Effects of Large Saddle Panels on the Biomechanics of the Equine Back During Rising Trot: Preliminary Results

The saddle panels, directly in contact with the horse's back, are likely an important element to optimize the fitting of the saddle, the comfort of the horse, and subsequently, the pain management in dorsalgic horses. The aim of this study was to better understand the effect of the saddle panels on the horse's back, by evaluating a prototype saddle (comfort panels: CP) compared to a standard saddle (STD). The horse's back movements were measured using inertial measurement units (IMUs) fixed at the levels of thoracic vertebrae T6, T12, T16 (under the saddle) and lumbar vertebrae L2 and L5. The centers of mass (COMs) of the horse and the rider and limb's protraction-retraction angles, pressure between saddle and horse's back, and force on the stirrups were measured using respectively 2D motion capture, pressure mat and force sensors in the stirrup leather. Three horses were trotted at the rising trot (sitting: left diagonal-rider seated; standing: right diagonal-rider standing) by the same rider. To compare saddles, linear mixed-effects regression models were used. The estimated means (SE) were calculated. During sitting phase, pressure in the cranial and middle areas of the saddle significantly increased for CP compared to STD (+0.9 (0.2) kPa and +1.0 (0.1) kPa, respectively) whereas caudal pressure decreased (−1.8 (0.4) kPa). Concurrently, the range of motion of angles T12-T16 and T16-L2 under the saddle significantly increased (+1.8 (0.2)° and +2.3 (0.3)°, respectively). The results showed that modifications of the panels' shape not only affect the pressure distribution but also the kinematics of the thoracic and lumbar regions of the equine back.     

基于模糊建模的混炼胶粘度测量

提出了一种在线测量混炼胶粘度的新方法．该方法以模糊建模技术为基础，综合考虑混炼过程各因素对胶料粘度的影响，建立起胶料粘度的在线测量模型．在模糊建模中，采用T-S模型描述胶料粘度变化的非线性过程，提出了一种基于相似性判别的模糊聚类算法以自动确定合适的聚类组数目，并用实数编码的遗传算法优化全局参数，从而获得了规则简化的、具有较高精度的模糊模型．根据此方法，设计了测量装置，并进行了现场试验．试验结果表明模糊模型输出与实验室测量值基本一致，平均误差较低且最大误差未超过1门尼．该方法较大地提高了橡胶混炼的生产效率，为粘度最优控制奠定了基础．     

分离群体中常染色体上标记基因的数量遗传方差——Ⅰ.含有一个数量性状位点(QTL)时的计算方法

应用常染色体上的标记基因研究能够加快数量性状的遗传进展。亲代由标记基因遗传给后代的加性遗传方差值可以用来测定标记基因这种效益。分别在个体水平上以及在复合连续平衡的分离群体水平上建立了标记基因加性遗传方差值的理论方程。这些方程包括与标记基因连锁的数量性状位点数、这些数量性状位点的效应值以及与标记基因有关的重组率。并就分离群体中标记基因加性遗传方差的期望值进行了推导。在分离群体的系谱选择方案中,常染色体上遗传方差中绝大部分与位于该染色体上的标记基因相关。对于牛的一个平均长度染色体来讲,这部分值大约是该染色体孟德尔分离方差值的40% 。标记基因的位置效应和干扰因素对这一期望值的影响是很小的,而染色体的长度对期望方差值影响很大。如果标记基因缺乏多态型以及染色体替代效应估计偏差会大大降低MAS的选择效果。常染色体上标记基因遗传方差期望值的大小表明:即使当标记基因处在一个非活动位点,在分离群体中,仍有较大的染色体替代效应存在。     

步进电机扭矩测量试验台系统的设计

专用电机扭矩测量仪器精度高，但价格昂贵，操作复杂，长时间使用会出现误差。步进电机扭矩测量试验台系统采用单相交流电机作负载，使用标准扭矩仪对该系统进行标定来对待测调速电机进行扭矩测量。为此，介绍了一种电机扭矩测量系统的构成与工作原理。该系统以单片机为核心，组成扭矩测量与显示系统，可以较好地实现电机扭矩在线测量，具有较好的经济效益。     

微波电路电测及其计算方法

从实际工程的角度出发，对电路电测方法进行了论述。在微通信工程中，需要获得障碍物的位置和高度，最合理的天线高度组合和障碍物绕射损耗等参数，为此论述了微波电路电测方法及技术要求。在大庆－秦皇岛输油管道通信工程中采用了Ａ，Ｂ测试法进行测试，得到高度－损耗曲线。这种曲线给出相对自由空间接收电平与收，发天线高度之间的关系。在测试所得的高度－损耗曲线与断面图相结合的基础上，由绕射损耗计算公式推出了几种常见障碍     

