从历史上看,奶牛的繁殖主要集中在数量相对较少的精英公牛上。近年来,即使减少了世代间隔,可以选择更多不同的儿子,基因组选择并没有从根本上改变大量个体被分析的事实。然而,相对较少的精英公牛仍在吸引这些动物。因此,基因库中近亲繁殖衍生的负面后果引起了人们的关注。由于乳制品生产与生殖性状之间的拮抗关系,近交抑郁和优势等非加性遗传变化的有害影响已广泛传播,同时严重影响了生物经济上重要的参数。因此,近亲繁殖的益处和局限性的估计和选择响应的方差值得评估和讨论,以保持遗传变异,在选择个体进行繁殖和生产时的一个重要问题。通过现代育种计划改善遗传价值的短期策略严重降低了高产奶牛的繁殖力潜力。由于当前的选择计划可能会增加长期成本,因此,全球遗传多样性下降。因此,在管理农场盈利能力时,应优先考虑选择计划对支持奶牛种群长期遗传可持续性和遗传多样性的潜力。本综述为当前近亲繁殖衍生的问题提供了广泛的方法,确定需要解决的关键点和可能的替代策略,以控制纯合单倍型的选择,同时保持持续的选择压力。此外,这份手稿探讨了未来的前景,强调理论应用和临界点,和策略,以避免奶牛近亲繁殖的不利影响。最后,这篇综述概述了即将需要多学科方法来管理奶牛种群的挑战,打算将生产性状表型的增加与生殖的改善相结合,健康,福利,线性构象,和可预见的未来的适应性特征。
Dairy cattle breeding has historically focused on relatively small numbers of elite bulls as sires of sons. In recent years, even if generation intervals were reduced and more diverse sires of sons could have been selected, genomic selection has not fundamentally changed the fact that a large number of individuals are being analyzed. However, a relatively small number of elite bulls are still siring those animals. Therefore inbreeding-derived negative consequences in the gene pool have brought concern. The detrimental effects of non-additive genetic changes such as inbreeding depression and dominance have been widely disseminated while seriously affecting bioeconomically important parameters because of an antagonistic relationship between dairy production and reproductive traits. Therefore, the estimation of benefits and limitations of inbreeding and variance of the selection response deserves to be evaluated and discussed to preserve genetic variability, a significant concern in the selection of individuals for reproduction and production. Short-term strategies for genetic merit improvement through modern breeding programs have severely lowered high-producing dairy cattle fertility potential. Since the current selection programs potentially increase long-term costs, genetic diversity has decreased globally as a consequence. Therefore, a greater understanding of the potential that selection programs have for supporting long-term genetic sustainability and genetic diversity among dairy cattle populations should be prioritized in managing farm profitability. The present
review provides a broad approach to current inbreeding-derived problems, identifying critical points to be solved and possible alternative strategies to control selection against homozygous haplotypes while maintaining sustained selection pressure. Moreover, this manuscript explores future perspectives, emphasizing theoretical applications and critical points, and strategies to avoid the adverse effects of inbreeding in dairy cattle. Finally, this
review provides an overview of challenges that will soon require multidisciplinary approaches to managing dairy cattle populations, intending to combine increases in productive trait phenotypes with improvements in reproductive, health, welfare, linear conformation, and adaptability traits into the foreseeable future.