Genetics and genomics of reproductive performance in dairy and beef cattle
Genetics and genomics of reproductive performance in dairy and beef cattle
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DOI：
10.1017/s1751731114000743
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发表时间：
2014-05-01
期刊：
影响因子：
3.6
通讯作者：
Pryce, J. E.
中科院分区：
文献类型：
--
作者：
Berry, D. P.;Wall, E.;Pryce, J. E.
雄性和雌性的良好繁殖性能是有利可图的乳制品和牛肉生产系统的基础。在这篇综述中，我们对55项乳制品研究或人群、12项牛肉研究或人群以及28项不同的男性生殖性能研究或人群中女性生殖性能的遗传参数进行了荟萃分析。奶牛和肉牛中存在过多的生殖表型，对文献的荟萃分析表明，奶牛和肉牛中的大多数雌性生殖性状倾向于低遗传性（0.02至0.04）。雄性动物的生殖相关表型（例如精液质量）往往比雌性动物的生殖表型更具遗传性，精液相关性状的平均遗传力估计值在0.05至0.22之间，但阴囊周长（0.42）和田间不返率（0.001）除外。然而，繁殖性状的遗传力低，特别是在女性中，并不意味着遗传选择不能改变表型性能，直到最近，奶牛繁殖性能的下降部分归因于积极的选择，以增加牛奶产量。此外，繁殖性状与产奶量（奶牛）和产肉量（肉牛）之间的拮抗性遗传相关并不一致，这意味着同时进行遗传选择以提高产奶量和产肉量以及繁殖性能确实是可能的。育种目标中对生殖性状的要求以阻止恶化将根据基本假设而有所不同，并使用爱尔兰、英国和澳大利亚的例子以及量化对牛奶产量遗传增益的影响进行了讨论。基因组技术的进步可以帮助提高选择的准确性，特别是生殖性状，从而遗传增益。阐明生殖的潜在基因组机制也有助于解决遗传拮抗作用。过去的育种计划导致奶牛和肉牛的繁殖性能下降。然而，现在存在的工具可以逆转所观察到的表型趋势背后的生殖性能的遗传趋势。
Excellent reproductive performance in both males and females is fundamental to profitable dairy and beef production systems. In this review we undertook a meta-analysis of genetic parameters for female reproductive performance across 55 dairy studies or populations and 12 beef studies or populations as well as across 28 different studies or populations for male reproductive performance. A plethora of reproductive phenotypes exist in dairy and beef cattle and a meta-analysis of the literature suggests that most of the female reproductive traits in dairy and beef cattle tend to be lowly heritable (0.02 to 0.04). Reproductive-related phenotypes in male animals (e.g. semen quality) tend to be more heritable than female reproductive phenotypes with mean heritability estimates of between 0.05 and 0.22 for semen-related traits with the exception of scrotal circumference (0.42) and field non-return rate (0.001). The low heritability of reproductive traits, in females in particular, does not however imply that genetic selection cannot alter phenotypic performance as evidenced by the decline until recently in dairy cow reproductive performance attributable in part to aggressive selection for increased milk production. Moreover, the antagonistic genetic correlations among reproductive traits and both milk (dairy cattle) and meat (beef cattle) yield is not unity thereby implying that simultaneous genetic selection for both increased (milk and meat) yield and reproductive performance is indeed possible. The required emphasis on reproductive traits within a breeding goal to halt deterioration will vary based on the underlying assumptions and is discussed using examples for Ireland, the United Kingdom and Australia as well as quantifying the impact on genetic gain for milk production. Advancements in genomic technologies can aid in increasing the accuracy of selection for especially reproductive traits and thus genetic gain. Elucidation of the underlying genomic mechanisms for reproduction could also aid in resolving genetic antagonisms. Past breeding programmes have contributed to the deterioration in reproductive performance of dairy and beef cattle. The tools now exist, however, to reverse the genetic trends in reproductive performance underlying the observed phenotypic trends.