饲粮中添加功能性诱食肽对猪生长性能的影响

本文旨在研究猪饲粮中添加功能性诱食肽对猪只生长性能的影响.试验选取72头25±1日龄断奶仔猪(杜×长×大),按体重分成2个组,每个组6个重复,每个重复6头猪.对照组饲粮中添加100～ 150mg/kg的甜味剂,试验组添加120～300 mg/kg的功能性诱食肽.试验从仔猪断奶开始一直持续到出栏,试验分为五个阶段.结果表明:与对照组相比,添加功能性诱食肽组各个阶段的平均日采食量、平均日增重都有所提高,其中第一阶段和15～ 30 kg阶段生长性能效果最好,平均日增重分别提高13.71％、10.36％(P＜0.05).由此可见,在猪饲粮中添加诱食性功能肽可以提高猪只平均日采食量和平均日增重,改善生长性能.     

拜田净防治稻田杂草试验效果

为明确拜田净对水田杂草的防治效果,在田间采用大区对比法进行药效试验。结果表明,拜田净50%可湿性粉剂300g/hm2+草克星10%可湿性粉剂225g/hm2,在水稻移栽田一次性施用,对禾本科杂草防效100%,对阔叶杂草防效93%,对水稻不但安全,而且使水稻分蘖多、无效分蘖少、生长快,增产显著。比禾大壮+草克星或丁草胺+草克星效果好。     

猕猴桃溃疡病菌biovar 3群体MLVA分型技术的建立与应用

 丁香假单胞菌猕猴桃致病变种生物型3(Pseudomonas syringae pv. actinidiae biovar 3,Psa3)是猕猴桃溃疡病菌的世界流行群体,但仅在中国存在复杂的遗传多样性。开发适于Psa3群体分型的MLVA(multilocus variable-number tandem-repeat analysis)技术是探索中国Psa3起源与流行学特性的基础。本研究对7个Psa3菌株进行了全基因组测序,结合已公布的86个全基因组数据,进行比较分析发现,中国Psa3至少存在7个亚群;在各亚群间存在多态性的24个串联重复序列中,其中10个可以通过琼脂糖凝胶电泳区分开且变异指数合适,据此建立了适于Psa3的MLVA技术。采用该技术对分别来自贵州和陕西的62和9个Psa3菌株进行群体分型,分型结果与全基因组分析高度一致,证明该MLVA体系分型准确。MLVA分型结果表明:贵州主产区修文县Psa3有3个MLVA群体,其中亚群4的组内分化明显,代表最早发生的群体;而亚群 1和3的结构单一,且多在新果园发现,是新传入群体。总之,本研究建立了一套可用于Psa3群体分型的MLVA技术,将有助于解析中国各猕猴桃产区Psa3群体结构,以及探索中国Psa3的起源、传播和流行学特征。     

Growth,carcase and meat traits and gene expression in chickens divergently selected for intramuscular fat content

1. Changes resulting from divergent selection after 5 generations for intramuscular fat (IMF) content in breast muscle in a population of purebred Beijing-You chickens were investigated. Female chickens from lines selected-up (UL) and selected-down (DL) for 5 generations and random-bred controls (CL) were studied at 120 d of age.

2. In the UL, IMF in breast muscle (4.65%) was 1.38 times that in the DL (3.36%). The IMF content in leg muscle was also higher in UL compared to DL.

3. There were significant differences in growth, carcase traits and meat quality between the two selected lines. However, ultimate pH (pHu) was lower and lightness (L*) and yellowness (b*) were higher in breast muscles of UL birds compared to DL birds. Similar trends for pHu and L* value between UL and DL were observed in leg muscle.

4. Significant mRNA expression differences of the heart fatty acid-binding protein (H-FABP) gene between UL and DL were observed in breast muscle, and a negative correlation between expression of mRNA and IMF% in breast and leg muscles pointed to H-FABP as a potential selection candidate gene.     

