Animal Genetics Division, Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute, Bareilly, 243122, India.
ICAR National Professorial Chair, Centre of Advanced Faculty Training in Animal Nutrition, Indian Veterinary Research Institute, Izatnagar, 243122, India.
Mol Biol Rep. 2022 Aug;49(8):8153-8161. doi: 10.1007/s11033-022-07718-1. Epub 2022 Jul 1.
In livestock sector, dairy animals alone produce 18% of the total greenhouse gas emissions globally as methane (CH). This Enteric methane is the largest component of total carbon footprints produced by livestock production system and its reduction is today's new challenge to make livestock farming sustainable for earth's environment. The production of enteric methane in ruminants is a complex phenomena involving different host factors like host genotype, rumen microbiome, host physiology along with dietary factors. Efforts have been made to reduce methane emissions largely through nutritional interventions and dietary supplements, but permanent reductions can be obtained through genetic means by selecting and breeding of low methane emitting animals. From genome-wide association studies, many important genomic QTL regions and single nucleotide polymorphisms involved in shaping the composition of the ruminal microbiome and thus their carbon footprints have been recognised, implying that methane emission traits are quantitative traits. The major bottleneck in implementation of reduced methane emission traits in the breeding programs is wide variation at phenotypic level, lack of precise methane measurements at individual level. Overall, the heritability for CH production traits is moderate, and it can be used in breeding programmes to target changes in microbial composition to reduce CH emission in the dairy industry for far-reaching environmental benefits at the cost of a minor reduction in genetic gain in production traits.
在畜牧业中，仅奶牛就产生了全球温室气体排放总量的 18%，其中甲烷（CH）占比 18%。这种肠道甲烷是畜牧业生产系统产生的总碳足迹的最大组成部分，因此减少肠道甲烷排放是当前使畜牧业可持续发展以应对地球环境的新挑战。反刍动物肠道甲烷的产生是一个复杂的现象，涉及到宿主基因型、瘤胃微生物组、宿主生理学以及饮食因素等不同的宿主因素。人们已经做出了很大的努力来减少甲烷排放，主要通过营养干预和饮食补充，但可以通过选择和培育低甲烷排放动物的遗传手段来获得永久性的减少。从全基因组关联研究中，已经识别出许多涉及塑造瘤胃微生物组组成及其碳足迹的重要基因组 QTL 区域和单核苷酸多态性，这意味着甲烷排放性状是数量性状。在将减少甲烷排放性状应用于育种计划中的主要瓶颈是表型水平的广泛变异，以及个体水平缺乏精确的甲烷测量。总的来说，CH 生产性状的遗传力中等，可以在育种计划中利用，以改变微生物组成，从而减少乳制品行业的 CH 排放，从而获得深远的环境效益，而生产性状的遗传增益略有减少。
