Antibody prevalence of low-pathogenicity avian influenza and evaluation of management practices in Minnesota backyard poultry flocks

Low‐pathogenicity avian influenza (LPAI) viruses have caused illness in poultry and humans with poultry contact. To determine whether there is evidence of exposure to avian influenza viruses (AIV) among backyard poultry in Minnesota and their human caretakers, 150 flocks of backyard birds were sampled for antibodies to AIV from August 2007 through December 2008. One hundred flocks were tested through routine slaughter surveillance by the Minnesota Board of Animal Health and an additional 50 flocks were contacted and sampled by study investigators. Blood was collected from 10 to 13 birds from each flock and a survey of biosecurity and management practices was administered to the flock owner. Blood samples were tested by agar gel immunodiffusion (AGID) for influenza A antibodies. Tested flocks had a median flock size of 100 birds (range: 12–800 birds), and were most commonly owned for meat for personal use (81% of respondents), fun or hobby (58%) and eggs for personal use (56%). Although 7% of flock owners reported that their birds had shown respiratory signs in the previous 3 months, only 1 of 150 flocks tested positive for influenza by AGID. Antibodies to LPAI H6N1 were detected in the positive flock. The owner of the positive flock did not have antibodies to H6 or other common AIV. Based on the findings of this study, the risk of transmission of LPAI viruses from backyard poultry to owners in Minnesota appears to be low under current conditions and management practices.     

高钙饲粮对青年蛋鸡血清一氧化氮浓度和抗氧化功能的影响

本试验旨在研究高钙饲粮对青年蛋鸡血清一氧化氮（ＮＯ）浓度和抗氧化功能的影响。将 ３５日龄 １００羽伊沙蛋鸡随机均分为对照组（含钙 １．００％）和高钙组（含钙 ３．７８％）,每组 ５个重复,每个重复 １０羽。每天观察鸡的精神状态、食欲和粪便情况。在饲喂高钙饲粮第 ０、８、１６、２４和 ３２天时,分别测定 ２组鸡的血清中 ＮＯ浓度和丙二醛含量及抗氧化酶系统的变化。结果表明：１）高钙饲粮能引起青年蛋鸡长期腹泻,在饲喂高钙饲粮的第 ８天就发生高血钙症。２）与对照组相比,高钙组在饲喂高钙饲粮第 ８天和第 １６天血清 ＮＯ浓度无显著变化（Ｐ＞０．０５）,第２４天和第 ３２天显著升高（Ｐ＜０．０５）;第 ８天和第 ２４天血清超氧化物歧化酶活性、总抗氧化能力无显著变化（Ｐ＞０．０５）,第 １６天显著升高（Ｐ＜０．０５）,第 ３２天显著降低（Ｐ＜０．０５）;第 ８、１６、２４天血清丙二醛含量无显著变化（Ｐ＞０．０５）,第 ３２天显著升高（Ｐ＜０．０５）;第 ２４天和第 ３２天黄嘌呤氧化酶活性有升高趋势（Ｐ＞０．０５）。结果提示,饲喂高钙饲粮可导致青年蛋鸡发生长期腹泻,引起高血钙症,导致其机体内自由基的产生与清除的动态平衡遭到破坏,使自由基的产生远远超出清除能力。     

The effects of continuous and rotational grazing of sourveld on the quality of herbage selected by Simmentaler heifers

A grazing trial was conducted at the Kokstad Agricultural Station to compare the dry matter digestibility (DMD) and crude protein content (CP) of diets selected by four fistulated cattle which were continuously and rotationally grazing sourveld. Two stocking rates of 1,0 and 2,3 animals/ha (0,5 and 1,2 LSU/ha) were applied under each grazing method. The mean DMD and CP values of diets selected in the continuous and rotational grazing treatments, respectively, were: DMD=64,3%, 62,3%; CP=6,63%, 6,88%. The effect of stocking rate on the quality of the diet selected varied between the two grazing methods. DMD and CP of diets selected under rotational grazing decreased with time during the week‐long period of stay in each paddock. On average, DMD and CP values on the first and sixth day respectively, were: DMD=66,6%, 60,5%; CP=8,37%, 6,01%. These differences were more pronounced at the higher than at the lower stocking rate. It was concluded that, although some of the treatment differences were small, grazing method differences in the DMD of diets might at least partially account for observed differences in livemass gains under the two grazing systems.     

The effect of veld condition on the quality of diet selected by cattle grazing the Natal Sour Sandveld

The quality of diet selected by steers fistulated at the oesophagous was related to veld condition in a simulated rotational grazing system on the Natal Sour Sandveld. Six camps, ranging in veld condition score from 8,5 to 53%, were grazed simultaneously for a two‐week period in spring, summer, autumn and winter. Fistula samples were collected on the first, middle and last day of a period of occupation in a camp. Samples were analysed in terms of crude protein (CP), in vitro digestibility (IVD) and plant‐part (% leaf, % stem and % dead material) composition. Dietary quality in terms of CP, IVD and plant‐part composition was not related to veld condition but was dependent largely (P≤0,01) upon season and to a lesser extent upon period of occupation in a camp. It was concluded that in sourveld areas, where dietary quality may be limiting, the veld condition score may be a poor index of potential animal production.     

