Meuwissen T H
DLO-Institute of Animal Science and Health, Lelystad, The Netherlands.
J Anim Sci. 1997 Apr;75(4):934-40. doi: 10.2527/1997.754934x.
A method was derived that maximizes the genetic level of selected animals while constraining their average coancestry to a predefined value. The average coancestry of the selected parents equals the inbreeding level in the next generation, so that rates of inbreeding were controlled. When this method was applied for several generations of selection, stable rates of genetic gain were attained, which indicates that the method could control the short- and long-term effects of selection on inbreeding. At equal rates of inbreeding, genetic gains were 21 to 60% greater than that with selection for BLUP-EBV, because of increased selection differentials. The difference was larger when the desirable rate of inbreeding was smallest. Selection with a constraint on inbreeding required only EBV of, and relationships between, the selection candidates and is therefore easy to apply in practice. The optimal solution is expressed in genetic contributions of selection candidates to the next generation, which is equivalent to numbers of offspring per candidate. These optimal numbers of offspring may be difficult to attain because of female reproductive limitations. The optimal method could be adapted to situations with additional reproductive constraints. The method can also be used to constrain the variance of response by restricting the average prediction error variance of the selected animals.
推导了一种方法，该方法在将所选动物的平均亲缘系数限制在预定义值的同时，使所选动物的遗传水平最大化。所选亲本的平均亲缘系数等于下一代的近亲繁殖水平，从而控制了近亲繁殖率。当将此方法应用于几代选择时，获得了稳定的遗传增益率，这表明该方法可以控制选择对近亲繁殖的短期和长期影响。在相同的近亲繁殖率下，由于选择差异增加，遗传增益比基于最佳线性无偏预测估计育种值（BLUP-EBV）的选择高21%至60%。当理想的近亲繁殖率最小时，差异更大。对近亲繁殖进行约束的选择仅需要选择候选个体的估计育种值及其之间的亲缘关系，因此在实践中易于应用。最优解以选择候选个体对下一代的遗传贡献来表示，这等同于每个候选个体的后代数量。由于雌性繁殖限制，这些最优后代数量可能难以实现。最优方法可以适用于具有额外繁殖限制的情况。该方法还可用于通过限制所选动物的平均预测误差方差来约束反应方差。
