两种运输车对驴运输应激的影响

本试验旨在研究改造运输车对缓解驴运输应激的效果。选取28头健康德州公驴,随机分为2组,从北京密云县运输至聊城市东阿县东阿黑毛驴研究所,路程约500 km,历时18 h。试验使用9.6 m长单层货车为运输车,对试验组(T)运输车进行改造,即加装顶层和双侧篷布、底部加装草帘和中部加装隔栏,对照组(C)不作处理。运输前后测定驴血液生化和激素指标,统计体重变化和发病驴数量。结果表明,与运输前相比,普通车组驴在落地当天检测到血清皮质醇(COR)、白蛋白(ALB)水平均显著升高(P<0.05),总蛋白(TP)、谷草转氨酶(AST)、热休克蛋白-90(HSP90)和肌酸激酶(CK)指标极显著升高(P<0.01),钙(Ca)浓度显著降低(P<0.05)。改造车组驴血液指标TP、AST和CK的变化范围低于普通车组。两组驴落地后血糖(GLU)水平均比运输前升高,但差异均不显著(P<0.05)。与运输前相比,改造车组驴落地后的体重减少低于普通车组;改造车组驴在落地后第10天平均体重接近运输前,而普通车组驴的平均体重在落地后第20天才基本恢复至运输前水平,即使用改造运输车辆可以尽早恢复体重。普通车组驴发病率为21.4%,改造车组为7.1%;两组均无死亡。综合上述结果,改造运输车可有效降低驴的运输应激,有利于提高动物运输福利,减少经济损失;本试验结果可为动物运输应激提供参考。     

哈萨克羊iNOS基因多态性与布鲁氏菌病的相关性分析

试验旨在探讨哈萨克羊诱导型一氧化氮合酶（iNOS）基因多态性与布鲁氏菌病的相关性。使用虎红平板凝集试验（RBPT）方法对231只哈萨克羊血清进行布鲁氏菌病血清学检测,参考GenBank中绵羊iNOS基因序列,针对其第6、7、8外显子及其邻近内含子片段设计引物,利用PCR-SSCP技术和DNA测序技术对231只哈萨克羊的iNOS基因进行多态性检测,分析其SNPs与哈萨克羊布鲁氏菌病易感性的相关性。结果表明,67只哈萨克羊为布鲁氏菌感染阳性,阳性检出率为29.00%。在哈萨克羊iNOS基因的外显子6和8片段上未检测到多态位点,在外显子7片段上检测出F7-T18054C和F7-C18084T 2个多态位点,在F7-T18054C多态位点上检测到3种基因型（TC、TT、CC）,优势等位基因和基因型分别是C型和CT型,其等位基因频率和基因型频率分别是0.660和0.446。在F7-C18084T多态位点上检测到2种基因型（CT、CC）,优势等位基因频率和基因型分别是C和CC型,其等位基因和基因型频率分别是0.946和0.892。F7-C18084T属于低度多态（PIC<0.25）,F7-T18054C属于中度多态（0.25 < PIC < 0.5）。相关性分析表明,F7-T18054C和F7-C18084T多态位点与布鲁氏菌病易感性无显著相关性（P>0.05）。试验结果表明,哈萨克羊iNOS基因F7-T18054C和F7-C18084T多态位点与布鲁氏菌病易感性不存在相关性。     

木薯渣发酵饲料及其发酵工艺与应用

文章旨在研究木薯渣发酵饲料及其发酵工艺与应用。将木薯渣、玉米面、豆粕、玉米皮、麸皮按照质量比50∶5∶10∶10∶25的比例混合,然后将乳酸菌和酵母菌按比例与一定量的水混合,再与木薯渣饲料混匀,装入带有呼吸阀的发酵袋中,密封,室温条件下发酵4 d即生产得到木薯渣发酵饲料。结果表明：乳酸菌和酵母菌混合比例为1∶2,接种量为0.1%,水分为40%～45%时,木薯渣发酵饲料pH<4.5,酸溶蛋白和总酸含量明显增加,具有明显的酸香气味,可提高适口性;可抑制霉菌生长,确保产品安全性;还可提高饲料的营养水平和猪只消化率,提高饲料利用率;提高猪只生产性能,降低圈舍氨气浓度,改善舍内环境;同时还为木薯渣资源化利用提供良好的前提条件。     

规模化猪场非洲猪瘟防控

非洲猪瘟疫情已经成为制约养猪业发展的头号杀手,生猪稳产保供任务引起高度重视,因此,防控非洲猪瘟疫情是各级政府和养猪企业的重点工作之一,该文主要论述规模化猪场非洲猪瘟防控措施。     

基于ARM的育苗架智能监控系统设计

为了解决当前育苗过程中环境参数控制不便等问题,提出一种新的基于嵌入式ARM平台的育苗架智能监控系统。该系统搭载嵌入式Linux操作系统,采用Pt100温度传感器和NWSF-1AT湿度传感器,以及加热、加湿装置,可以对育苗架内的环境参数进行实时监测和智能控制。系统采用Modbus通信协议和RS-485数据接口,利用Qt开发用户界面,同时包含数据库功能,能够自动记录历史数据,便于后续的数据分析。大量实验表明,本系统可以实时监测育苗架内温湿度变化,当设定期望温度为25℃、湿度为40%RH时,能够有效地将育苗架内的温湿度环境稳定在设定值,能够为催芽育苗工作提供所良好的内部环境。     

