Methyl donors dietary supplementation to gestating sows diet improves the growth rate of offspring and is associating with changes in expression and DNA methylation of insulin‐like growth factor‐1 gene

The study aimed to investigate the effects of maternal dietary methyl donors on the performance of sows and their offspring, and the associated hepatic insulin‐like growth factor‐1 (IGF‐1) expression of the offspring. A total of 24 multiparous sows were randomly fed the control (CON) or the CON diet supplemented with methyl donors (MD) at 3 g/kg betaine, 15 mg/kg folic acid, 400 mg/kg choline and 150 μg/kg VB₁₂, from mating until delivery. After farrowing, sows were fed a common lactation diet through a 28‐days lactation period and six litters per treatment were selected to be fed until at approximately 110 kg BW. Maternal MD supplementation resulted in greater birthweight (p < 0.05) and increased the piglet weights (p < 0.01) and litter weights (p < 0.05) at the age of day 28, compared with that in CON group. The offspring pigs in the MD group had greater ADG (p < 0.05) and tended to lower F:G ratio (p = 0.07) compared with that of CON group from day 28 to 180 of age. The offspring pigs from MD group had greater serum IGF‐1 concentrations and expressions of hepatic IGF‐1 gene and muscular IGF‐1 receptor (IGF‐1r) protein at birth (p < 0.05), and greater hepatic IGF‐1 protein (p = 0.03) and muscular IGF‐1r gene expressions (p < 0.05) at slaughter, than that from the CON group. Moreover, the methylation at the promoter of IGF‐1 gene in the liver of newborn piglets and finishing pigs was greater in the MD group than that of the CON group (p < 0.05). In conclusion, maternal MD supplementation throughout gestation could enhance the birthweight and postnatal growth rate of offspring, associated with an increased expression of the IGF‐1 gene and IGF‐1r, as well as the altered DNA methylation of IGF‐1 gene promotor.     

陕西省榆林市某鸡场家禽H7N9流感紧急流行病学调查

2017年5月21日,陕西省榆林市某养殖场的蛋鸡出现异常死亡。经国家参考实验室确诊,该起疫情为H7N9流感疫情。为找出引发疫情的可能原因,采用描述性流行病学方法,描述疫情的三间分布,分析发病的风险因素。调查结果显示:该场饲养规模较大,共有8栋鸡舍,饲养4.5万只蛋鸡;疫情暴发突然,病程仅为5 d;蛋鸡死亡2.2万只,死亡率为48.9%;疫情具有明显的场内传播规律,从靠近鸡场入口的鸡舍逐渐向内蔓延;产蛋高峰期蛋鸡的发病风险是雏鸡的37.458倍,差异显著(P0.05);所分离毒株的HA基因裂解位点有4个氨基酸插入,为变异株;该起疫情可能是通过运输淘汰蛋鸡的车辆、野鸟、饲料和饮水,以及调入雏鸡等途径引入的。疫情发生后,当地政府按照《高致病性禽流感防治技术规范》,发布了封锁令,划定了疫点、疫区和受威胁区;在疫区采取了扑杀、无害化处理、关闭疫区内所有禽类产品交易市场等控制措施。采取以上处置措施后,疫情得以快速有效控制。     

新疆阿勒泰垦区规模化羊群弓形虫病血清流行病学调查

为摸清新疆阿勒泰垦区兵团第十师北屯市规模化羊群的弓形虫感染情况,采用间接血凝试验(IHA),对采集自第十师所属7个团场的890份羊血清进行了弓形虫血清抗体检测。结果显示:该地区规模化羊群的弓形虫血清抗体平均阳性率为6.18%(55/890);不同羊群均有感染,表明感染分布广泛;母羊群感染率较高,为9.36%;羊群感染率随羊年龄增加而升高。这些情况需引起足够重视。     

Determination and Analysis of Heavy Metal Content in the Soil from Beef Cattle Farms in Three Regions of Xinjiang

In order to study and evaluate the feeding environment of the beef cattle farms in Xinjiang, the contents of heavy mentals in the soil from 8 beef cattle farms in Xinjiang Aksu, Yili and Tacheng regions were tested according to the Field of Livestock and Poultry Environment Quality Standard (NY/T 388—1999).The atomic absorption spectroscopic method was used to determine the contents of As, Hg, Pb, Cd, and Cr.The mean contents of As, Hg, Pb, Cd, and Cr in 8 beef cattle farms soil were 0.389, 0.568, 22.708, 0.573 and 149.449 mg/kg, respectively, and they were all below the upper limit of NY/T 388—1999.The comprehensive heavy metal pollution index of 8 beef cattle farms were 0.577 to 0.994, and the index were 0.7 to 1 of two observation points in Yili and one observation point in Tacheng.The soil environment quality of these 3 farms were at the level of slight cleaning.The comprehensive heavy metal pollution index of other five observation points were ≤0.7, the soil environment was in a clean level.The soil environment of beef cattle farms in these three regions conformed to the standards of livestock for environment quality and safe products.     

我国木门自动化制造特点及发展趋势

木门加工装备的自动化水平直接影响木门的生产效率和产品质量,并决定企业的竞争力.笔者依据国内木门自动化制造领域丰富的实践经验,对我国木门自动化制造的特点及未来发展趋势进行了分析,为木门生产企业加工装备升级提出建议.     

