畜牧产业结构调整影响因素分析

本文对畜牧产业结构影响因素进行了具体分析,认为自然资源环境、社会发展进程以及科技进步是产业结构的3大影响因素,其中自然资源环境是结构调整的基础,社会发展是动力,科技进步是支撑条件。     

Treatment of porcine oocytes with MEM vitamins during in vitro maturation improves subsequent blastocyst development following nuclear transfer

This study was carried out to investigate the effects of minimum essential medium (MEM) vitamins during in vitro maturation (IVM)/in vitro culture (IVC) of porcine nuclear transfer (NT) embryos on subsequent developmental capacity in vitro. Porcine cumulus-oocyte complexes (COCs) were divided into five groups, matured for 44 h in maturation medium with various concentrations of MEM vitamins (0, 0.05, 0.1, 0.2 and 0.4%), and observed for maturation rate. Also, COCs were matured in NUSU-23 media without MEM vitamins for 44 h and cultured in PZM-3 media with various concentrations of MEM vitamins (0, 0.05, 0.4 and 1.0%) for 6 days following nuclear transfer. Factorial (IVM/IVC) experiments were also performed in NCSU-23 medium with or without 0.05% MEM vitamins and PZM-3 medium with or without 0.4% MEM vitamins. They were then tested by examining in vitro development of the porcine reconstructed embryos. The maturation rates of the COCs treated with the MEM vitamins did not differ significantly among the MEM vitamin-treated groups. Addition of vitamins to culture medium did not affect development of porcine reconstructed embryos in vitro. However, addition of low concentrations of MEM vitamins only to maturation medium increased (P<0.05) the proportion of NT embryos developing into blastocysts compared with the control group. Addition of MEM vitamins to IVC medium did not enhance the developmental rate compared with the control group. Thus, addition of MEM vitamins to IVM medium could improve subsequent blastocyst development of porcine NT embryos.     

Molecular cloning and functional analysis of goose interferon gamma

The cDNA for goose interferon gamma (goIFN-gamma) was cloned from PHA-stimulated goose peripheral blood mononuclear cells (PBMCs) by RT-PCR. This cDNA encodes a 19-amino acid signal peptide and a 145-amino acid mature protein, which shares a high homology with duck IFN-gamma. Recombinant mature goose interferon gamma (rgoIFN-gamma) generated from both prokaryotic and eukaryotic expression systems effectively inhibited the replication of goose paramyxovirus and recombinant vesicular stomatitis virus in vitro. These antiviral activities were abrogated by rabbit anti-rgoIFN-gamma antibodies in vitro. Furthermore, rgoIFN-gamma stimulated goose peritoneal macrophages to produce nitric oxide (NO) in vitro, demonstrating its macrophage activating factor (MAF) activity. Therefore, the availability of bioactive rgoIFN-gamma and its specific antibodies provides valuable tools for studying T cell immunity in geese.     

猪用发酵床的研究与应用

新型微生物发酵床养猪技术是一种新兴的无公害养猪技术,它可有效地解决猪生产中的粪便处理和环境污染问题,改善猪的福利状况,利于猪只的生长和发育,其环保性和经济性明显优于集约化,规模化养猪方式.本文介绍了微生物发酵床的概念、分类和工艺流程,讨论了其技术要点和应用效果,并对其发展前景进行了展望.     

四氯联苯对鸡胚性腺原始生殖细胞的毒性影响

采用四氯联苯处理发育至Ⅹ期的白来航鸡种蛋,孵化5.5天后取出胚胎进行全固定,用石蜡切片和PAS染色(高碘酸希夫试剂)研究四氯联苯对鸡胚性腺原始生殖细胞(PGCs)的影响.结果表明,四氯联苯对发育至5.5日胚龄的鸡胚性腺PGCs数量和结构有明显影响,但雌二醇处理的5.5日胚龄鸡胚PGCs数量变化不显著,其结构无明显变化.表明四氯联苯对5.5日胚龄的鸡胚性腺PGCs的影响主要来自于其毒性作用.     

