Selective breeding as a mitigation tool for methane emissions from dairy cattle.

Area of Science:

• Animal Science
• Agricultural Science
• Environmental Science

Background:

• Global livestock, especially ruminants, significantly contribute to anthropogenic greenhouse gas emissions.
• Reducing enteric methane (CH4) emissions is crucial for environmental sustainability.
• Animal breeding offers a cost-effective, permanent, and cumulative strategy for methane mitigation.

Purpose of the Study:

• To quantify the impact of incorporating methane production into the Dutch breeding goal.
• To evaluate the effectiveness of selective breeding for reducing methane intensity in livestock.
• To determine data requirements for reliable genomic prediction of methane production.

Main Methods:

• Utilized selection index theory to integrate methane production into the existing Dutch breeding goal.
• Incorporated heritability and genetic correlations for methane production with other traits from existing literature.
• Performed power calculations to assess data needs for genomic prediction reliability.

Main Results:

• Including methane production with zero economic value in the breeding goal led to a 13% increase in average daily methane production by 2050.
• However, methane intensity decreased by 13% under the same scenario.
• Assigning economic value to methane production in breeding goals could reduce methane intensity by 24% by 2050.

Conclusions:

• Selective breeding is a valuable tool for mitigating methane emissions in livestock, complementing other strategies.
• Achieving desired breeding impacts requires sufficient reliability in genomic predictions.
• Recording methane data on approximately 100 farms with 150 cows each for two years is necessary for reliable genomic prediction.