努力构筑安全防线促进饲料工业健康发展——在中国饲料工业协会第五届大型企业联谊会暨2009饲料行业发展高层论坛上的讲话

今天,我们大家欢聚一堂,隆重举办中国饲料工业协会第五届大型企业联谊会暨2009饲料行业发展高层论坛,这是饲料行业的一大盛事.我谨代表农业部对会议的成功举办表示热烈的祝贺!近几年来,畜牧业发展很不平凡,难题多、任务重、压力大.     

日粮添加免疫生长促进剂C96对雏鸡若干血液指标的影响

选择１２０只１日龄ＡＡ商品健康雏鸡,随机分为４组,每组３０只。初步观察了日粮添加免疫生长促进剂Ｃ９６对血液中红细胞总数（ＲＢＣ）、比容（ＰＣＶ）、血红蛋白含量（Ｈｂ）、网织红细胞比例（ＲＣＣ）、白细胞总数（ＷＢＣ）等的影响。结果表明：肉雏鸡在１５ｄ时,日粮添加Ｃ９６为１１ｍｇ／ｋｇ,饲料的Ｃ９６组和疫苗－Ｃ９６组,与对照组和疫苗组比较,ＲＢＣ和Ｈｂ增高,ＷＢＣ显著下降,ＲＣＣ降低,ＰＣＶ无明显规律性变化;３０ｄ和４５ｄ时,添加Ｃ９６组和疫苗－Ｃ９６组的ＲＢＣ、Ｈｂ和ＰＣＶ,与对照组和疫苗组基本相近,ＷＢＣ和ＲＣＣ均比对照组和疫苗组低或明显低。但３０ｄ时疫苗组的ＷＢＣ比对照组高。整个试验期,ＲＢＣ、ＷＢＣ和ＰＣＶ随日龄的增长呈上升趋势,ＲＣＣ呈波动性下降。     

Chemical composition and microstructure of uroliths and urinary sediment crystals associated with the feeding of high-level cottonseed meal diet to water buffalo calves

The chemical composition and microstructure of seven uroliths and four urinary sediment samples associated with the feeding of high-level cottonseed meal diet to buffalo calves were examined by chemical qualitative analyses, scanning electron microscopy ( ), X-ray diffraction, and X-ray energy dispersive spectrometry ( ). Struvite was a major component of kidney stones and of some bladder stones. The kidney stone sample appeared cracked under low power under , aggregated into tiny balls under high power, and as a bladelike structure under even higher power. The bladder stone samples appeared finely granular or granular with various forms of prismatic crystals. The urinary sediments were prismatic crystals, with granules. The newly found prismatic crystals, which were rich in potassium and similar to struvite in crystal structure, were identified as potassium magnesium phosphate (KMgPO₄ · 6H₂O) in some bladder stones and urinary sediments. However, crystals which contained Mg and P only, which had been used for struvite identification, were not found by examination in urinary sediments from fresh urine samples of buffalo calves fed the high-level cottonseed meal diet.     

草原综合顺序分类法的新改进：Ⅰ类的划分指标及其分类检索图

根据全国２３５２个气象站３０年以上的气候资料以及其他资料，对草原的综合顺序分类法第一级分类的热量级，湿润度级指标进行了修正，设计了新的分类检索图，将地带性和非地带性的天然草地，以及人工草地的类，纳入到统一的检索图的中，并可进行计算机检索。     

辽西北暖性灌草丛类草原牧鸡治蝗效果试验

在辽西北暖性灌草丛类天然草原开展了牧鸡治蝗试验,通过对草原蝗虫防治效果、日捕食量、牧鸡日增重、牧草生产力水平及经济效益等指标进行测定分析,初步探索辽西北草原区牧鸡治蝗综合防治效果.     

