国外生猪育种体系简析及对我国生猪育种的几点思考

选择是生猪育种的核心,而准确地选择和选种依赖于完善和成熟的育种体系。国际养猪发达国家(国际育种企业)对育种体系不断完善,长期进行生长、繁殖和肉品质等各类性状的表型测定,运用多场联合评估和基因组选择等方法不断提高遗传评估的准确性,不断挖掘新的育种性状,并进行测定、评估和选育,实现了种猪群体持续的遗传改良和综合性能的不断提升。本文对欧美发达国家(国际育种企业)的生猪育种技术体系进行了综述,以期为我国的生猪育种工作提供参考,并促进我国生猪种业的创新发展。     

44个紫花苜蓿品种的酸铝适应性与耐受性评价

为了解紫花苜蓿在贵州地区的适应性及耐酸铝胁迫机理,以44份紫花苜蓿品种为研究对象,研究紫花苜蓿处于酸铝胁迫下的生理变化,并揭示其生理变化与耐酸铝胁迫间的关系。利用基因与环境互作模型对两个地点1年的紫花苜蓿进行产量分析,筛选出阿尔冈金、新疆大叶苜蓿、Trifecta、Vernal和中牧1号苜蓿5个耐酸铝强适应品种。利用敏感型UC-1465和耐受型阿尔冈金进行酸铝胁迫试验。结果表明：相同处理下,耐受型紫花苜蓿的电导率、相对铝含量、死亡率显著低于敏感型;紫花苜蓿对酸铝胁迫的响应主要通过柠檬酸、苹果酸、乙酸、酒石酸、反丁烯二酸和草酸的显著（P<0.05）增加来体现,其中苹果酸的合成和分泌增多可能是其耐酸铝胁迫的重要原因。     

Review of research methodologies for tigers: Telemetry

Over the past half century, wildlife research has relied on technological advances to gain additional insight into the secretive lives of animals. This revolution started in the 1960s with the development of radio telemetry and continues today with the use of Global Positioning System (GPS)-based research techniques. In the present paper we review the history of radio telemetry from its origins with grizzly bears in Yellowstone to its early applications in tiger research and conservation in Asia. We address the different types of data that are available using radio telemetry as opposed to using other research techniques, such as behavioral observations, camera trapping, DNA analysis and scat analysis. In the late 1990s, the rapid development of GPS collar technology revolutionized wildlife research. This new technology has enabled researchers to dramatically improve their ability to gather data on animal movements and ecology. Despite the ecological and conservation benefits of radio telemetry, there have been few telemetry studies of tigers in the wild, and most have been on the Bengal or Amur subspecies. We close with an assessment of the current tiger conservation efforts using GPS technology and discuss how this new information can help to preserve tigers for future generations.     

我国猪囊虫病的研究概况

囊虫病是一种危害严重的人兽共患病，在我国的发生率较高。近年来，我国学者在该病的流行病学、诊断方法、防制措施以及免疫预防等方面都进行了深入研究，本文就该病的研究进展进行了综述。     

鸡致病性大肠杆菌I型菌毛的研究进展

鸣致病性大肠杆菌I型菌毛是鸡大肠杆菌病的重要致病因子。本文对其生物学特性、在感染中的作用、分子生物学等8个不同方面的研究进展做了综述。     

Genetic evaluation using random regression models with different covariance functions for test‐day milk yield in an admixture population of Thailand goats

The objectives of this study were to compare covariance functions (CF) and estimate the heritability of milk yield from test‐day records among exotic (Saanen, Anglo‐Nubian, Toggenburg and Alpine) and crossbred goats (Thai native and exotic breed), using a random regression model. A total of 1472 records of test‐day milk yield were used, collected from 112 does between 2003 and 2006. CF of the study were Wilmink function, second‐ and third‐order Legendre polynomials, and linear splines 4 knots located at 5, 25, 90 and 155 days in milk (SP25–90) and 5, 35, 95 and 155 of days in milk (SP35–95). Variance components were estimated by restricted maximum likelihood method (REML). Goodness of fit, Akaike information criterion (AIC), percentage of squared bias (PSB), mean square error (MSE), and empirical correlation (RHO) between the observed and predicted values were used to compare models. The results showed that CF had an impact on (co)variance estimation in random regression models (RRM). The RRM with splines 4 knots located at 5, 25, 90 and 155 of days in milk had the lowest AIC, PSB and MSE, and the highest RHO. The heritability estimated throughout lactation obtained with this model ranged from 0.13 to 0.23.     

