浅谈营养调控对仔猪生长发育的影响

<正>仔猪阶段是猪只一生生长发育的基础,也是其一生中最脆弱,经历应激最多、最强烈的时期。因为此时其自身的免疫系统、体温调节机能、消化系统和微生态系统均尚未完善,同时又面临着出生、剪牙、断尾、去势、断奶、转群、免疫注射、营养改变、环境不适等众多应激,极易引发各种疾病。要搞好仔猪的培育,需要同时做好环境控制、饲养管理、疾病防治、营养调控等多方面的工作。根据仔猪不同时期的生理特点,营养需求,充分做好营养调控,从内因着手提高     

猪繁殖与呼吸综合征病毒E蛋白在Marc-145细胞中的表达

针对PRRSV E基因设计1对带有EcoRⅠ和SalⅠ酶切位点的引物,以PRRSV CC-1株为模版进行RT-PCR扩增,获得带有酶切位点的目的片段插入pMD18-T载体,对阳性重组质粒进行测序鉴定。将阳性质粒进行EcoRⅠ、SalⅠ双酶切,回收目的片段将其插入EcoRⅠ、SalⅠ双酶切的真核表达载体pEGFP-N1中构建重组质粒pEGFP-N1-E,将重组质粒用脂质体转染Marc-145细胞,通过荧光显微镜观察显示,在转染后24h出现荧光,48h出现荧光高峰,筛选阳性细胞株,进行目的基因转录、Western blot检测目的蛋白的表达鉴定。结果表明:成功构建真核表达载体pEGFP-N1-E,建立了稳定表达的细胞株。为研究E蛋白如何与宿主细胞结合形成通道,PRRSV吸附、穿入宿主细胞的作用机理以及筛选特效的粒子通道阻断剂奠定了基础。     

大学文化与思想政治教育的融合创新探析

大学文化是一所大学生存、发展、传承的精神根基,是学校办学特色和综合实力的体现。本文阐述了大学文化与思想政治教育的基本含义及其创新,探讨了思想政治教育文化场域的建构与发展,丰富了对大学文化与思想政治教育的融合创新的认识,推动了和谐校园的建设和大学文化与思想政治教育的融合创新。     

提高仔猪成活率和断奶体重的技术措施

1新生仔猪的特点 新生仔猪生长发育快和生理上的不成熟,导致易病难养,增重慢,死亡率高,其主要特点： 1.1生长发育快,物质代谢旺盛 仔猪出生重一般为1.2kg左右,不到成年猪体重的1%,但生长发育迅速,10日龄体重可达出生时的2~3倍,30日龄达5~6倍。仔猪的强烈生长,是以旺盛的物质代谢为基础,20日龄的仔猪,每千克体重需沉积蛋白质9~14g,相当于成年猪的30多倍,每千克体重所需代谢净能为成年猪的3倍左右,矿物质代谢也高于成年猪。可见,仔猪对营养物质的需要,在数量和质量上都相当高,对营养不全极为敏感。     

我国科学家破解了畜禽骨加工的世界性难题

正7月17日,由中国农业科学院农产品加工研究所主持、山东悦一生物科技有限公司等6家单位共同完成的"骨素加工关键技术装备研发与应用"成果通过了农业部组织的科技成果鉴定,专家组一致认为,该项目在骨素热压高效抽提、真空梯度膜浓缩偶联等方面实现了技术突破与创新,在原料骨前处理、骨素热压抽提、骨素衍生化加工关键装备研制等方面实现了自主创新,整体技术水平达到了国际领先水平。据农产品加工研究所张春晖研究员介绍,可食性动物骨中含有11%~16%的优质蛋白,约为     

饲料行业未来发展趋势

正冯定远教授认为由于饲料原料的缺乏是短期内无法解决的,所以使用越来越多的非常规的饲料原料是大势所趋。考略到成本、供给、来源等,在未来玉米、豆粕、鱼粉等比较传统的容易消化的饲料原料的使用会减少。但是大家都知道现在的饲料配比中玉米占60%以上,豆粕的使用量也不少,怎么寻找替代物呢?冯教授告诉记者:通过类同作用,可以寻找一些能量性的物质替代玉米,比如木薯、小麦,稻谷等,豆粕可以使用一些非常规的蛋白类如菜籽粕、棉籽粕、羽毛粉、皮革粉甚至一些食品原料的下脚料来替代,但是在替     

