运用模型分类法分析9个地方鸡品种间遗传结构和亲缘关系

以16个中度或高度多态性微卫星标记,运用基于模型分类法的Structure程序推断9个地方鸡品种群体遗传结构,构建聚类图分析相互间亲缘关系,并鉴定群体中迁移个体和具有复杂遗传基础个体的分布。结果表明：Structure程序在预先未标明品种起源的条件下准确推断出9个地方鸡种群体所属类别,揭示按照体型外貌、地理分布等为依据划分的9个地方鸡品种类型,也真实反映了其在遗传上的差异。Structure聚类图在K=2时将9个地方鸡种分为轻体型的鸡种（包括茶花鸡、藏鸡、仙居鸡、固始鸡和白耳鸡）和重体型的鸡种（包括大骨鸡、北京油鸡、鹿苑鸡和萧山鸡）两个类别;K=4、5、6时北京油鸡、固始鸡、大骨鸡分离出来形成独立类群;仙居鸡与白耳鸡在K=6、萧山鸡与鹿苑鸡在K=7、藏鸡与茶花鸡在K=8时仍聚在同一类别中,这与9个地方鸡种的地理分布及形成历史相吻合。9个地方鸡品种群体中均有具有复杂遗传基础的个体分布,迁移个体只分布在藏鸡、萧山鸡和鹿苑鸡群体中。     

酒糟和醋糟营养成分差异及其瘤胃降解特性分析

本试验旨在评价酒糟、醋糟等非常规饲料资源的饲用价值,为酒糟醋糟资源应用于肉牛养殖提供数据参考.试验选用山西不同地区酒糟、醋糟试样5个,试样编号分别为白酒糟、啤酒糟、醋糟1、醋糟2、醋糟3,发酵原料分别为白酒糟(高粱)、啤酒糟(大麦+大米)、醋糟1(高粱+大麦)、醋糟2(大麦+玉米)、醋糟3(高粱+玉米).通过实验室常规...     

Fattening performance and feed source preference of native Awassi lambs fed individually in a cafeteria feeding system

This experiment was conducted to investigate the effect of cafeteria (CF) and conventional (CN) feeding systems on feed intake, feed preferences with respect to voluntary feed source intake, feed conversion rate (FCR) and fattening performance of native Awassi lambs. Sixteen, 3 month old male lambs were used and kept individually for 70 days. Lambs in CF (n = 8) were offered to consume the main ingredients of barley, soybean meal (SBM), sunflower seed meal (SFM) and alfalfa straw, separately, while lambs in CN (n = 8) were fed with a concentrate feed containing 11.34 MJ/kg ME, 17.53% crude protein with the mixture of the same feed sources and alfalfa straw. The initial and final live weights of lambs were similar among groups (P > 0.05). Daily voluntary intake of ash, fat and neutral detergent fiber (NDF) consumptions among groups were quite different during the experiment (P < 0.001). Neither biweekly nor total results of voluntary protein intake between groups were not found statistically significant (P > 0.05). From beginning to the end of the study, the proportional barley intake increased 34 to 43% but reduced for SBM intake from 37 to 23% for the lambs in CF. On the other hand, the SFM intake of lambs did not changed significantly during the experiment and ranged between 2–5%. Lambs in CF did not consume SFM to meet their protein requirement and had 12.5% better total FCR result than the lambs in CN (6.86 and 7.84, respectively) (P > 0.05). The difference of average DWG, total live weight gain, final live weight of lambs in groups were similar (P > 0.05). In conclusion, Awassi lambs in CF can select a diet matching their nutritional requirements from a group of feed sources in response to their growth period when compared to CN system and better FCR result might help to decrease the feed expenses for fattening of native Awassi lambs.     

应用MTT比色法评价不同牛血清促细胞生长作用

细胞培养过程中血清的选择对细胞的促生长增殖具有重要作用。本试验分别以商品新生牛血清、自制新生牛血清、自制成年牛血清培养成纤维细胞、骨髓瘤细胞、杂交瘤细胞,通过MTT比色法来判断细胞的增殖能力,进而对血清质量作出评价。结果表明,自制新生牛血清具有良好的促细胞生长作用(相对生长率＞0.96),并且3次试验结果比较差异不显著(P＞0.05),具有较好的重复性;而成年牛血清和无血清空白对照组促细胞作用不明显。因此应用MTT比色法能够评价血清质量。     

柱花草叶肉原生质体提取与瞬时表达体系构建

柱花草(Stylosanthes guianensis)是一种重要的热区豆科牧草,为利用原生质体瞬时表达体系开展柱花草基因功能研究,以20 d龄期‘热研5号’柱花草子叶为试验材料,通过正交试验考察不同因素对原生质体分离及转化效率的影响。结果表明：采用1.5%纤维素酶、1.25%离析酶、0.5 mol·L^-1甘露醇和4 mmol·L^-1MES酶解液组合,酶解时间为16 h时,原生质体的产量和活性均达到最佳,分别为(4.567×10⁶)个·g^-1和92.271%;原生质体浓度为(6×10⁵)个·mL^-1、质粒浓度为0.6μg·μL^-1,PEG-4000浓度为50%、转化时间为5 min时,转化效率最高,可达52.524%。构建了目标蛋白SgRKL1表达载体pA7-BIUTNT::SgRKL1-GFP,利用PEG介导法将其转入柱花草原生质体,激光扫描共聚焦显微镜检测结果显示SgRKL1蛋白定位于细胞膜上,说明所建立的柱花草叶肉原生质体瞬时表...     