利用耳组织、血液、牛奶样品检测牛病毒性腹泻病毒的比较

牛病毒性腹泻病以发热、口腔及消化道粘膜糜烂、腹泻为主要症状,可引起怀孕母牛流产或产畸型胎儿,给养牛业造成巨大的经济损失,该病已成为当前严重危害我国养牛业的传染病之一。由于大部分感染BVDV的牛不表现特征性的临床症状和病理变化,而且引起腹泻和消化道黏膜糜烂或溃疡的疾病很多,所以确诊需进行实验室检查。目前实验室检测BVDV的主要方法是利用美国IDEXX公司ELISA诊断试剂盒,通过BVDV抗原和抗体的检测区别牛群持续感染牛。用于检测BVDV的样品种类有许多种,绝大多数是采集血液(血清)或牛奶样品进行检测。本试验对奶牛进行耳组织采样,同时采集血液和牛奶,用三种样品在相同条件下同时检测BVDV抗原,用血清和牛奶样品检测抗体,比较样品的检测结果。结果表明,这三种样品检测结果具有一致性,且耳组织采样更宜于大面积筛查。     

不同单酶制剂混合检测对比研究

试验以木聚糖酶、纤维素酶、淀粉酶和酸性蛋白酶为对象,首先研究了酸性蛋白酶分别和其他3种单酶进行混合后酶活测定值变化情况,结果表明,酸性蛋白酶对其他3种单酶的检测结果没有影响;试验第二部分研究了4种单酶整体混合在一起后各单酶测定值的变化情况,结果表明,木聚糖酶测定值出现很大偏高,其他3种单酶测定结果未出现显著偏差;进行进一步论证试验表明,淀粉酶可能是使木聚糖酶测定结果偏高的原因。     

在线清筛机构在粉碎机中的运用

<正>1现有粉碎机的运行状态及分析物料经锤片打击破碎后加速作圆周运动,离心力的作用使物料脱离锤片的打击,并很快在筛片侧形成物料环,粗细物料的质量不同造成物料环的分层,粗料粒层紧靠筛片侧,细料粒层覆在粗料粒层上。如果无法破坏物料的环流层,不但影响大颗粒物料重返粉碎区,而且还影响细物料的过筛,     

氮硅添加对高寒草甸生物量和多样性的影响——以青藏高原为例

草地施肥多集中于添加氮肥与磷肥,很少涉及硅肥。硅作为对植物有益的一种元素,能提高植物对环境的抗性,促进植物的生长。本研究以青藏高原高寒草甸为研究对象,通过添加不同组合的氮肥和硅肥,研究群落地上生物量和生物多样性的变化。结果表明,氮肥和硅肥的添加均能提高群落的地上生物量,然而硅肥提高群落地上生物量的幅度远低于氮肥;在添加氮肥导致群落物种多样性下降的同时,添加硅肥可以缓解群落多样性下降的趋势;硅肥的生物学功能在群落水平上存在着最佳浓度效应。同时,我们推测硅肥在维持群落中杂草的存活率上发挥着积极的作用,并通过比较不同硅肥处理时,杂草生物量所占群落生物量比重的变化,支持了上述推测。     

Pyruvate kinase is necessary for Brucella abortus full virulence in BALB/c mouse

Brucellosis, caused by a facultative intracellular pathogen Brucella, is one of the most prevalent zoonosis worldwide. Host infection relies on several uncanonical virulence factors. A recent research hotpot is the links between carbon metabolism and bacterial virulence. In this study, we found that a carbon metabolism-related pyruvate kinase (Pyk) encoded by pyk gene (locus tag BAB_RS24320) was associated with Brucella virulence. Determination of bacterial growth curves and resistance to environmental stress factors showed that Pyk plays an important role in B. abortus growth, especially under the conditions of nutrition deprivation, and resistance to oxidative stress. Additionally, cell infection assay showed that Pyk is necessary for B. abortus survival and evading fusion with lysosomes within RAW264.7 cells. Moreover, animal experiments exhibited that the Pyk deletion significantly reduced B. abortus virulence in a mouse infection model. Our results elucidated the role of the Pyk in B. abortus virulence and provided information for further investigation of Brucella virulence associated carbon metabolism.