Comparison of sow farrowing characteristics between a Chinese breed and three French breeds

Sow farrowing characteristics, including litter size, stillbirth, kinetics of births and piglet weight traits, were compared in 4 populations: Meishan (MS), Large White (LW), Duroc × Large White (DU × LW) and Laconie (LA). The kinetics of births was characterised by farrowing duration (FD), birth interval (BI), and farrowing irregularity, estimated by the standard deviation of BI (SDBI). The within-litter distribution of piglet birth weights was described by different traits including the mean (MBW) and standard deviation (SDBW) of birth weight. Additional characteristics of the sow were also analysed: weight at farrowing (SWF), gestation length (GEST), and birth assistance (BA). The data set included 47 MS, 605 LW, 55 DU × LW and 160 LA litters. For analyses, multivariate methods were used, including principal component analyses (PCA) and multiple factorial analyses (MFA). These methods allowed the relative importance of between-breed and within-breed variability of the correlation structure to be estimated and the homogeneity between populations (by comparison of the 4 breed correlation structures) to be investigated. Though most of the variability was observed within-breed (97%), between-breed variation appeared to be highly significant (P < 0.0001). This variation was essentially due to the Meishan breed departing from others, because of the lower weight at farrowing and, to a lesser extent, to the lower number of stillbirths and lower piglet mean and standard deviation in birth weight. Litter size did not contribute much to the variability between breeds. The rather strong correlations related to between-breed structures (r > 0.70) indicated that the correlation pattern was similar among breeds. Stillbirth was independent from litter size and appeared as closely associated with farrowing duration in the French breeds.     

中国家养动物品种资源浅析

中国家养动物种按驯养时期早晚分，早期驯养的就有２２个物种，除猫狗外，现有６５０余个品种，是中国畜牧业可持续发展的基础。晚期驯养的有１４个物种，地中国畜牧业可持续发展亦是不可缺少的。在占品种总数的７７％的地方品种中，有少数品受受到威胁，已有１０个品种灭绝，８个品种濒临灭绝，２０个品种数量减少。     

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小麦是宁夏的主要粮食作物之一,随着耕地面积减少、人口增加,提高小麦单产势在必行;宁春4号自在生产上大面积应用以来,迄今也有近30a的历史,但仍没有更好的品种出现来实现宁夏春小麦的第5次更新;而引进的以蓝粒作为标记性状分离、保持不育系的新型蓝粒二系法杂交小麦系统,是一套切实可行的杂交小麦系统。     

晋南牛的开发利用方向

本文论述了开发利用晋南牛资源的方法、具体措施，并对晋南牛选育与开发利用上存在的问题给予说明，提出了建议，最后阐述了对晋南牛实施保种的途径，并展望了晋南牛今后的发展方向。     

搞好晋南牛选育保种,促进商品化生产发展

本文首先介绍了晋南牛在运城地区的发展现状。接着对搞好晋南牛选育保种所做的具体工作作了阐述，对晋南牛杂交改良效果作了总结；对运城地区规模养牛的现状给予了积极评价；最后提出了今后对晋南牛实施综合开放利用做的具体工作。     

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本文阐述了建立晋南牛基因库的重要意义，指出在晋南牛基因库的组成成份及其作用。同时就建立基因库阐述了保种原则和指标，最后提出了建立晋南牛基因库要做的几项具体工作。     

郏县红牛育种模式探讨

本文在总结郏县红牛２０年保种选育经验基础上，根据市场发展趋势及生物技术水平，提出了建立活体保种冷精胚胎保种相结合珠保种体系的技术措施，重点探讨了通过引入外血提高郏县红牛早熟性，泌乳性，肉用性的育种技术模式。