Doublet Anna-Charlotte, Restoux Gwendal, Fritz Sébastien, Balberini Laura, Fayolle Guillaume, Hozé Chris, Laloë Denis, Croiseau Pascal
ALLICE, 149 rue de Bercy, 75012 Paris, France.
Université Paris-Saclay, INRAE, AgroParisTech, GABI, 78350 Jouy-en-Josas, France.
Animals (Basel). 2020 Oct 17;10(10):1903. doi: 10.3390/ani10101903.
In the management of dairy cattle breeds, two recent trends have arisen that pose potential threats to genetic diversity: the use of reproductive technologies (RT) and a reduction in the number of bulls in breeding schemes. The expected outcome of these changes, in terms of both genetic gain and genetic diversity, is not trivial to predict. Here, we simulated 15 breeding schemes similar to those carried out in large French dairy cattle breeds; breeding schemes differed with respect to their dimensions, the intensity of RT use, and the type of RT involved. We found that intensive use of RT resulted in improved genetic gain, but deteriorated genetic diversity. Specifically, a reduction in the interval between generations through the use of ovum pick-up and in vitro fertilization (OPU-IVF) resulted in a large increase in the inbreeding rate both per year and per generation, suggesting that OPU-IVF could have severe adverse effects on genetic diversity. To achieve a given level of genetic gain, the scenarios that best maintained genetic diversity were those with a higher number of sires/bulls and a medium intensity of RT use or those with a higher number of female donors to compensate for the increased intensity of RT.
在奶牛品种管理中，最近出现了两种对遗传多样性构成潜在威胁的趋势：生殖技术（RT）的使用以及育种计划中种公牛数量的减少。就遗传增益和遗传多样性而言，这些变化的预期结果并非轻易就能预测。在此，我们模拟了15种类似于法国大型奶牛品种所实施的育种计划；这些育种计划在规模、生殖技术使用强度以及所涉及的生殖技术类型方面存在差异。我们发现，密集使用生殖技术会带来遗传增益的提高，但会使遗传多样性恶化。具体而言，通过采卵和体外受精（OPU-IVF）缩短世代间隔会导致每年和每代的近亲繁殖率大幅上升，这表明OPU-IVF可能会对遗传多样性产生严重的不利影响。为了达到给定的遗传增益水平，最能维持遗传多样性的方案是那些种公牛数量较多且生殖技术使用强度中等的方案，或者是那些有较多雌性供体以补偿生殖技术使用强度增加的方案。