散养成乳牛舍环境测定

以一栋散养成乳牛舍为对象，系统地测定了舍内外的气温、气湿、风速、辐射强度、黑体温度及屋顶热流量。结果表明：从６月１日—９月１０日，舍内旬均气温都在２３．４３℃以上，舍内１４：００气温旬均值都在２８℃以上，舍内旬均ＴＨＩ都超过７１．７１；屋顶热流量曲线的斜率很大、峰值出现于１４：００，并且与舍外黑体温度呈高度的正相关；舍内与舍外的黑体温度、辐射强度分别呈中等以上的正相关；冬季舍内寒冷，同时受舍外气流影响大。笔者认为，通过增加牛舍高度、先用高热阻屋面材料和冬季防风可望改进此类牛舍的环境。     

家兔选育性状典型相关分析

选择日本大耳白和新西兰两个品种家兔的生长、繁殖、以及体尺3组共17个性状，应用多元统计方法进行了典型相关分析，结果表明；日本大耳白兔的初生重、初生窝重、21日龄重、泌乳力、胸围等5个性状，新西兰兔的产活仔数、初生重、21日龄重、泌乳力、断奶窝重、母兔体重等6个性状为主要性状。     

Molecular genetics of behaviour: research strategies and perspectives for animal production

Genetic factors are undoubtedly involved in inter-individual variability of the behaviours that may be important for livestock production, as shown by pedigree studies, comparison of genetic stocks raised in the same environment, and selection experiments. The knowledge of gene polymorphisms responsible for genetic variability would increase the efficiency of selection, as shown for instance by the identification of the ryanodine receptor gene that harbours the mutations responsible for the porcine stress syndrome, that allows the eradication of the susceptibility allele. One strategy is to screen systematically the genes that are known to be involved in regulation of behaviour (functional candidate genes). This strategy is however very difficult for most behavioural traits, since behaviour is an emerging function from the whole brain/body and the molecular pathways involved in genetic variability are very poorly understood. Another strategy is to investigate linkage between trait variation and genetic markers in a segregating population (usually an intercross or backcross between two strains or breeds contrasting for the trait under study). It allows the detection of genomic regions influencing that trait (quantitative trait loci or QTL), and further investigation aims at the identification of the gene(s) located in each of these regions and the molecular polymorphisms involved in phenotypic variation. Although many QTL have been published for behavioural traits in experimental animals, very few examples are available where strong candidate genes have been identified. Further progress will be very much dependent upon the careful definition of behavioural traits to be studied (including their importance for animal production), on the reliability of their measurement in a large number of animals and on the efficient mastering of environmental factors of variability. The fast increase in the knowledge of genome sequence in several species will undoubtedly facilitate the application to farm animal species of the knowledge obtained in model organisms, as well as the use of model organisms to explore candidate genes detected by QTL studies in farm animals.     

青脚鸡杂交组合肉用性能的研究

以江苏省家禽科学研究所家禽育种中心崇仁麻鸡♂×(崇仁麻鸡♂×隐性白羽鸡新品系♀)♀(配套1)和固始鸡♂×(崇仁麻鸡♂×隐性白羽鸡新品系♀)♀(配套2)为素材,进行肉用性能试验,结果表明①两配套组合体重差异极显著(P＜0.01),配套2比配套1重109.6克且饲料报酬高0.171;②两配套组合龙骨长、冠长、冠高、胸宽差异不显著(P＞0.05),体斜长、胫长、胫围、胸角差异极显著(P＜0.01),配套2均高于配套1.③两配套组合屠体率、半净膛率、全净膛率、胸肌率、腹脂率差异不显著(P＞0.05),配套1腿肌率显著高于配套2(P＜0.05).④两配套组合胸肌失水率、PH值、肉色、剪切力差异不显著(P＞0.05).总体而言,配套2的肉用性能优于配套1,隐性白羽鸡新品系在优质鸡配套系中应用是可行的.     

体尺细分法在竞赛用伊犁马选择上的应用研究

本文采用体尺细分法 ,测定了乌鲁木齐马术俱乐部 2 4匹伊犁马 1 9个细分体尺及 1 0 0 0m速度成绩。分析细分体尺与速度的相关性 ,结果为 :颈长、肩长、肱骨长、股骨长、胫骨长、肩倾角、股骨倾角、髋骨倾角与速度呈显著 (P <0 0 5)或极显著 (P <0 0 1 )相关