猪苹果酸酶1基因5′调控区的多态性、遗传效应及功能分析

苹果酸酶1（malic enzyme 1,简称ME1）是机体内源性脂肪酸合成的关键酶,与生物体脂肪酸合成效率之间存在密切相关,猪的脂肪沉积能力与ME1的表达水平有关。为了研究该基因在转录水平上的表达调控,本试验分别用PCR、实时荧光定量RT-PCR（qPCR）和定点突变等方法,克隆了猪ME1基因5′调控区,分析了其多态性与猪背膘厚及脂肪组织中ME1mRNA表达水平的关系,还通过构建不同删除载体分析了该基因5′调控区的功能。结果表明,在猪ME1基因5′调控区的-486位点和-1 068位点分别有一个由C到T和由G到A突变产生的SNP,后者与商品猪的背膘厚关联显著（P〈0.05）。qPCR检测结果显示,在-1 068位点,等位基因G有增加ME1mRNA表达的趋势,接近显著水平（P=0.051 8）。删除试验结果显示,该基因的5′调控区614～717bp和263～405bp区段分别有增强和抑制猪ME1基因表达的顺式元件。     

Predicting the Classes and Distribution of Salt-Affected Soils in Northwest Libya

Sodicity and salinity can adversely affect soil structure and are common constraints to plant growth in arid regions. Current remote sensing techniques cannot distinguish between the various classes of salt-affected soils. Field and laboratory measurements of salt-affected soils are time-consuming and expensive. Mapping of the salt-affected soils can be used in soil conservation planning to identify regions with different degrees of limitations. There is a need to use existing field and laboratory measurements to create maps of classes of salt-affected soils. The objectives of this study are to classify salt-affected soils, use existing field data to interpolate and validate geospatial predictions of the classes of salt-affected soils using Geographic Information Systems (GIS), and create maps showing the different classes and distribution of salt-affected soils. The classification framework for salt-affected soils is based on electrical conductivity (ECe), soil pH and the sodium adsorption ratio (SAR), and provides four degrees of limitations to salt-affected soils: slight (normal soils), moderate (saline soils), severe (sodic soils), and extreme (saline-sodic soils). Spatial interpolation of the field data from northwestern Libya was verified by cross-validation, and maps of the salt-affected soils in the region were created. The majority of soils in this region of Libya are normal (slight degree of limitation). Twenty percent of the topsoil is saline-sodic (extreme degree of limitation). Land use recommendations and rehabilitation strategies can be developed from such maps of salt-affected soil classes. The methodology followed in this study can be applied to other arid regions around the world, particularly in developing countries where budgetary constraints limit detailed field and laboratory measurements of sodicity and salinity.     

22～42日龄黄羽肉鸡饲粮代谢能需求参数的研究

为研究不同性别22～42日龄黄羽肉鸡饲粮代谢能需求参数,用1600只21日龄岭南黄鸡进行了试验。采用2(性别)×5(代谢能水平)因子试验设计,通过向玉米—豆粕型基础日粮中添加不同剂量植物油、沸石粉和玉米芯粉,配制成5种含不同代谢能水平的试验饲粮,代谢能水平分别设置为:11.715、12.134、12.552、12.970、13.389MJ/kg。试验期21天,通过观测饲粮代谢能水平对试鸡生长性能、胴体品质、空体成分、能量和粗蛋白质沉积率、肌肉脂肪含量以及部分血液生化指标的影响,确定不同性别22～42日龄黄羽肉鸡饲粮代谢能需求参数。试验结果表明:在本试验条件下,根据不同评价指标确定的22～42日龄黄羽肉鸡饲粮代谢能需求参数略有不同,雌、雄黄羽肉鸡的最适饲粮代谢能水平基本一致。以生长性能为评价指标时,雌、雄试鸡结果一致,为12.958MJ/kg;以胴体品质和能量、粗蛋白质沉积率为评价指标时,得到的结果一致,为12.122MJ/kg;根据试鸡血清胆固醇、甘油三酯和尿素氮浓度确定的结果一致,为12.540MJ/kg;以空体成分为评价指标时,得到的雌、雄试鸡最适饲粮代谢能水平分别为12.540和12.958MJ/kg;以肌肉脂肪含量为评价指标,确定雌、雄试鸡饲粮代谢能最适需要量分别为12.540和12.122MJ/kg。综合考虑本试验根据不同判据指标得到的结果,确定     

汽车发动机智能启停系统技术研究

介绍了整车姿态角定义、测量方法和校验标准,通过实例分析整车姿态出现较大偏差时的原因分析思路及控制方法,并列举出影响整车姿态的几大关键因素,指出整车姿态设计时需重点关注的事项。     

日粮能量和蛋白质水平对5～10周龄仔鹅生产性能的影响

选用4周龄扬州鹅180只,以能量和蛋白质为试验因子,采用2因素3水平设计,研究日粮能量和蛋白质水平对生长期扬州鹅生产性能的影响。研究结果表明:①10周龄体重和日增重各组间差异不显著(P>0.05),屠宰指标间无明显规律。②对体重、日增重、屠宰率和腿肌率的影响,均是互作>能量>蛋白质,其中互作和能量对腿肌率的影响极显著(P<0.01);对半净膛率和全净膛率的影响,均是能量>互作>蛋白质,且影响均不显著(P>0.05);对胸肌率的影响,是能量>蛋白质>互作,且影响不显著(P>0.05)。③第7组(低能高蛋白组)在生长性能和经济效益方面均较佳。因此,推荐5￣10周龄仔鹅日粮能量、蛋白质水平分别为10.50MJ/kg、17%。     

