Model-based design of optimal synergetic strategies for methane mitigation with cobenefits for ruminants
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Starting date : 04/11/2024. Funding: Université Paris-Saclay (ADI cotutelle program), CSIC 

This thesis is about exploring strategies to reduce methane (CH4) emissions from ruminants with associated benefits for the animal. CH4 is a greenhouse gas that impacts the environment and its production may represent an energy loss for the ruminant. An optimal CH4 mitigation strategy should also induce co-benefits such as enhanced animal productivity and health.

CH4 is produced by methanogenic Archaea during the fermentation of feeds in the rumen. Rumen fermentation is carried out by the rumen microbiota and mediated by hydrogen (H2) in the rumen ecosystem. H2 is an electron carrier and energy source for the production of CH4. Furthermore, H2 is a thermodynamic driver of rumen fermentation. Reduction of CH4 production can be obtained by using feed additives exerting direct inhibition on the primary pathway of CH4 production of methanogenic Archaea or a promotion of alternative pathways for H2 redirection that result in metabolites that can be used by the animal host as energy source. Combining these two mechanisms into synergetic modulation strategies provides a promising approach to reduce CH4 and, simultaneously, improve rumen function.

The objective of this PhD is to develop mathematical models of rumen fermentation adapted to evaluate synergetic strategies for CH4 reduction. The models will be built on the basis of existing and future data from national and international projects from the partners. The resulting model will be tested and used to design optimal feed strategies with low CH4 emissions and beneficial effects for the animal.