Influence of condensed tannin on intake, digestibility, and efficiency of protein utilization in beef steers fed high concentrate diet

This trial was conducted to evaluate if the effect of condensed tannin (CT) is associated with a true protein source on intake, ruminal and total digestibility, ruminal digestion rate, protein efficiency, and microbial efficiency in beef steers fed high concentrate diet (87% of DM). Four Bos indicus steers (407 ± 12 kg of BW) fitted with rumen cannula were assigned to a 4 × 4 Latin square design, arranged in a 2 × 2 factorial arrangement. Treatments consisted of either inclusion (0.4% of DM) or exclusion of condensed tannin (CT) from quebracho extract (76% of CT) with or without the use of soybean meal (SBM) as source of true protein. The level of inclusion was calculated to provide a daily intake of 1 g/10 kg of BW of CT. Intake of DM and nutrients was not affected (P > 0.10) by CT inclusion. However, there was an effect (P < 0.10) of CT inclusion on ether extract digestibility. An interaction (P < 0.10) was observed between CT and SBM on ruminal digestibility and digestion rate of crude protein (CP): when mixed with soybean meal, CT decreased the ruminal digestibility and, consequently, reduced the digestion rate of CP. Intake of CP increased (P < 0.10) with the inclusion of SBM. No differences in DM passage rate were observed (P > 0.10) among treatments. Effects of the interaction (P < 0.10) between CT and SBM were observed on flux of rumen undegradable protein (RUP), metabolizable protein (MP), and on the ratio MP:CP. In the presence of soybean meal, the addition of CT increased (P < 0.10) the flux of RUP and MP, and improved the ratio MP:CP. The yield of microbial protein on the abomasum and the microbial efficiency did not differ among treatments (P > 0.10). There was no difference (P > 0.10) on the pH, VFA, and ruminal ammonia (N-NH₃) with the addition of condensed tannin. The N-NH₃ increased and the ruminal pH decreased with the inclusion of soybean meal (P < 0.10). The utilization of condensed tannin as an additive in beef cattle diets with high level of concentrate and soybean meal as a source of true protein implies positive effects on crude protein utilization, decreasing digestion rate and ruminal digestibility of crude protein and consequently increasing the levels of metabolizable protein, with no changes in the ruminal fermentation parameters.     

湘西虎杖抑菌成分提取及其抑菌活性研究初报

以乙醇作溶剂,对湘西虎杖抑菌活性物提取条件进行研究,通过抑菌实验得到最佳提取条件为A3B2C3,即90%乙醇、60℃、3h, 该条件下的提取物对细菌生长的抑制活性最强,但对酵母菌无明显的效果,对三种受试细菌的最小抑菌浓度(MIC)为0.25~ 0.5g/ml。提取物经85℃、100℃,15 min 或pH2~8 处理后仍具有较强的抑菌活性,其乙酸乙酯萃取物对三个菌都有较强的抑菌活性。     

印楝提取物在林业病虫害防治中的应用

印楝(Azadirachta indica)是适生于热带和亚热带地区的长绿乔木树种,它的果实、种子、种核、枝条、树叶、树皮及树液中都含有活性物质,可防治8目200余种农业、林业、仓储和卫生害虫。文章介绍了印楝素的作用机理,同时在抑制病原菌方面也有相关报道,具有广阔的市场开发前景。     

夹竹桃提取物对松材线虫致死性的研究

用夹竹桃的树皮和树叶的酒精提取物和水提取物对松材线虫有很强的毒性,尤其是叶片的水提取物对松材线虫的杀伤性极强。这对利用植物提取液来毒杀松材线虫提供了一个初步的结论。     

栀子黄色素浸提条件的优化选择研究

应用正交设计 L16（44×23）就栀子黄色素浸提的果实破碎度、浸提次数、浸提温度、浸提时间和液比共 5 个因子与浸取液中栀子黄吸光度、果胶量的相关性进行了试验研究，结果表明果实破碎度和浸提次数为影响光度显著效应因子，果实破碎度和浸提温度为影响胶量显著因子。在此基础上，选择出了果实破碎度 20 目、浸提时间 35 min、浸提温度 20 ℃、液比 4 ml/g、二次浸提为栀子黄色素浸提的较优条件。在此条件下，栀子黄色素浸提所得的液状产品得率为 15.5 %。     

印楝提取物防治桑天牛的林间试验

以桑天牛成虫Apriona germari Hope喜食的构树为引诱树6株，选取一块与周围树林相对孤立的杨树林为试验地，试验地面积约为0．13hm^2，设引诱树6株，胸径8～10cm。每年1次将2g含30％印楝素的印楝种核提取物配成制剂，注入构树中，进行防治桑天牛林间试验。结果表明：注药前，对照虫株率(57．50％)与处理虫株率(56．41％)之间差异不显著。注药1a后处理林的虫株率下降至38．46％，对照林的虫株率增加到70．00％；2a后，处理林的虫株率下降到23．08％，对照林的虫株率达82．50％。讨论了应用天然化合物防治林木害虫的优点和前景。     

THE QUICK DETERMINATION METHOD OF RESIN CONTENT IN LARCH WOOD

The resin content in larch wood is usually determined by the traditionalBenzene-Alcohol Extract Method(BAEM).In order to meet the requirement of production prac-tice,the authors present two simple quick determination methods,IR lamp method and hydrogenperoxide solution method.Compared with the results of traditional method,the results of newmethods are nearly the same as former,therefore,both two methods can reflect the change condi-tion of resin content in wood.     

3种棕榈藤藤材变色的研究

棕榈藤(rattan)是热带和亚热带森林中多用途植物,是仅次于木材和竹材的林产品,具有很高的经济价值(许煌灿等,1993;1999)。自古以来,藤主要用来制作家具,在我国藤家具制造业已有100多年的发展历史。藤家具美观、轻便、耐用,深受人们喜爱,产品畅销国内外。但是,藤材的变色影响了藤条的质量和等级,进而影响商品的外观,左右商品的价值。变色原因有多种,生物的(如微生物繁殖)、化学的(如金属离子、酸碱作用)及物理的(如光和热)等(村神哉等,1979;陆文达,1993;村神哉,2002)。藤材变色有霉菌引起的霉变色,还有因藤材及其制品长时间暴露而导致颜…     

四种植物提取物对斜纹夜蛾卵的毒杀效果

以斜纹夜蛾卵为研究对象．对雷公藤Tripter gium wilfordii茎、皂荚Gleditsia sinensis Lam．刺、苦参Sophora flavescens和博落茴Macleya cordata等4种植物材料的正已烷及乙酸乙酯提取物的杀卵活性进行了测定。结果表明：博落茴的乙酸乙酯提取物对斜纹夜蛾卵有较好的杀伤力,校正未孵化率高达95．63%;雷公藤的乙酸乙酯提取物和苦参的正已烷提取物对斜纹夜蛾卵的孵化也有明显的抑制作用。     

室温粉碎搅拌法从印楝种仁中萃取印楝素的研究

用快速粉碎搅拌的方法从印楝种仁中萃取印楝素,分别研究了萃取时间、溶剂的选择及用量对印楝素萃取产率的影响。优化的工艺条件为:208g去油后的印楝种仁(相当于300g印楝种仁),以750ml甲醇做溶剂,在快速粉碎搅拌下萃取21min即可以达到最高萃取产率,与微波辅助法、超声波法、浸提法相比,具有提取率高、设备和操作简单、节约溶剂、快速等特点。