Improvement of reproductive indices,lysozyme activity,and disease resistance in live‐bearing ornamental fish,Poecilia latipinna using Artemia supplementation with treated yeast cell,Saccharomyces cerevisiae

In the present study, the effects of Artemia supplemented with 2‐β‐mercapto‐ethanol (β‐ME) treated yeast cell, Saccharomyces cerevisiae, on growth and reproductive performance, lysozyme activity, and disease resistance to Aeromonas hydrophila of freshwater ornamental species, Poecilia latipinna, were investigated. Within 60 days, molly fish were fed with three treatments including commercial food (T1), un‐supplemented Artemia (T2), and Artemia supplemented with β‐ME‐treated yeast cell (at concentration of 4 × 10⁷ CFU/L of water) (T3). After the feeding period, the fish were exposed to 100 μl of a suspension (1.1 × 10⁷ cells/ml) of A. hydrophila (BCCM5/LMG3279) and the cumulative mortality rates were recorded for 12 days. No significant difference was found between survival rate and growth performance of P. latipinna except for weight gain that was higher in fish fed through Artemia supplemented with β‐ME‐treated yeast cell compared to control group. Fecundity rate was significantly improved in fish fed using T3 with the maximum amount of 49.5 ± 2.29 per female (p < 0.05). Besides, lysozyme activity was significantly increased in group 3 (p < 0.05). Moreover, lowest fish mortality was significantly observed in this treatment (p < 0.05). In addition, the number of colonies formed by yeast cell in T3 (634 × 10³ CFU/g intestine) showed significant difference with other treatments (p < 0.05). In sum, Artemia enriched with β‐ME‐treated yeast improved reproductive indices, immune responses, and resistance against A. hydrophila of P. latipinna.     

几种绵羊常用粗饲料GI的测定及其代谢能模型化研究

在测定五类九种粗饲料及三个混合粗饲料的常规成分基础上,实测了它们的粗饲料分级指数(GradingIndex,GI):大青山草地早熟禾3.4758、沙打旺3.3731、苜蓿1.7202、混粗C21.1797、青干草1.1029、混粗C10.7852、羊草0.5684、玉米青贮0.4152、玉米秸秆0.1985、谷草0.1728、混粗D0.0805、苏丹草0.0687,并就GI与饲料相对值(RelativeFeedValue,RFV)对粗饲料品质的分级进行了比较,表明GI要优于RFV,同时证明:GI还可以用于混合粗饲料的优化与牧草刈割期的确定。本研究建立了预测粗饲料ME的模型:ME(MJ/kg)=-11.7492+0.5959IVDMD(%)-0.0044[IVEMD(%)]2。     

Use of fermented milling by-products as functional ingredient to develop a low-glycaemic index bread

Selected Lactobacillus plantarum DSM 32248 and Lactobacillus rossiae DSM 32249, isolated and identified from wheat germ, were used to ferment a milling by-products mixture. Lactic acid bacteria metabolisms improved the functional properties of wheat bran and germ, which are considered important sources of functional compounds. Wheat breads were manufactured using 15% (w/w) of fermented (and unfermented) milling by-products, and compared to baker’s yeast wheat bread manufactured without the addition of milling by-products. The use of the fermented ingredient improved the biochemical, functional, nutritional, textural, and sensory features of wheat bread, showing better performances compared to the solely use of wheat flour. Protein digestibility, nutritional indexes, and the rate of starch hydrolysis markedly improved using fermented milling by-products as ingredient. Enriched bread was also characterized by high content of dietary fibre and low glycaemic index determined in vivo.This study exploited the potential of fermented milling by products as functional ingredient. According to the Regulations the bread made under this study conditions can be defined as “high fibre content” and “low glycaemic index”. A number of advantages encouraged the manufacture of novel and healthy and functional leavened baked goods.     

5%去甲斑蝥素微乳剂对小菜蛾杀虫活性研究

【目的】明确5%去甲斑蝥素微乳剂对小菜蛾的田间防治效果。【方法】采用浸叶法,测定了5%去甲斑蝥素微乳剂对小菜蛾的室内毒力;选用不同剂量5%去甲斑蝥素微乳剂和不同施药时期进行田间防治试验,观察该药剂对小菜蛾的田间防治效果。【结果】5%去甲斑蝥素微乳剂对小菜蛾3龄幼虫具有较高毒力,24h的致死中浓度(LC50)为85.10mg/L。在田间施用剂量为111.11~138.89g/hm2时,5%去甲斑蝥素微乳剂对小菜蛾药后7d的防效可达90%以上;进一步用111.11g/hm2 5%去甲斑蝥素微乳剂在小菜蛾不同龄期施药,结果表明,在1龄幼虫盛发期施药药效最好,7d后对小菜蛾的防效可达90.96%。【结论】5%去甲斑蝥素微乳剂在室内和田间对小菜蛾均具有很好的控制效果,具有防效高、持效时间长和安全等优点,有产业化开发前景。建议在甘蓝处于包心初期施用5%去甲斑蝥素微乳剂,施用剂量以111.11g/hm2为宜。     

四川水牛杂交改良研究

四川于1971年开始引进摩拉种公牛杂交改良本地水牛,至1985年已约有杂交水牛55,000头。杂交一代水牛在体格、役用能力、产肉力及产乳力上均优于本地水牛。第一代杂交母水牛第一胎泌乳期产奶置为1096.65公斤,含脂率8.5％,相当于1842.37公斤标准奶,而本地母水牛仅产奶441.41公斤,含脂率9.75％,相当于812.19公斤标准奶,杂交一代母水牛第一泌乳期产奶量较本地母水牛高127‰故水牛为一种潜在的遗传资源,杂交育种是向乳用方向改良本地水牛的有效方法。