电压空间矢量脉宽调制的简单算法

在电压空间矢量脉宽调制(SVPWM)控制技术原理的基础上,提出了一种简单快速算法,该算法只有普通的四则运算,计算变得非常简单,消除了常规的空间矢量控制算法中由于三角函数和无理数的近似计算而带来的计算误差及影响计算精度和速度的缺点,使结果更加准确。因而更适合应用于基于DSP 的数字化控制。理论分析和大量的MATLAB仿真结果表明,该算法具有谐波含量低、直流电压利用率高的优点。     

信息技术用于汽车纵梁制造的探讨

文章以为汽车行业的健康发展提供指导和借鉴为目的,主要对汽车的纵梁平面图纸集成化制造中诸如参数提取、纵梁3D模型构建技术和Agent的网络集成技术的应用方法等进行了相关论述,以此为实现汽车行业的可持续发展而做出贡献。     

Effects of dietary supplementation of emulsifier and carbohydrase on the growth performance,serum cholesterol and breast meat fatty acids profile of broiler chickens

A total of 540 2‐day‐old male Ross 308 broilers were used in a 35‐day experiment and were randomly divided into five treatments: (i) NC (low energy); (ii) PC (high energy diet); (iii) P1 (NC + 0.1% carbohydrases); (iv) P2 (NC + 0.05% emulsifier); and (v) P3 (NC + 0.1% carbohydrases + 0.05% emulsifier). From days 0 to 21, body weight gain in PC and P3 treatments increased (P < 0.05) compared with NC treatment. The chicks fed PC, P1, P2 and P3 improved (P < 0.05) feed conversion ratio compared with the NC treatment throughout the whole experiment. Abdominal fat weight was heavier (P < 0.05) in PC, P2 and P3 treatments than in NC and P1 treatments. On day 35, serum total cholesterol and low density lipoprotein cholesterol concentration were higher (P < 0.05) and high‐density lipoprotein cholesterol was lower (P < 0.05) in NC and P2 treatments than in PC, P1 and P3 treatments. The concentration of oleic acid, linoleic acid and total unsaturated fatty acids were highest (P < 0.05) in PC than in the other treatments. In conclusion, the results indicate that low energy density diet had lower growth performance, while the inclusion of emulsifier and carbohydrases in low energy diets can partially improve growth performance.     

Canine fetal echocardiography: correlations for the analysis of cardiac dimensions

The aim of this study was to develop regression models for correlation of canine fetal heart development with body size to characterize normal development or suggest cardiac anomalies. Twenty clinically healthy pregnant bitches, either brachycephalic and non-brachycephalic, were examined ultrasonographically. Transabdominal fetal echocardiography was conducted every 4 days from the beginning of cardiac chambers differentiation until parturition. Ten cardiac parameters were measured: length, width and diameter of the heart; heart area; left and right ventricular dimensions; left and right atrial dimensions; and aortic and pulmonary artery diameter. Femoral length, biparietal diameter and abdominal cross-sectional area were also recorded. Regression equations were developed for each parameter of fetal body size, and linear and logarithmic models were compared. The model with the highest correlation coefficient was chosen to produce equations to calculate relative dimensions based on the correlations. Only the left-ventricular chamber differed between the two racial groups. Biparietal diameter was the independent parameter that produced the highest correlation coefficient for the most fetal cardiac dimensions, although good correlations were also observed using femoral length and abdominal cross-sectional area. Heart width and heart diameter were used as surrogates of cardiac development, as these measurements showed the best statistical correlation. Quantitative evaluation of fetal cardiac structures can be used to monitor normal and abnormal cardiac development.     

Tenogenic induction of equine mesenchymal stem cells by means of growth factors and low-level laser technology

Tendons regenerate poorly due to a dense extracellular matrix and low cellularity. Cellular therapies aim to improve tendon repair using mesenchymal stem cells and tenocytes; however, a current limitation is the low proliferative potential of tenocytes in cases of severe trauma. The purpose of this study was to develop a method useful in veterinary medicine to improve the differentiation of Peripheral Blood equine mesenchymal stem cells (PB-MSCs) into tenocytes. PB-MSCs were used to study the effects of the addition of some growth factors (GFs) as TGFβ3 (transforming growth factor), EGF2 (Epidermal growth factor), bFGF2 (Fibroblast growth factor) and IGF-1 (insulin-like growth factor) in presence or without Low Level Laser Technology (LLLT) on the mRNA expression levels of genes important in the tenogenic induction as Early Growth Response Protein-1 (EGR1), Tenascin (TNC) and Decorin (DCN). The singular addition of GFs did not show any influence on the mRNA expression of tenogenic genes whereas the specific combinations that arrested cell proliferation in favour of differentiation were the following: bFGF2 + TGFβ3 and bFGF2 + TGFβ3 + LLLT. Indeed, the supplement of bFGF2 and TGFβ3 significantly upregulated the expression of Early Growth Response Protein-1 and Decorin, while the use of LLLT induced a significant increase of Tenascin C levels. In conclusion, the present study might furnish significant suggestions for developing an efficient approach for tenocyte induction since the external administration of bFGF2 and TGFβ3, along with LLLT, influences the differentiation of PB-MSCs towards the tenogenic fate.