究》1999,14(3):216-220

为进一步 改进抽样 效果, 将 刀切法 结 合顺 序统 计 量应 用于 双 重回 归抽 样 中, 以 材 积为目的因 子, 胸径 为辅助因 子。结果 表明, 在 减少 二重 样本 ５０ ％ 的情 况下 , 与 普通 双重 回 归抽样相比 , 精度仍 达９８２ ％ 。因 此认为, 在林 相整 齐, 生长 正常 的 林分 中进 行 双重 回归 抽 样调查时, 利 用刀切法 , 可 在减 少 二重 样 本, 减少 外 业工 作 量 的情 况 下, 仍能 保 持 较 高 的精 度。另外, 对二重样 本单元和 单元数 的确定以 及刀切 法的局限 性进行了 讨论。  相似文献   

Effects of elevated CO2 on net photosynthetic rate of trees in Changbai Mountain     

王琛瑞  韩士杰 《林业研究》1999,10(4)

lntroductionAtmosphericconcentrationofCo2isrisingdra-maticaIIyandadoubIingofthepresentconcentrationwouIdoccurinmidnextcentury,duetoburnoffossilfuelanddestroyofforest(Gates1983,Tauszetal.1996).EIevatedatmosphericCO2willchangeitsgradientdistributioninforestecoboundary,andwillproduceagreateffectontreesandthewholeforestecosystem.Atpresent,studiesoneffectsofelevatedCozonplantshavebeenapopuIartopic,especiallyoncropsrice(BateretaI.199o).HaveIkaetal.(1984)hasgainedmanyachievementsonsoybean.How-e…  相似文献   

Friction velocity u* and roughness length z0 of atmospheric surface boundary layer in sparse-tree land     

Guan Dexin  ZHU Tingyao  Han Shijie 《林业研究》1999,10(4)

Sparse-tree land is one of the typical lands and can be considered as one typical rough surface in boundary layer meteorology. Many lands can be classified into the kind surface in the view of scale and distribution feature of the roughness elements such as agroforest, scatter planted or growing trees, savanna and so on. The structure of surface boundary layer in sparse-tree land is analyzed and the parameters, friction velocity u* and roughness length z0 are deduced based on energy balance law and other physical hypothesis. The models agree well with data of wind tunnel experiments and field measurements.  相似文献   

Improvement mechanism of bondability in UF-bonded reed and wheat straw boards by silane coupling agent and extraction treatments   总被引：4，自引：0，他引：4  

Guangping Han  Kenji Umemura  Shuichi Kawai  Hiromu Kajita 《Journal of Wood Science》1999,45(4):299-305

The effects of silane coupling agents and extractives on the wettability of reed and wheat straws were investigated. The inherent wettability of these materials was low but could be significantly improved by treating with silane coupling agents. The degree of improvement achieved by each silane coupling agent was different: Vinyl silane had almost no effect on wettability, epoxide silane was found to be more effective for reed straw, and amino silane was better for wheat straw. The wettability of these materials could also be improved by ethanol-benzene extraction, which resulted in more improvement in wheat straw than reed straw. The analyses of untreated reed and wheat straws by electron spectroscopy for chemical analysis (ESCA) revealed that there was much silicon on both the outer and inner surfaces of the former but only on the outer surface of the latter. The influence of hot-water extractives and silane coupling agents on the gelation time and pH of urea formaldehyde (UF) resin was also examined. The addition of extractives was found to increase the gelation time. Amino silane greatly retarded the gelation of OF resin, whereas epoxide and vinyl silanes had no influence on resin gelation. This retardation was found to be due to an increase in the pH of the resin.  相似文献   

A Real-time Expert System Based on Adaptive Predication of Process State     

CHAI Yi  HUANG Xi-yue  SHI Wei-ren  HUANG Han ming 《保鲜与加工》1999,(4):58-62

The combination of the measured real time state acquisition from the process with predictive process for the fature state is used to predicate the variable tendency for process state. This method is useful to avoid delay and enhance real time ability of the control information of the expert system. Also a described knowledge and structure of real time process state are proposed. This system can be applied to other kind of practice systems with slow time variable, uncertainty and delay.  相似文献   

玉米过氧化物酶和酯酶同工酶与杂种产量的关系   总被引：11，自引：0，他引：11  

戴景瑞  罗美中  韩雅姗 《作物学报》1989,15(3):193-201

以10个玉米自交系以及由它们组成的45个杂交种为材料,进行酶谱分析与单株粒重的测定。结果发现,玉米杂种 F_1的过氧化物酶同工酶 Px_4和酯酶同工酶 E_3的酶谱完全决定于其双亲。双亲酶谱相同,F_1与双亲一样;双亲酶谱不同,F_1出现双亲的互补酶谱。这两种酶的酶谱有差别的双亲杂交,能够产生高产的组合;这两种酶的酶谱没有差异的  相似文献   

河南旱作农区水分特征与节水农业途径     

韩慧君  孙铭伦  杜成林 《中国农业科学》1989,22(5):35-41

根据年降水量80%保证率、干旱频率和降水-蒸发差额分划出河南旱作农区范围,北起省界,南至沙、颍河。分析其降水、土壤水分和灌溉水资源等特征。指出平原以种植小麦为主并采用防旱轮作制,可充分利用自然降水;山区开展蓄水保土为中心的基本农田建设,为近期节水农业途径。  相似文献   

油松受松毛虫危害后恢复能力的研究   总被引：3，自引：0，他引：3       下载免费PDF全文

李镇宇  陈华盛  丛秀玉  韩义生  乔秀荣 《林业科学研究》1998,11(4):424-427

油松经人工模拟失去一定的量的１年生针叶后对第２年高生长,针叶长度有明显的影响：失杏越多,影响越大,经２ａ后其后高生长虽仍有差异,但均可恢复到正常生长状态,而失去少量２－３年生针叶后的油松具有有补偿和超补偿效应,失去１年生针叶后油松不具有补偿和超补偿效应。  相似文献   

侧柏人工幼林年生长动态及其与水热关系研究初报     

薄颖生  韩恩贤  罗伟祥 《林业科学》1998,34(5):120-126

侧柏人工幼林年生长动态及其与水热关系研究初报薄颖生韩恩贤罗伟祥（陕西省林业科学研究所杨陵７１２１００）关键词侧柏,人工幼林,生长动态,水分,热量,回归分析侧柏是黄土高原造林的优良树种之一［１～３］。过去由于对该树种的生物学、生态学及造林学特性等方面...  相似文献