Critical Phase Transition of the Two-dimensional Microcanonical Ising Model by Cellular Automata Q2R Method

The authors construct a microcanonical ensemble system and analyzes the phase change of the two-dimensional Ising model Cellular Automata Q2R/WQ2R method. The result indicates that the numerical value simulation can show the spontaneous magnetization of two-dimensional crystal lattice in isolated system. The authors have observed the critical phase transition phenomenon and gotten the critical energy. The simulation of three-dimensional Ising model can be grounded on the method that this article establishes.     

聚丙烯酰胺凝胶圆盘电泳分离奶牛血清碱性磷酸酶同功酶及鉴定组织来源

用聚丙烯酰胺凝胶圆盘电泳分离黑白花奶牛血清AKP同功酶酶谱及鉴定其组织来源。健康牛血清有5条酶带,以其泳动速率分为快(SF)、慢-1、慢-2、慢-3和慢-4(SS-1～4)。所有血清中除有主带SF和SS-1外,尚有1～3条慢带。骨只有一条泳动速率与血清主带SS-1相同的带,被认为是SS-1的来源。肝有2条泳动较快的带(LF-1和LF-2)和一条慢带LS。其中LF-1为窄的黄带,血清无对应带;LF-2与血清主带SF相对应,为SF的来源;LS为一条与SS-1相对应的浅而宽的带,为血液污染所致。小肠有3条窄的快带(IF-1～3)和一条宽的慢带(IS),慢带与比它稍快的骨带有部分重合出现于部分血清中,而3条快带未在血清出现。各种组织的AKP有不同的热稳定性。总之,血清主带SF和SS-1分别来源于肝和骨,SS-2来源于小肠,SS-3和SS-4在所分析的组织中无相应酶带。本研究较详细地描述了一种被改进的电泳方法,使其易于应用。     

用于滴灌的碟式分离机的转鼓有限元优化设计

碟式分离机的转鼓是一个复杂的锥体,按照传统算法进行其强度计算,得到的结果往往具有很大的质量富余,从而影响到分离机的综合经济指标.为解决这一问题,在有限元应力分析的基础上,以转鼓的总质量为目标函数,以其部分结构参数为优化参数,建立了转鼓的优化设计数学模型.该模型为多维约束优化问题,选取了惩罚函数内点法进行求解,并给出了算法流程图.对实际转鼓的优化结果表明,在保证强度、刚度的前提下,可使分离机的转鼓质量减小24.2%,可提高机械效率,延长转鼓使用寿命.     

双重和三重配种对母猪产仔力影响

本文采用双重和三重配种对本场－千多头母猪的产仔力进行观察结果三重配种显著提高母猪产仔数和产活仔数（Ｐ〈０．０１），两种配种法对仔猪初生重无显著影响（Ｐ〉０．０５）。     

血浆极低密度脂蛋白浓度的双向选择对肉鸡腹脂、肝脂和产肉性能的影响

对零世代８周龄血浆极低密度脂蛋白（ＶＬＤＬ）浓度进行降低腹脂的间接选择，一世代取得了明显效果：腹脂和肝脂向两极分化，其中肌胃脂和肝脂选择反应较大。低血浆ＶＬＤＬ的选择使腹脂降低，肝脂增加，对产肉性状未产生不利影响。９周龄腹脂率、板油率和肌胃脂率在高ＶＬＤＬ系分别高于低ＶＬＤＬ系２１％，１６％和５１％；肌胃脂率品系间差异极显著（Ｐ＜０．００１）。品系与性别互作对肌胃脂率有明显影响（Ｐ＜０．０５）。腹脂、肌胃脂存在性别差异，腹脂率雌性略高于雄性，而肌胃脂率雄性高于雌性。９周龄肝脂率，高ＶＬＤＬ系显著低于低ＶＬＤＬ系（Ｐ＜０．０１），雌性高于雄性。一世代８周龄血浆ＶＬＤＬ产生了直接选择反应，血浆ＶＬＤＬ浓度，高ＶＬＤＬ系高于低ＶＬＤＬ系。血浆ＶＬＤＬ存在性别差异，雄性高于雌性。一世代高、低ＶＬＤＬ系血浆ＶＬＤＬ和腹脂的变异系数仍然很大，继续对其选择仍然有效。由于血浆ＶＬＤＬ属中等遗传力，并且家系间差异显著，因此，在世代选育中应采取家系结合个体选择法