Dot─ELISA检测猪生殖和呼吸综合征抗体的研究

用差速离心法提纯ＰＲＲＳ病毒，利用ＮＣ膜作为载体，在国内外首次成功建立了检测ＰＲＲＳ血清抗体的斑点酶联免疫吸附试验（Ｄｏｔ－ＥＬＩＳＡ）。抗原包被浓度为１００μｇ／ｍｌ，被检血清工作浓度为１∶１０，酶标兔抗猪ＩｇＧ工作浓度为１∶６００。对７２份北京地区猪血清分别用Ｄｏｔ－ＥＬＩＳＡ和ＩＦ检测，Ｄｏｔ－ＥＬＩＳＡ检测阳性率为３３．３％，ＩＦ检测阳性率为３０．６％，与ＩＦ符合率较高，对部分待检血清检测结果表明：６１份１９９１年进口美国猪血清阳性率为０％，１８２份１９９５年进口加拿大猪血清阳性率为４．９４％。本法不需特殊仪器，适用于基层兽医部门和猪场对该病的血清学诊断和流行病学普查     

树莓叶黄酮提取的正交试验和响应曲面法工艺优化对比

旨在为树莓叶黄酮的开发应用提供数据参考,通过正交试验与响应曲面法设计改良乙醇提取工艺,并通过HPLC建立树莓叶黄酮的色谱分离条件为:Agilent ZorBax SB色谱柱,流动相为1mg/mL乙酸-乙腈=72.5∶27.5,等度分离,柱温30℃,检测波长:257nm,完成树莓叶黄酮的初步分离,以及黄酮中芦丁含量的准确测定和验证。最佳提取工艺为:646mL/mL乙醇,料液比1∶12.5,41.9℃加热回流173.3min,最佳工艺所得提取率1.127%,响应曲面法最佳工艺提取率略高于正交试验法,且其工艺条件均较优于正交试验所得工艺,可为后期研发树莓叶芦丁兽用中药制剂提供理论参考。     

苏子降气汤对哮喘豚鼠引喘潜伏期及其行为学评分的影响

为观察和比较苏子降气汤对卵白蛋白(OVA)致敏豚鼠哮喘模型的治疗作用,随机将50只豚鼠分为5组,空白组、模型组、苏子降气汤高剂量组、苏子降气汤低剂量组、地塞米松组,每组10只.除空白组外,其余4组均用卵白蛋白致敏法制备哮喘豚鼠模型,造模成功后,用苏子降气汤或地塞米松治疗;第13天给药2h后,将各组豚鼠用雾化器予以1 g/L的OVA诱喘,记录各组豚鼠的“引喘潜伏期”、“行为学评分”以及“停止雾化诱喘后豚鼠从哮喘状态恢复到正常状态所需的时间”,连续诱喘3d并记录相关数据.结果显示,模型组和空白组相比,地塞米松组、苏子降气汤高、低剂量组均可不同程度延长豚鼠引喘潜伏期、降低其行为学评分、缩短停止雾化诱喘后豚鼠从哮喘状态恢复到正常状态所需的时间,具有显著性差异(P＜0.01),且苏子降气汤高、低剂量组上述效果接近地基米松组.说明苏子降气汤的确能够延迟哮喘的发作时间,并能减轻哮喘豚鼠发病的症状,提示苏子降气汤确实有良好的治疗哮喘作用.     

臭氧对空气消毒效果试验观察

臭氧是一种高效环保的空气消毒剂,为了探讨臭氧消毒应用于畜牧业空气消毒的可行性,进行臭氧对空气消毒效果试验。结果表明,在相对湿度60%～70%,消毒60 min,臭氧消毒的杀菌率可达到99.84%,说明臭氧是畜舍空气消毒较为理想的新型空气消毒剂,值得推广应用。     

不同盐碱化草地混播牧草对绵羊瘤胃发酵和日粮养分利用率的影响

为了研究不同盐碱化草地混播牧草对绵羊瘤胃发酵、养分消化率和氮平衡的影响,试验选用12只5月龄、(34.6±0.57)kg体重的德国肉用美利奴杂交一代公绵羊,随机分为4组,每组3个重复,对照组饲喂精料补充料+玉米青贮;处理Ⅰ、Ⅱ和Ⅲ组分别饲喂精料补充料+轻度、中度和重度盐碱化草地混播牧草(披碱草、碱茅和沙打旺),每只羊精料补充料平均日喂600g,粗饲料自由采食。结果表明,处理Ⅰ和Ⅱ组瘤胃pH显著低于对照组和处理Ⅲ组(P<0.05),而瘤胃总挥发性脂肪酸浓度显著高于对照组(P<0.05);处理Ⅰ、Ⅱ和Ⅲ组瘤胃液丙酸、丁酸、戊酸、异丁酸和异戊酸摩尔比显著高于对照组(P<0.05),而瘤胃乙酸摩尔比和乙酸/丙酸比例显著低于对照组(P<0.05)。各组间干物质和有机物质采食量差异不显著,处理Ⅲ组中性洗涤纤维采食量显著高于其他各组,处理Ⅲ组和Ⅱ组酸性洗涤纤维含量显著高于对照组(P<0.05)。干物质、有机物质、无氮浸出物和能量消化率变化规律一致,处理Ⅲ组显著低于处理Ⅰ和Ⅱ组,处理Ⅰ和Ⅱ组显著低于对照组(P<0.05)。粗蛋白质、粗脂肪、中性洗涤纤维和酸性洗涤纤维消化率由低到高依次为处理Ⅲ组、处理Ⅱ组、处理Ⅰ和对照组,组间差异均显著(P<0.05)。处理Ⅲ和Ⅱ组采食氮显著低于处理Ⅰ组,处理Ⅰ组采食氮显著低于对照组(P<0.05)。沉积氮和沉积氮/可消化氮均以处理Ⅱ组最低,依次为处理Ⅲ、处理Ⅰ和对照组,组间差异均显著(P<0.05)。结果说明饲喂轻度和中度盐碱化草地混播牧草促进了绵羊瘤胃发酵,但降低了饲料消化率和氮的利用率,而重度盐碱化草地混播牧草则降低了绵羊瘤胃发酵、饲料消化率和氮的利用率。     