微细木质粉尘静电除尘器的设计

近年来,随着人们对环境质量的要求逐渐提高,木材工业除尘日益得到重视。众所周知,木材工业是产生粉尘的大户,如不采取有效的除尘措施,产生的粉尘不但会造成极大的环境污染,而且还会对工人的身体健康、产品质量、设备的精度和使用年限及生产的安全造成危害。目前,在木材工业中,广泛采用的多是离心力除     

聚脲喷枪混合室的设计和FLUENT仿真分析

为提高聚脲喷涂喷枪的混合效果，基于撞击流理论设计了一种新型聚脲喷涂喷枪的混合室。混合室采用两级撞击混合，分别采用两组T型和两组Y型对撞混合形式。利用SolidWorks设计混合室的结构模型后，利用FLUENT软件，采用冷、热水在混合室内撞击混合、对流传热的方法进行仿真模拟，并且计算了流体在混合室内的微观混合时间。结果表明:合理增加撞击流混合室的混合级数和采用多组T型、Y型对撞混合形式可增益混合效果；撞击流混合室的主要混合区是在撞击区；流体在喷枪内停留的总时间约为5.71 ms，满足具有反应迅速这一特性的材料的混合要求；微观混合时间小于1 ms，混合效果优异。      

白藜芦醇和褪黑素对绵羊胎儿成纤维细胞转染及卵母细胞体外成熟的影响

试验旨在利用白藜芦醇(Re)和褪黑素(MT)提高绵羊胎儿成纤维细胞电穿孔转染(电转)效率、优化卵母细胞体外成熟体系,以提高转基因动物生产效率。将绵羊胎儿成纤维细胞分为6组:对照组、添加白藜芦醇高、中、低(R^-5、R^-6、R^-7)3种浓度组及白藜芦醇和褪黑素联合添加组(R^-5M^-5、R^-6M^-7),通过电转效率和细胞凋亡情况确定电转体系优化方案;通过对细胞周期、线粒体膜电位及活性氧(ROS)的检测研究其作用机制。将绵羊卵母细胞分为对照组及白藜芦醇和褪黑素(R^-5M^-5、R^-6M^-7)联合添加组,通过绵羊卵母细胞体外成熟后卵丘细胞扩展、第一极体排出及体外受精胚胎的卵裂率检测其对卵母细胞体外成熟的作用。研究结果显示,分离的绵羊胎儿成纤维细胞P3代增殖旺盛,细胞生长曲线呈典型的S型;与对照组相比,所有试验组胎儿成纤维细胞的电转效率均显著提高(P<0.05),R^-5M^-5组电转效率最高;R^-6M^-7组显著降低细胞凋亡率(P<0.05),R^-5、R^-6、R^-5M^-5和R^-6M^-7组均显著促进细胞增殖(P<0.05);R^-6、R^-7、R^-5M^-5和R^-6M^-7组G1期细胞增加,S期细胞相对减少,但差异均不显著(P>0.05);R^-6、R^-7、R^-5M^-5和R^-6M^-7组成纤维细胞内ROS水平均显著降低(P<0.05),R^-6、R^-5M^-5和R^-6M^-7组线粒体膜电位均显著增加(P<0.05);R^-6M^-7组显著促进绵羊卵丘细胞扩展、提高卵母细胞第一极体排出率和体外受精胚胎发育能力(P<0.05)。综上,白藜芦醇和褪黑素可以优化绵羊胎儿成纤维细胞电转体系,提高卵母细胞体外成熟效率,为白藜芦醇和褪黑素在转基因动物生产中的应用提供参考依据。     

温室自动牵引车设计与应用

自动导航牵引车在工业中担任运输物料的作用，随着单栋温室的面积不断增大，操作区之间的距离逐渐增大，为了实现各操作区之间的联系，高效完成运输、采摘和喷洒等各项任务，开发一种应用于温室中的自动导航牵引车。该设备主要包括驱动总成、转向总成、AGV控制总成、手动控制总成、路面清理装置、铅酸蓄电池、底盘和外壳。开发的温室自动牵引车不仅能够实现自动导航，在面积巨大、路况复杂或线路不确定的区域还能够实现手动控制。在温室生产中应用灵活方便，极大地提高了现代农业的装备化水平。      

罹患口腔炎乌苏里蝮的相关生理学指标分析

口腔炎是人工养殖蛇类的常见病之一,为了深入了解和尽早做好预防工作,对罹患口腔炎的成年雄蛇乌苏里蝮(Gloydius ussuriensis)进行解剖观察,并检测了相关器官的系数、血液学指标和激素等。结果表明:整体肥满度、躯体肥满度、肾系数等数值罹患口腔炎蛇略高于健康蛇;而肝系数、精巢系数和脂肪体系数等罹患口腔炎的蛇低于健康雄蛇,且前两者呈显著性差异,后者呈极显著性差异。性激素检测结果显示罹患口腔炎的蛇血液睾酮和雌二醇含量均低于健康蛇,且均具极显著性差异。血细胞指标中,红细胞数量、红细胞分布均差、白细胞总数、淋巴细胞数量和淋巴细胞比率等均为罹患口腔炎的蛇高于健康雄蛇,且具显著性差异,但嗜中性粒细胞和淋巴细胞的比值(NLR)、中性粒细胞数量和比率、中间细胞数量及其比率均为患口腔炎的雄蛇低于健康蛇,且具显著性差异。结论:口腔炎不仅影响了主要代谢器官的器官系数的变化,而且血液多项指标和性激素水平也有明显差异。性激素含量的变化将对乌苏里蝮的正常生殖繁育产生不可忽视的影响。另外,NLR和红细胞分布宽度2个血常规指标可作为早期诊断炎症发生的首选参数。