保种与选育有机结合是解决我国丰富的畜禽品种遗传资源保存的一个重要的有效手段。本文探讨在保种目标性状明确的情况下，如何利用通用选择指数灵活方便地制定选择标准，以达到保种与选育相结合的目的。并以良种细毛羊的选育为例，确定了在保证羊毛质量不下降的基础上，充分利用各种信息来源评定个体的综合育种值，达到尽量提高羊毛产量的目的。此外，探讨了在保种目标的约束下主攻净毛量等，以及当保种性状也需改进时的选择方法，为保种与选育相结合探索一条可行的途径。

从达尔文到现代动物育种理论基础。即群体遗传学和数量遗传学的建立。历时近一个世纪。其主线之一是围绕达尔文进化论的争论，到以Haldane。Fishcr和wright的群体遗传学为理论基础的新达尔文主义形成，其二是以Batcson为代表的孟德尔遗传学派与以Pearson和wcldon为首的统计遗传学派，围绕数量性状遗传基础长迭十数年之久的争论，到Lush的动物育种理论建立，本文试图对这一过程作一综合探讨。

The F2 design was used in construction of the pig resource population, and 14 economic important traits of 119 F2 offspring were measured. The polymorphisms of heart fatty acid binding protein gene (H-FABP) were detected by PCR-RFLP. The effects of different H-FABP genotypes were analyzed by a fixed model. The results showed that, the carcass composition traits were affected by H-FABP gene significantly, backfat thickness alive, carcass backfat thickness between 6th-7th rib, and average carcass backfat thickness, of different H-FABP genotypes were significantly different (P<0.05). The dominant effects on the traits demonstrated that the gene affected the carcass composition traits overdominantly. The results also showed that H-FABP gene affected the growth traits and meat quality traits, and the pH, of different H-FABP genotypes was significantly different.

Pig breeding is generally conducted among many herds, so EBV comparisons across populations are necessary. Genetic connectedness is required for reliable between-farm animal EBV comparisons. Five quantitative overall connectedness measures among populations have been proposed so far, coefficient of connectedness(γ*), coefficient of determination (CD) and overall indices of precision, connectedness rating, number of direct genetic links between subpopulations due to common sires and dams (GLt), and average genetic covariance (AGC) are reviewed and their properties are discussed in this paper. It is recommended to use AGC at present for measuring genetic connectedness between herds.