Timothy P. Bilton, Setegn W. Alemu, Ken G. Dodds, Hannah Henry, Melanie K. Hess, Ronan Jordan, Fern Booker, Sharon M. Hickey, Neville Amyes, Kevin Knowler, Edgar Sandoval, Jacqueline Peers-Adams, Tracey C. van Stijn, Hayley Baird, Trevor Watson, Wendy Bain, Barry Veenvliet, Gerard Pile, Brooke Bryson, Shannon M. Clarke, Patricia L. Johnson, John C. McEwan, Suzanne J. Rowe
{"title":"Rumen metagenome profiles are heritable and rank the New Zealand national sheep flock for enteric methane emissions","authors":"Timothy P. Bilton, Setegn W. Alemu, Ken G. Dodds, Hannah Henry, Melanie K. Hess, Ronan Jordan, Fern Booker, Sharon M. Hickey, Neville Amyes, Kevin Knowler, Edgar Sandoval, Jacqueline Peers-Adams, Tracey C. van Stijn, Hayley Baird, Trevor Watson, Wendy Bain, Barry Veenvliet, Gerard Pile, Brooke Bryson, Shannon M. Clarke, Patricia L. Johnson, John C. McEwan, Suzanne J. Rowe","doi":"10.1186/s12711-025-00973-3","DOIUrl":null,"url":null,"abstract":"Global targets to reduce greenhouse gas emissions to meet international climate change commitments have driven the livestock industry to develop solutions to reduce methane emission in ruminants while maintaining production. Research has shown that selective breeding for low methane emitting ruminants using genomic selection is one viable solution to meet methane targets at a national level. However, this requires obtaining sufficient measures of methane on individual animals across the national herd. In sheep, one affordable method for measuring methane on-farm to rank animals on their methane emissions is portable accumulation chambers (PAC), although this method is not without its challenges. An alternative is to use a proxy trait that is genetically correlated with PAC methane measures. One such trait that has shown promise is rumen metagenome community (RMC) profiles. In this study, we investigate the potential of using RMC profiles as a proxy trait for methane emissions from PAC using a large sheep dataset consisting of 4585 mixed-sex lambs from several flocks and years across New Zealand. RMC profiles were generated from rumen samples collected on the animals immediately after being measured through PAC using restriction enzyme-reduced representation sequencing. We predicted methane (CH4) and carbon dioxide (CO2) emissions (grams per day), as well as the ratio CH4/(CO2 + CH4) (CH4Ratio), from the RMC profiles and SNP-array genotype data. Heritability and microbiability estimates were similar to values found in the literature for all traits. The correlation of PAC methane with predicted methane was 1.9- to 2.3-fold (CH4) and 1.2- to 1.5-fold (CH4Ratio) greater for RMC profiles compared to host genomics only. The genetic correlation between methane predicted from RMC profiles and PAC methane was 0.75 ± 0.12 for CH4 and 0.64 ± 0.11 for CH4Ratio when using a validation set consisting of the animals with the most recent year of birth in the dataset. RMC profiles are predictive of, and genetically correlated, with PAC methane measures. Therefore, RMC profiles are a suitable proxy trait for determining the genetic merit of an animal’s methane emissions and could be incorporated into existing breeding programs to facilitate selective breeding for low methane emitting sheep.","PeriodicalId":55120,"journal":{"name":"Genetics Selection Evolution","volume":"16 1","pages":""},"PeriodicalIF":3.1000,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Genetics Selection Evolution","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1186/s12711-025-00973-3","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRICULTURE, DAIRY & ANIMAL SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
Global targets to reduce greenhouse gas emissions to meet international climate change commitments have driven the livestock industry to develop solutions to reduce methane emission in ruminants while maintaining production. Research has shown that selective breeding for low methane emitting ruminants using genomic selection is one viable solution to meet methane targets at a national level. However, this requires obtaining sufficient measures of methane on individual animals across the national herd. In sheep, one affordable method for measuring methane on-farm to rank animals on their methane emissions is portable accumulation chambers (PAC), although this method is not without its challenges. An alternative is to use a proxy trait that is genetically correlated with PAC methane measures. One such trait that has shown promise is rumen metagenome community (RMC) profiles. In this study, we investigate the potential of using RMC profiles as a proxy trait for methane emissions from PAC using a large sheep dataset consisting of 4585 mixed-sex lambs from several flocks and years across New Zealand. RMC profiles were generated from rumen samples collected on the animals immediately after being measured through PAC using restriction enzyme-reduced representation sequencing. We predicted methane (CH4) and carbon dioxide (CO2) emissions (grams per day), as well as the ratio CH4/(CO2 + CH4) (CH4Ratio), from the RMC profiles and SNP-array genotype data. Heritability and microbiability estimates were similar to values found in the literature for all traits. The correlation of PAC methane with predicted methane was 1.9- to 2.3-fold (CH4) and 1.2- to 1.5-fold (CH4Ratio) greater for RMC profiles compared to host genomics only. The genetic correlation between methane predicted from RMC profiles and PAC methane was 0.75 ± 0.12 for CH4 and 0.64 ± 0.11 for CH4Ratio when using a validation set consisting of the animals with the most recent year of birth in the dataset. RMC profiles are predictive of, and genetically correlated, with PAC methane measures. Therefore, RMC profiles are a suitable proxy trait for determining the genetic merit of an animal’s methane emissions and could be incorporated into existing breeding programs to facilitate selective breeding for low methane emitting sheep.
期刊介绍:
Genetics Selection Evolution invites basic, applied and methodological content that will aid the current understanding and the utilization of genetic variability in domestic animal species. Although the focus is on domestic animal species, research on other species is invited if it contributes to the understanding of the use of genetic variability in domestic animals. Genetics Selection Evolution publishes results from all levels of study, from the gene to the quantitative trait, from the individual to the population, the breed or the species. Contributions concerning both the biological approach, from molecular genetics to quantitative genetics, as well as the mathematical approach, from population genetics to statistics, are welcome. Specific areas of interest include but are not limited to: gene and QTL identification, mapping and characterization, analysis of new phenotypes, high-throughput SNP data analysis, functional genomics, cytogenetics, genetic diversity of populations and breeds, genetic evaluation, applied and experimental selection, genomic selection, selection efficiency, and statistical methodology for the genetic analysis of phenotypes with quantitative and mixed inheritance.