猪肺炎支原体黏附因子基因R1R2区的克隆及表达

根据GenBank登录的猪肺炎支原体232株P97基因和J株黏附因子基因设计了1对引物，以我国猪肺炎支原体Z株(强毒株)基因组DNA为模板，通过PCR方法扩增了该株黏附因子基因的部分序列。经序列分析后，重新设计了1对带有EcoRI和HindⅢ酶切位点的引物，并经引物的定点突变，PCR扩增了Z株黏附因子的R1R2区。扩增产物经双酶切后克隆到表达载体pET-32(a) 中。该重组质粒经酶切鉴定后，将其具有正确阅读框架的重组质粒转化到大肠杆菌BL21(DE3)感受态细胞，37℃下经IPTG诱导表达，得到相对分子质量约29000的融合蛋白，表达量约为11％。     

Recombinant pseudorabies virus expressing P12A and 3C of FMDV can partially protect piglets against FMDV challenge

One of the crucial factors for evaluation of an effective genetically engineered vaccine is whether susceptible animals are protected from virus challenge after vaccination. In this study, a recombinant pseudorabies virus (PRV-P12A3C) that expressed capsid precursor polypeptide P12A and nonstructural protein 3C of foot-and-mouth disease virus (FMDV) was used as a vaccine. The expression of P12A3C and its immunogenicity and protective efficacy against FMDV challenge were measured. Humoral and cellular immune responses were evaluated after each immunization. Subsequently, each piglet was challenged with 1000 ID₅₀ (50% infection dose) FMDV serotype O, named OR/80, which is used to produce vaccine in China. PRV-P12A3C induced a high level of neutralizing antibody and FMDV-specific lymphocytes. Inactivated vaccine provided 100% protection, and the vector strain (TK⁻/gE⁻/gI⁻) showed no protection. PRV-P12A3C induced 60% protection, compared with piglets that were vaccinated with TK⁻/gE⁻/gI⁻. The severity of clinical signs for the remaining two piglets was lighter and the appearance of vesicles was delayed.     

盐碱草地不同改良措施对沙打旺氮代谢的影响

对盐碱草地分别以农家肥、农家肥+磷肥、糠醛渣和醋糟处理后种植沙打旺(Astragalus adsurgens)进行改良,测定其不同生育时期的氮代谢指标,以探讨盐碱地生物改良的机制。结果表明:不同改良措施下,不同生育时期沙打旺叶片各氮代谢关键指标差异显著(P<0.05),其大小顺序为现蕾期>开花期>返青期>结实期。相同生育时期不同改良措施下沙打旺叶片氮代谢关键指标均显著高于对照(P<0.05),大小顺序为醋糟>糠醛渣>农家肥+磷肥>农家肥>对照。不同改良措施下,沙打旺在现蕾期氮代谢最旺盛,而结实期代谢最缓慢;醋糟、糠醛渣、农家肥+磷肥及农家肥改良盐碱地均可提高沙打旺的氮代谢。     

The stimulatory effect of insulin-like growth factor-1 on the proliferation, differentiation, and mineralisation of osteoblastic cells from Holstein cattle

This study investigated the effect of exogenous insulin-like growth factor (IGF)-1 on the proliferation and differentiation of osteoblastic cells from Chinese Holstein cattle and the resultant bone nodule formation and mineralisation in vitro. The osteoblastic cells were isolated and cultured, then identified using Giemsa and alkaline phosphatase (ALP) staining methods. The effect of different concentrations of IGF-1 on cell growth was assessed by MTT assay. The ALP activity and osteocalcin (OC) concentration in the osteoblastic cells were measured by a colorimetric assay and a radioimmmunoassay, respectively. Calcium nodules were observed using alizarin red S stain, while the content of matrix calcium was determined by atomic absorption spectrophotometry. Cell proliferation in the cultures was stimulated by IGF-1 at concentrations ranging from 1 to 200 ng/mL, with the maximum effect observed at 100 ng/mL. This effect was observed from day 1 and peaked at day 5, but decreased at day 7. At concentrations of 10 ng/mL and 100 ng/mL, IGF-1 significantly induced ALP activity, OC level, matrix calcium content, and nodule formation of the osteoblastic cells by 20–180% (P < 0.05 or P < 0.01), compared to controls. The results suggested that IGF-1 is an anabolic agent for the proliferation, differentiation, mineralisation and calcium content of dairy cow osteoblasts, and could therefore act as a potential treatment for the metabolic bone diseases in these animals.