草业科学专业本科生科研能力培养途径探索

从草业科学专业本科生科研能力现状出发,结合学校实际,对本科生科研能力培养途径进行了探索,阐释了本科生科研能力培养的必要性,分析了本科生科研训练、本科生导师制、科研助理、自选试验探究学习和毕业论文实习对本科生科研能力培养的效果,并就存在问题提出了解决对策。旨在提升本科生科研能力,为培养草业科学专业高素质人才提供保障。     

益生菌安全性和有效性评价方法的研究进展

益生菌是指一类活的、摄入足够量就能够对人体产生有益作用的微生物,目前广泛应用于食品和饲料工业领域。随着市场上商品化益生菌的不断出现,如何评价一个菌株的安全性及有效性成为人们关注的问题。目前,益生菌的评价主要从安全性和有效性入手,安全性和有效性评价又包括体内和体外的评价。很多企业在开发益生菌产品时很少对菌株做出全面的安全性评价,而且各国研究者采用的评价指标和评价方法也不尽相同。对于有效性评价,同样也没有统一的评价标准。针对目前益生菌评价存在的问题,亟需建立一套完善的评价方法,对益生菌的安全性和有效性进行系统、科学地评价。作者从益生菌可能产生的潜在危害及功效方面出发,着重论述了益生菌的溶血性、毒力因子、抗生素抗性和产有毒代谢产物的体外安全性评价方法,耐酸、耐胆盐、耐人工胃肠液、胃肠黏膜黏附性和抑菌活性的体外有效性评价方法,及体内的安全性和有效性评价方法的研究进展,期望为建立完善的益生菌评价技术体系和标准提供参考。     

垂穗披碱草落粒性评价及农艺性状的相关性分析

为挖掘优异垂穗披碱草(Elymus nutans)种质资源,加快其抗落粒品种选育,本研究在前期资源筛选基础上,于2015-2016年对13份垂穗披碱草种质的落粒性及15个农艺性状进行了变异、相关性、主成分和聚类分析,并用隶属函数法对农艺性状进行了综合评价。结果表明,15个农艺性状中落粒率的变异系数最大,为57.43%,穗长的变异系数最小,为5.77%。13份种质中,PI619516落粒率最低,种柄断裂拉伸张力(breaking tensile strength,BTS)测定值达70.05gf,种质PI639855的落粒率最高,BTS值为13.99gf。BTS变异分析表明,种质PI639852的变异系数最大,为45.09%,表明该种质在落粒性方面存在较大的种内遗传差异。相关性分析表明,倒二叶长与旗叶长和旗叶宽,旗叶长与旗叶宽呈极显著正相关(P0.01),每穗小花数与穗长和茎粗呈显著正相关(P0.05),BTS与穗长和茎粗呈显著负相关(P0.05),表明穗长和茎粗越大,BTS就越小,落粒率就越高。以BTS值为变量的聚类分析结果表明,13份种质被聚为4类,第ⅰ类种质落粒性最高,第ⅱ和第ⅲ类种质表现出很高的落粒性,而第ⅳ类种质落粒性中等。15个农艺性状的综合聚类分析结果表明,13份种质被聚为4类。隶属函数分析表明,种质PI547394的综合性状表现优异,综合隶属函数值为0.55。本研究为垂穗披碱草育种提供了宝贵的遗传资源。     

甘肃高山细毛羊妊娠母羊营养需要量估测

借助其他品种绵羊营养需要的一些研究方法,结合甘肃高山细毛羊四季牧草干物质采食量、营养物质摄入量、采食牧草营养成分、牧草营养物质消化率以及生产相关数据,采用析因法估测甘肃高山细毛羊能量和蛋白质需要量:成年母羊维持代谢能需要量为6.58 MJ/d(每kg代谢体重维持代谢能需要为0.417 MJ/W^0.75),维持蛋白质需要量107.62 g/d;妊娠前期代谢能需要量为12.54 MJ/d,粗蛋白质需要量125.19 g/d;妊娠后期代谢能需要量为12.86 MJ/d,粗蛋白质需要量为146 g/d;通过对比研究表明,甘肃高山细毛羊成年母羊钙需要量约为8.22~9.61 g/d,磷需要量为4.98~5.87 g/d,食盐需要量为9~16 g/d。