Effects of Inhibition of Different Rumen Microbial Activity on Rumen Fermentation and Fatty Acid Metabolism in Buffaloes

This study was aimed to evaluate the effects of inhibiting rumen bacteria,fungi and protozoa with adding linoleic acid and linolenic acid on in vitro rumen fermentation and fatty acid metabolism in buffaloes.Both fatty acids were supplemented with substrate and roughage (3:7) at the rate of 3% on dry matter (DM) basis in an in vitro batch culture system,there were 5 repetitions for each group.At the same time,four groups were set up:Control group and inhibition groups of protozoa,bacteria and fungi.After 24 h of incubation,total gas production,CH₄,pH,VFA,NH₃-N,MCP and LFA concentrations were measured.The results showed that:①With the addition of linolenic acid,compared with control group,the gas production decreased significantly after inhibition the growth of bacteria and protozoa,CH₄ production increased significantly after inhibition of the growth bacteria and fungi,and CH₄ production decreased significantly after inhibition of the growth protozoa (P<0.05).With the addition of linoleic acid,compared with control group,the gas production decreased significantly after inhibiting the growth of bacteria,fungi or protozoa,and CH₄ production was significantly lower than other groups after inhibition of protozoa (P<0.05).② After inhibiting the growth of bacteria,fungi or protozoa,the pH and MCP concentration were affected significantly with the addition of linolenic acid (P<0.05),there was no significant effect on NH₃-N concentration with the addition of linoleic acid (P>0.05).③ Compared with control group,the content of acetic acid and propionic acid was reduced significantly after inhibiting the growth of bacteria,fungi or protozoa (P<0.05).The butyric acid was reduced significantly after inhibiting the growth of bacteria with the addition of linolenic acid (P<0.05).The butyric acid was reduced significantly after inhibiting the growth of bacteria,fungi or protozoa with the addition of linoleic acid (P<0.05).④ Compared with control group, the concentrations of C11:0, C12:0, C13:0, C14:0, C14:1n5, C15:1n5, C16:1n7, C16:0, C18:3n3, C18:2n6c, C18:0, C20:2n6, C20:3n6, C20:1, C20:3n3, C20:0, C21:0, C22:6n3, C22:2n6, C22:0 was reduced significantly after inhibiting the growth of bacteria with the addition of linolenic acid, the concentrations of C12:0, C13:0, C14:0, C15:0, C16:1n7, C16:0, C17:0, C18:3n6, C18:3n3, C18:2n6c, C18:1n9t, C18:0, C18:2(cis-9,trans-11), C18:2(trans-10,cis-12), C20:2n6, C20:1, C20:0, C21:0, C22:6n3, C22:0, C23:0, C24:1n9, C24:0 was reduced significantly after inhibiting the growth of bacteria with the addition of linoleic acid (P<0.05).The results revealed that the addition of linoleic acid and linolenic acid could significantly manipulate in vitro rumen fermentation parameters,CH₄ yield and fatty acid composition after inhibiting the growth of bacteria,fungi or protozoa.Protozoa greatly contributed to total gas and CH₄ production while bacteria significantly affected rumen fatty acid metabolism.     

基因芯片技术及口蹄疫病毒基因芯片研究进展

口蹄疫的暴发与流行给世界各国的畜牧生产、社会经济和国际贸易构成严重威胁并造成巨大的经济损失，经典的血清学和PCR检测方法越来越不适应进出口动物检疫的快速、准确、高通量的要求。建立一种快速的诊断方法，使其在很短时间能够区别各血清型口蹄疫和其他水泡性疾病是非常必要的。口蹄疫病毒基因芯片包括155个寡核苷酸探针，总长35bp-45bp，设计在VP3-VPl-2A区，既有共有的病毒型别，也包含特异的血清型别。这项技术的优点是能在单一的芯片上检测多元病原体。     

产肠毒素大肠埃希茵主要黏附素的研究进展

产肠毒素大肠埃希茵的主要黏附素抗原有K88、K99、987P和F41，在发病学和免疫学上扮演着重要的作用。文章就其理化特性、生物学特性、分子生物学特性及主要检测方法进行综述。     

关于如何提高森林管护质量的几点意见

文章根据当前形势对林业工作的要求,指出森林管护方式须创新,并指出这方面工作中现存的几个问题及解决办法。     

河北省退耕还林工程社会经济效益分析

退耕还林工程是我国投资规模最大的生态工程,同时,它又是我国生态工程中涉及面最广、工序最复杂的生态工程,面对这样的工程建设,必须要通过科学的效益分析和评价工作,得出工程建设各方面的科学数据,保证工程建设顺利健康地发展。     

论土地资源管理专业的特色建设与发展

以师范院校工科土地资源管理专业建设为基础，针对大测绘的学科基础，提出具有特色的土地资源管理专业建设思路，并在人才培养目标的确定、课程培养体系的设置、实践教学改革与实践基地的建设、师资队伍建设、教育与教学研究等方面给出特色专业建设的基本途径与方法。     

小叶丁香栽培技术探讨

陈述了小叶丁香的分布特点、形态特征和生物学特性,介绍了青海省当地居民常用的几种小叶丁香的栽培繁育方法。     

Expression of IGFBP2 and IGFBP4 in hepatocytes with experimental injury

AIM:To explore the mechanism of IGFBP2 and IGFBP4 in hepatocytes with injury induced by TNF-α and TGF-β1. METHODS:Human hepatocyte line (HL-7702) was cultured in vitro and treated with TNF-α or TGF-β1 for 24 h. The expression of IGFBP2 and IGFBP4 was detected by immunochemistry staining. The inhibition ratio of hepatocytes was detected by MTT assay. HL-7702 was treated with TNF-α at concentration of 20 μg/L for 48 h, then the apoptosis of hepatocytes was detected by both Annexin-V /PI and TUNEL assay. RESULTS:The expression of IGFBP2 and IGFBP4 in TNF-α or TGF-β1 treated groups was significantly higher than that in control group (P<0.05). The positive staining of IGFBP2 and IGFBP4 in TNF-α (20 μg/L) treated groups or TGF-β1 (4 μg/L) treated groups was the strongest among all groups. A positive correlation was found between IGFBP2 or IGFBP4 and inhibitory ratio of hepatocytes (P<0.05 or P<0.01). Compared with normal control group, the percentage of apoptosis markedly increased in TNF-α (20 μg/L) treated group (P<0.01). CONCLUSION:IGFBP2 and IGFBP4 involved in the injury process in hepatocytes, indicating an important role in injury of hepatocytes induced by TNF-α or TGF-β1.     

Co-γ-Fe_2O_3中包钴层的TEM研究

用自穿孔方法制得了Ｃｏ－γ－Ｆｅ２Ｏ３作高分辨电镜分析用的火棉胶微栅支持膜。对磁粉颗粒的ＥＤＳ线扫描表明Ｃｏ铁氧体主要分布在以γ－Ｆｅ２Ｏ３为芯的表面层，高分辨电子显微像表明表面层Ｃｏ铁氧体的结晶方向为［１１０］平行于长轴，其厚度在２ｎｍ左右，ＣｏＦｅ２Ｏ４外延生长取向并非与芯部γ－Ｆｅ２Ｏ３完全一致。     

不同杀菌剂对蔬菜灰霉病防治效果研究

在蔬菜灰霉病的防治过程中，存在灰霉病易产生抗药性．以及农资市场上农药种类繁多，药效不一等问题。为此，为了给无公害蔬菜生产需要选择适合的药剂品种，通过田间药效对比试验，综合评价参试药剂对灰霉病的田间防治效果，为灰霉病有效药剂防治提供依据。