SWORD - South West Open Research Deposit - ORBioM (Open Research BioSciences Meeting): Selecting for Less: How Much Methane Can We Truly Breed Away?
 

Presenter Information

Sean B. CrowleyFollow

ORCID

https://orcid.org/my-orcid?orcid=0009-0005-0754-9834

Department

Biological Sciences

Year of Study

2

Full-time or Part-time Study

Full-time

Level

Postgraduate

Presentation Type

Poster

Supervisor

Dr Deirdre Purfield

Supervisor

Dr Noirin McHugh

Supervisor

Prof Donagh Berry

Abstract

Background

Genetic selection has potential to reduce enteric methane emissions from cattle, but a key challenge is determining how much of the genetic variation in methane traits is independent of traits already targeted in breeding programs, such as feed intake and growth.

Methods

Methane and carbon dioxide emissions were recorded in 1,700 crossbred, indoor-fed beef cattle using Greenfeed systems. Performance data included feed intake, metabolic liveweight, average daily gain, carcass weight, and ultrasound and skeletal traits. Genetic parameters and correlations among traits were estimated using animal linear mixed models to quantify the independence of methane-related genetic variation.

Results

Daily methane production was moderately heritable (h² = 0.42), with a genetic standard deviation of 23.43 g/day and a coefficient of genetic variation of 9.26%. However, genetic correlations with feed intake (0.51), growth (0.39), carcass weight (0.48), and metabolic liveweight (0.27) indicated that much of the genetic signal for methane overlaps with performance traits. Genetic adjustment for these traits reduced the genetic standard deviation of methane by 25% to 17.55 g/day, meaning only 56% of the total genetic variance remained independent.

Conclusion

Genetic selection was shown to remain as a viable strategy to reduce methane emissions in growing beef cattle, with substantial genetic variability available for selection even after adjusting for the genetic variability captured in traits most likely to already be under selection in cattle breeding programs.

Keywords:

Methane, Greenhouse gas, beef cattle, genetics, GreenFeed

Start Date

16-6-2025 11:00 AM

End Date

16-6-2025 12:00 PM

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Jun 16th, 11:00 AM Jun 16th, 12:00 PM

Selecting for Less: How Much Methane Can We Truly Breed Away?

Background

Genetic selection has potential to reduce enteric methane emissions from cattle, but a key challenge is determining how much of the genetic variation in methane traits is independent of traits already targeted in breeding programs, such as feed intake and growth.

Methods

Methane and carbon dioxide emissions were recorded in 1,700 crossbred, indoor-fed beef cattle using Greenfeed systems. Performance data included feed intake, metabolic liveweight, average daily gain, carcass weight, and ultrasound and skeletal traits. Genetic parameters and correlations among traits were estimated using animal linear mixed models to quantify the independence of methane-related genetic variation.

Results

Daily methane production was moderately heritable (h² = 0.42), with a genetic standard deviation of 23.43 g/day and a coefficient of genetic variation of 9.26%. However, genetic correlations with feed intake (0.51), growth (0.39), carcass weight (0.48), and metabolic liveweight (0.27) indicated that much of the genetic signal for methane overlaps with performance traits. Genetic adjustment for these traits reduced the genetic standard deviation of methane by 25% to 17.55 g/day, meaning only 56% of the total genetic variance remained independent.

Conclusion

Genetic selection was shown to remain as a viable strategy to reduce methane emissions in growing beef cattle, with substantial genetic variability available for selection even after adjusting for the genetic variability captured in traits most likely to already be under selection in cattle breeding programs.