牛体外受精时老化卵对受精率与染色体异常发生的影响

通过延长体外培养时间得到牛老化卵，对其体外受精率与染色体的异常发生进行了研究，体外受精48h后的受精率，46h培养组与22h和34h培养组之间差异显著（P＜0．05），随着老化时间的延长，受精率及胚胎发育速度明显降低。染色体分析结果表明，46h组的受精卵的染色体异常发生率为61．6％，22h组44．6％，2组之间差异显著（P＜0．05），单倍体（n=31)的发生率也随着老化时间的延长而增加，这些单倍体的性染色体的构成表明，含有X－性染色体的胚的出现率显著高于含有Y－染色体的胚的出现率（P＜0．05）。单倍体的发生是由卵的老化而引起单一配子的孤雌发生，体外培养时间的延长对正常的2倍体的性别无明显影响。     

高温高湿环境对生长猪生长性能、血浆皮质醇浓度和免疫功能的影响

本试验旨在研究高温高湿环境对生长猪生长性能、血浆皮质醇浓度和免疫功能的影响.试验采用2×2双因子完全随机设计,2个温度水平[23和33℃],2个湿度水平(相对湿度为55%和80%).选取体蕈为(30.00±1.72)kg的杜×长×大三元杂交阉公猪24头,随机分为4个处理,每个处理6个重复,每个重复1头猪.试验持续14 d.结果表明:1)环境温度显著影响平均日采食量、平均日增重和料重比(P<0.01),环境湿度显著影响平均日增重和料重比(P<0.01),高温和高湿均使生长性能降低,而温度和湿度的交互作用对生长性能的影响不显著(P>0.05).2)环境温度显著影响第1天(P<0.01)、第7天(P<0.05)血浆皮质醇浓度,高温引起第1天皮质醇浓度升高,第7天降低.环境温度显著影响第7天的白细胞总数(P<0.05),第1天的中性粒细胞数及中性粒细胞/淋巴细胞(N/L)值(P<0.01),第1天、第7天的B淋巴细胞转化率(P<0.05),第14天的CD4+细胞数及CD4+/CD8+值(P<0.05).高温引起第7天的白细胞总数减少,第1天的中性粒细胞数及N/L值升高,第1天、第7天的B淋巴细胞转化率升高,第14天的CD4+细胞数及CD4+/CD8+值降低,湿度以及温度和湿度的交互作用对血浆皮质醇浓度和免疫功能的影响均不显著(P>0.05).结果提示,环境高温、高湿均显著降低猪的生长性能,持续高温能显著降低猪的细胞免疫功能,进而引起抗病力下降.     

中国西部高校师生审美素质调查分析

审美素质是人文素质的重要组成部分,立足中国公民人文素质调查,对中国西部6个省市的387名高校教师和423名大学生的审美素质现状进行了全面的分析,结果表明：（1）西部高校师生的审美素质整体发展良好;（2）西部高校师生的审美素质各要素发展不均衡;（3）西部高校师生在审美意识、审美理想和审美行为3个方面存在显著差异.并且有针对性的提出了4条对策,为西部高校素质教育的改革提供一定的理论参考.     

两种蔗糖浓度对切割取样鼠胚冷冻解冻效果的研究

小鼠晚期桑椹胚、早期囊胚和扩大囊胚，经切割取样分别采用０．３６５Ｍ和０．２５Ｍ蔗糖浓度进一步细管和分步脱除甘油解冻后体外培养发育率分别为６５．５％、４６．４％和７５．４％，两种浓度间差异显著（Ｐ＜０．０５）；分步脱除甘油解冻瑟前者差异不显著（Ｐ＞０．０５），与后者差异极显著（Ｐ＜０．０１）。     

泛素激活酶抑制剂对猪精子获能状态、膜重构及体外受精的影响

【目的】评估泛素激活酶(E1)对猪精子获能、膜重构和体外受精的影响。【方法】选取5头长白猪采集精液,以硫醇酯法评估泛素激活酶(ubiquitin activating enzyme, E1)抑制剂(TAK-243)对精子中泛素(ubiquitin, Ub)与E1结合的影响;将精子分为鲜精组(Fresh)、DMSO组(DMSO)、获能组(Capacitated)及2.4、4.8和7.2 nmol/L TAK-243组,鲜精组用2 mL PBS重悬精子沉淀;获能组用2 mL获能液重悬精子沉淀;DMSO组及2.4、4.8和7.2 nmol/L TAK-243组分别用2 mL含0.07%DMSO及2.4、4.8和7.2 nmol/L TAK-243的获能液重悬精子沉淀,使用微生物动(静)态图像检测系统检测精子的动力学参数;以Western blotting法检测精子的酪氨酸磷酸化水平;Zn²⁺荧光探针检测精子的Zn²⁺含量;花生凝集素染色检测精子的顶体膜重构;免疫荧光法检测顶体表面精子黏附蛋白(AQN-1、AWN)的表达;体外受精法检测TAK-243...     

青海细毛羊断奶羔羊体内钠,钾及血清总脂含量的检测

对湖东种羊场２０只青海细毛羊断奶羔羊体内钠、钾及血清总脂的检测结果表明：血清钠、钾和唾液钠、钾分别为１３５．３０±１４．１７、４．５９±０．８４、１３３．４５±２５．９３、２８．２５±５．１２ｍｍｏｌ／Ｌ,唾液钠、钾比为４．７２∶１,血清总脂４．２４±０．８６ｇ／Ｌ。