Sustainability & efficiency

Factors influencing methane concentration, production and intensity, and genetic parameters estimates in two Spanish dairy sheep breeds.

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Abstract

In the context of climate change, methane (CH4) emissions from livestock farming, mainly due to enteric fermentation in ruminants, are a focus of attention, with many initiatives aimed at mitigating them. Among these, breeding is presented as a valuable strategy, not only because methane traits have been shown to be heritable, but also because the results of animal selection are cumulative and last over time. In this study, we quantified CH4 emission levels in a total of 240 lactating native Spanish dairy ewes (144 Latxa-LTX and 96 Manchega-MNG), and we estimated genetic parameters of this trait as an initial step toward its inclusion as a breeding goal. CH4 and carbon dioxide (CO2) concentrations were recorded directly from the sheep's nostrils using a sniffer gas recording device. Measurements were taken for 5 to 10 minutes, three times a week, for at least four weeks, at different stages of lactation. Methane concentration (ppm CH₄), production (g CH₄/day), intensity (g CH₄/l), and CH₄/CO₂ ratio were used as the phenotypes. An analysis of significant systematic factors on methane emissions was conducted, and genetic parameters were obtained, including genomic information from all animals (Affymetrix Axiom Ovine Genotyping Array), using a REML approach with the BLUPF90+ software suite. Results revealed that year, age and lambing number, feeding type (indoor or grazing), and lactation stage influenced the methane traits. Heritability estimates for methane concentration ranged from 0.04 ± 0.08 in MNG to 0.05 ± 0.05 in LTX. Methane production showed heritability values of 0.08 ± 0.08 in MNG and 0.12 ± 0.07 in LTX. For methane intensity, estimates ranged from 0.06 ± 0.08 in MNG to 0.12 ± 0.06 in LTX, while the CH₄/CO₂ ratio estimates were 0.08 ± 0.06 in both breeds. Repeatability estimates for methane concentration ranged from 0.13 ± 0.05 in MNG to 0.18 ± 0.03 in LTX; for methane production, estimates were of 0.15 ± 0.01 in MNG and 0.21 ± 0.04 in LTX; for methane intensity, estimates ranged from 0.08 ± 0.05 in MNG to 0.15 ± 0.03 in LTX; finally, for CH4/CO2 ratio, estimates were 0.13 ± 0.03 in MNG and 0.18 ± 0.06 in LTX. These preliminary results indicate that methane emission is under genetic control, with heritability and repeatability estimates varying depending on the phenotype and breed. Furthermore, the estimates obtained made it possible to assess the feasibility of including methane emission mitigation as a potential breeding objective. Currently, the collection of samples and the calculation of other phenotypes continue in both breeds, as well as the study of genetic correlations of methane traits with other traits of interest. This will allow us to better define the breeding strategy to be followed.

Keywords: 2026

How to Cite:

Benhissi, H., Caà±adas, G., Garcà­a-Rodrà­guez, A., Goiri, I., Granado-Tajada, I., Medjadbi, M., Pineda-Quiroga, C., Ramón, M., Rubio de Juan, A. & Valdés-Hernández, J., (2026) “Factors influencing methane concentration, production and intensity, and genetic parameters estimates in two Spanish dairy sheep breeds.”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2286928. doi: https://doi.org/10.31274/wcgalp.24170

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