乳牛口服大量β-胡萝卜素对维生素D3及钙磷代谢的影响

６头健康成年荷斯坦乳牛被随机均分为２组。试验组牛第１周每头口服β－胡萝卜素２３．０ｇ,以后每周每头口服１１．５ｇ,对照组不做任何处理。试验期共８周。结果表明,试验组乳牛血清钙及无机磷水平呈下降趋势;血清维生素Ｄ３活性代谢产物２５－ＯＨ－Ｄ３和１,２５－（ＯＨ）２－Ｄ３均呈现明显下降;至第５周末,血液β－胡萝卜素水平最高,２５－ＯＨ－Ｄ３水平下降非常明显。据此认为,乳牛对β－胡萝卜素的吸收存在一阈值,大剂量的β－胡萝卜素进入机体,可能直接干扰维生素Ｄ３的羟化,使其活性代谢产物呈下降趋势,但由于吸收阈值的存在,其对维生素Ｄ３和骨骼钙磷代谢的干扰作用可得到一定程度的减缓。     

细叶百合低温解除休眠过程中鳞茎内糖分及相关酶的研究

通过低温处理打破细叶百合鳞茎休眠,探讨细叶百合鳞茎解除休眠过程中的糖类化合物及蔗糖、淀粉代谢酶的变化规律。结果表明,鳞茎休眠解除过程中伴随着旺盛的糖类代谢活动,淀粉含量下降,淀粉酶活性升高。内层鳞片在冷藏60 d时可溶性糖含量达到峰值,贮藏前期,蔗糖含量,蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)活性上升,SPS和SS协同控制蔗糖代谢及转运。冷藏条件下鳞片及顶芽内淀粉向可溶性糖方向代谢过程中促进了腺苷二磷酸葡萄糖焦磷酸化酶(AGPase)活性的增加。各种淀粉代谢相关酶在鳞茎冷藏不同时期和不同部位的作用规律不同。鳞茎各个部位总可溶性糖含量与蔗糖、葡萄糖含量及淀粉磷酸化酶(SP)、SS、α-及β-淀粉酶活性都存在显著或极显著的正相关性。糖类代谢成为鳞茎休眠解除的物质基础。     

加拿大披碱草×披碱草杂种F1的生育及细胞遗传学研究

研究加拿大披碱草与披碱草种间杂种 F1 的生长、形态、花粉育性和细胞学。结果表明 ,杂种 F1 生长势明显超过双亲 ,平均株高 14 9.31cm,穗型呈双亲中间型 ,株型偏向母本 ,生育期偏向父本 ,花粉可育率 1.71% ,自然结实率0。杂种 F1 为五倍体 (2 n=5 x=35 ) ,其 PMCM 平均染色体构型为 19.0 14 +7.4 5 +0 .2 8 +0 .0 2 ,后期 有落后染色体和染色体桥等不规则现象     

膀胱无细胞基质在青紫蓝兔组织工程膀胱替代手术中的应用研究

研究膀胱无细胞基质（bladder acellular matrix graft,BAMG)在兔组织工程膀胱中的应用。按文献改进方法制作BAMG，从兔膀胱中分离出上皮细胞和平滑肌细胞，体外培养约4周，与无细胞基质材料复合成组织工程膀胱，对同一兔实施膀胱次全切术，用组织工程膀胱替代。术后进行膀胱造影，组织切片检查，提示组织工程膀胱功能良好。本方法获取的BAMG可用于兔的组织工程膀胱替代手术。     

多角体蛋白基因核苷酸序列对HBsAg(PreS2+S)在家蚕中表达的作用

应用PCR突变的方法 ,在乙肝病毒表面抗原 (HBsAg)前S2序列的 5’端融合了BmNPV多角体蛋白基因5’端的 12个碱基 ,获得了融合乙肝表面抗原中蛋白基因 (HBMp) ;通过同源重组将其插入到BmNPV基因组多角体启动子后 ,构建了重组杆状病毒BmPAK HBMp。用重组病毒BmPAK HBMp和BmPAK HBM(带有非融合乙肝表面抗原中蛋白基因 )感染家蚕细胞及蛹 ,对两种病毒的表达产物用ELISA进行了跟踪检测 ,结果表明融合蛋白比非融合蛋白HBsAg活性提高了 6 0 %～ 80 % ,作为HBsAg构成部分的PreS2抗原性提高了 8～ 10倍 ;并且HBsAg和PreS2 Ag表达的时相曲线不同 ,PreS2 Ag的表达量比HBsAg早 1～ 2d达到最大值。ELISA检测和Westernblotting分析表明 ,多角体基因序列的存在更有利于中蛋白全基因 (PreS2 +S)的表达。