Animal Breeding and Genomics, Wageningen University & Research, 6700 AH Wageningen, the Netherlands.
Animal Breeding and Genomics, Wageningen University & Research, 6700 AH Wageningen, the Netherlands.
Animal. 2021 Dec;15 Suppl 1:100294. doi: 10.1016/j.animal.2021.100294. Epub 2021 Jul 8.
The global livestock sector, particularly ruminants, contributes substantially to the total anthropogenic greenhouse gases. Management and dietary solutions to reduce enteric methane (CH) emissions are extensively researched. Animal breeding that exploits natural variation in CH emissions is an additional mitigation solution that is cost-effective, permanent, and cumulative. We quantified the effect of including CH production in the Dutch breeding goal using selection index theory. The current Dutch national index contains 15 traits, related to milk yield, longevity, health, fertility, conformation and feed efficiency. From the literature, we obtained a heritability of 0.21 for enteric CH production, and genetic correlations of 0.4 with milk lactose, protein, fat and DM intake. Correlations between enteric CH production and other traits in the breeding goal were set to zero. When including CH production in the current breeding goal with a zero economic value, CH production increases each year by 1.5 g/d as a correlated response. When extrapolating this, the average daily CH production of 392 g/d in 2018 will increase to 442 g/d in 2050 (+13%). However, expressing the CH production as CH intensity in the same period shows a reduction of 13%. By putting economic weight on CH production in the breeding goal, selective breeding can reduce the CH intensity even by 24% in 2050. This shows that breeding is a valuable contribution to the whole set of mitigation strategies that could be applied in order to achieve the goals for 2050 set by the EU. If the decision is made to implement animal breeding strategies to reduce enteric CH production, and to achieve the expected breeding impact, there needs to be a sufficient reliability of prediction. The only way to achieve that is to have enough animals phenotyped and genotyped. The power calculations offer insights into the difficulties that will be faced in trying to record enough data. Recording CH data on 100 farms (with on average 150 cows each) for at least 2 years is required to achieve the desired reliability of 0.40 for the genomic prediction.
全球畜牧业，特别是反刍动物，对人为温室气体排放总量有重大影响。人们广泛研究管理和饮食方面的解决方案，以减少肠道甲烷（CH）排放。利用 CH 排放的自然变异进行动物育种是另一种具有成本效益、永久性和累积性的缓解方案。我们使用选择指数理论来量化在荷兰育种目标中包含 CH 生产的效果。当前的荷兰国家指数包含 15 个与牛奶产量、寿命、健康、繁殖力、体型和饲料效率相关的性状。从文献中，我们获得了肠道 CH 生产的遗传力为 0.21，与牛奶乳糖、蛋白质、脂肪和 DM 摄入量的遗传相关性为 0.4。肠道 CH 生产与育种目标中其他性状之间的相关性设定为零。当在当前的育种目标中包含 CH 生产且其经济价值为零时，CH 生产每年以 1.5g/d 的相关反应增加。以此类推，2018 年 392g/d 的平均每日 CH 产量将增加到 2050 年的 442g/d（增加 13%）。然而，在同一时期将 CH 产量表示为 CH 强度，则表明减少了 13%。通过在育种目标中给 CH 生产赋予经济权重，选择育种甚至可以在 2050 年减少 24%的 CH 强度。这表明，育种是实现欧盟 2050 年目标所应用的整套缓解策略的一项有价值的贡献。如果决定实施减少肠道 CH 生产的动物育种策略并实现预期的育种效果，就需要具有足够的预测可靠性。实现这一目标的唯一方法是对足够多的动物进行表型和基因型分析。功效计算提供了对试图记录足够数据所面临的困难的深入了解。为了达到 0.40 的基因组预测可靠性，需要在至少 2 年内对 100 个农场（每个农场平均有 150 头奶牛）记录 CH 数据。