规模化猪场优势血清型大肠杆菌对三种消毒剂的耐受性实验

选用目前常用的含碘、季铵盐消毒剂,对分离自青海4个规模化猪场的8株优势血清型大肠杆菌(O119、O149、O137、O144、O147、O141、O11、O60)进行了最小杀菌浓度、最小抑菌浓度的测定。结果表明:对此8株细菌,含碘消毒剂(杀毒宝典)杀菌浓度(1/2560)效果最好;双链季铵盐消消毒液(拜安)抑菌浓度(1/1280)效果最好;季胺盐类的表面活性消毒液(新洁尔灭)抑菌浓度(1/320)、杀菌浓度1/40),抑菌、杀菌效果较差。     

乳牛蹄病与矿物元素

对山西五大牧场的水、土壤以及健康乳牛和蹄病乳牛血液抽样测定了其钠、钾、钙、镁、磷、铁、锌、铜、锰等元素的含量。探讨了矿物元素与乳牛蹄病的关系。结果表明，低锌、低硫、高锰、高镁、高铁可能是乳牛蹄病发生的易感因素     

强化预算执行管理在农业科研单位财务管理中的作用

随着国家财政对农业科研单位投入的资金越来越大,要求项目预算执行管理中的监管力度也在不断加强,财务管理在项目预算执行管理中起着不可忽视的作用。该文通过六个方面阐述了农业科研单位在项目预算执行管理中需要做的工作,并指出要提高财政资金的使用效益,加快预算执行进度,依法、高效的使用财政预算资金,充分发挥预算执行管理在财务管理中的作用。     

秸秆还田对农田土壤风蚀影响的试验研究

土壤风蚀是形成沙尘暴导致土壤沙漠化的主要原因,它能够降低耕作层的保水性能和抗蚀能力,导致土壤肥力和生物生产量的下降,影响农业的可持续发展,对人类生存环境造成不同程度的危害[1]。土壤风蚀是一个复杂的物理过程,其根源除了严酷的自然气候外,有94·5%是人为掠夺式经营方式     

Comparison of different conditions inducing embryonic stem cells

AIM: To evaluate the different conditions inducing mouse embryonic stem cells (ESC) in vitro to differentiate into cardiomyocytes. METHODS: BRL conditioned medium was used to promote the growth of ESC and maintain them in an undifferentiated state. During the inducing process, retinoic acid (RA), DMSO, activin-A and TGF-β₁ were used as inducing reagents, and made up six kinds of differentiating medium. Then a three-step method inducing ESC cultured in hanging drops, in suspension and in plating was used to induce the differentiation of ESC. RESULTS: ESC were induced in vitro to differentiate into cardiomyocytes. Of all groups, the highest differentiating rate was observed in the group induced by activin-A (20 μg/L) and TGF-β₁ (2 μg/L). CONCLUSION: The inducing conditions including activin-A (20 μg/L) and TGF-β₁ (2 μg/L) is very valuable in inducing ESC differentiation into cardiomyocytes.     

沿海混盐水体褶皱臂尾轮虫的复合类群及其种群动态

于 2002年 7月至 12月对大连一沿海混盐水体中褶皱臂尾轮虫复合类群的种类组成和种群动态进行了研究。根据轮虫被甲的形态特点和测量结果, 鉴定出该复合类群中的 5个轮虫同胞物种: Bra chionusplicatilisYamamoto、B plicatilisMüller、B rotundiformisTschugunoff、B ibericusDalian、B hepato tomusDalian, 它们分属于L、SS和SM三大类群。对轮虫种群季节分布的研究结果表明, 该水体中褶皱臂尾轮虫复合类群的种群分布符合重叠模型假说, 通过应用灰色系统理论, 拟合计算出不同轮虫种群的增长率。文中讨论了轮虫复合类群形成的原因, 以及水体中生态因子对轮虫分布的影响。此外,文中还给出了这 5种轮虫形态分类的Fisher判别方程。