中国科学家领衔“破译”绵羊基因组

正新华社华盛顿6月5日电(记者林小春)由中国科学家领衔的一个国际科研小组5日宣布,历经5年时间,他们完成了对绵羊基因组的测序、组装及分析工作。这项成果使人们对反刍动物生物学有了崭新认识。更重要的是,中国是绵羊和山羊饲养及羊肉消费大国,新研究将促进选育出更优秀的肉羊新品种。绵羊基因组的测序工作在2009年正式启动,其中中国科学院昆明动物研究所与华大基因联合测序一头母羊,而英国罗斯林研究所测序一     

罗非鱼的人工口腔哺育法

罗非鱼类以其味美、生长快、繁殖力强及能以摄食浮游植物饵料而转化为动物蛋白源等优点。在世界各地得到普遍推广养殖．特别是尼罗罗非鱼，在日本企业化养殖也已获取成功，现在年产量可达3500吨。     

Fiber effects in nutrition and gut health in pigs

Dietary fiber is associated with impaired nutrient utilization and reduced net energy values. However, fiber has to be included in the diet to maintain normal physiological functions in the digestive tract. Moreover, the negative impact of dietary fiber will be determined by the fiber properties and may differ considerably between fiber sources. Various techniques can be applied to enhance nutritional value and utilization of available feed resources. In addition, the extent of fiber utilization is affected by the age of the pig and the pig breed. The use of potential prebiotic effects of dietary fiber is an attractive way to stimulate gut health and thereby minimize the use of anti-microbial growth promoters. Inclusion of soluble non-starch polysaccharides （NSP） in the diet can stimulate the growth of commensal gut microbes, inclusion of NSP from chicory results in changes in gut micro-environment and gut morphology of pigs, while growth performance remains unaffected and digestibility was only marginally reduced. The fermentation products and pH in digesta responded to diet type and were correlated with shifts in the microbiota. Interestingly, fiber intake will have an impact on the expression of intestinal epithelial heat-shock proteins in the pig. Heat-shock proteins have an important physiological role in the gut and carry out crucial housekeeping functions in order to maintain the mucosal barrier integrity. Thus, there are increasing evidence showing that fiber can have prebiotic effects in pigs due to interactions with the gut micro-environment and the gut associated immune system.     

Dairy sheep production research at the University of Wisconsin-Madison,USA-a review

Commercial milking of sheep is a new agricultural industry in the United States starting approximately 30 yr ago. The industry is still small, but it is growing. The majority of the sheep milk is used in the production of specialty cheeses. The United States is the major importer of sheep milk cheeses with 50 to 60% of annual world exports coming to the United States during the past 20 yr. Therefore, there is considerable growth potential for the industry in the United States. The only dairy sheep research flock in North America is located at the Spooner Agricultural Research Station of the University of Wisconsin-Madison. The research program started in 1993 and has been multifaceted; dealing with several areas important to commercial dairy sheep farmers. The East Friesian and Lacaune dairy breeds were compared and introduced to the industry through the research program. Both dairy breeds produced significantly more milk than traditional meat-wool breeds found in the U.S., but the two breeds differed in their production traits. East Friesian-cross ewes produced more lambs and slightly more milk than Lacaune-cross ewes whereas Lacaune-cross ewes produced milk with a higher percentage of fat and protein than East Friesian-cross ewes. Lactation physiology studies have shown that ewes with active corpora lutea have increased milk yields, oxytocin release during milking is required to obtain normal fat percentages in the milk, large udder cisterns of dairy ewes can allow for increased milking intervals, and short daylengths during late pregnancy results in increased milk yield. In the nutrition area, legume-grass pastures and forages with a higher percentage of legume will result in increased milk production. Grazing ewes respond to additional supplementation with increased milk yield, but it is important to match the supplement to the quality of the grazing. Ewes on high quality legume-grass pastures that are high in rumen degradable protein respond with increased milk production to supplements high in energy and/or