| Title: | Review: Reducing enteric methane emissions improves energy metabolism in livestock: is the tenet right? |
| Author(s): | Morgavi DP; Cantalapiedra-Hijar G; Eugene M; Martin C; Noziere P; Popova M; Ortigues-Marty I; Munoz-Tamayo R; Ungerfeld EM; |
| Address: | "Universite Clermont Auvergne, INRAE, VetAgro Sup, UMR Herbivores, F-63122 Saint-Genes-Champanelle, France. Electronic address: diego.morgavi@inrae.fr. Universite Clermont Auvergne, INRAE, VetAgro Sup, UMR Herbivores, F-63122 Saint-Genes-Champanelle, France. Universite Paris-Saclay, INRAE, AgroParisTech, UMR Modelisation Systemique Appliquee aux Ruminants, 91120 Palaiseau, France. Centro Regional de Investigacion Carillanca, Instituto de Investigaciones Agropecuarias INIA, Temuco 4880000, Chile" |
| DOI: | 10.1016/j.animal.2023.100830 |
| ISSN/ISBN: | 1751-732X (Electronic) 1751-7311 (Linking) |
| Abstract: | "The production of enteric methane in the gastrointestinal tract of livestock is considered as an energy loss in the equations for estimating energy metabolism in feeding systems. Therefore, the spared energy resulting from specific inhibition of methane emissions should be re-equilibrated with other factors of the equation. And, it is commonly assumed that net energy from feeds increases, thus benefitting production functions, particularly in ruminants due to the important production of methane in the rumen. Notwithstanding, we confirm in this work that inhibition of emissions in ruminants does not transpose into consistent improvements in production. Theoretical calculations of energy flows using experimental data show that the expected improvement in net energy for production is small and difficult to detect under the prevailing, moderate inhibition of methane production ( approximately 25%) obtained using feed additives inhibiting methanogenesis. Importantly, the calculation of energy partitioning using canonical models might not be adequate when methanogenesis is inhibited. There is a lack of information on various parameters that play a role in energy partitioning and that may be affected under provoked abatement of methane. The formula used to calculate heat production based on respiratory exchanges should be validated when methanogenesis is inhibited. Also, a better understanding is needed of the effects of inhibition on fermentation products, fermentation heat, and microbial biomass. Inhibition induces the accumulation of H(2), the main substrate used to produce methane, that has no energetic value for the host, and it is not extensively used by the majority of rumen microbes. Currently, the fate of this excess of H(2) and its consequences on the microbiota and the host are not well known. All this additional information will provide a better account of energy transactions in ruminants when enteric methanogenesis is inhibited. Based on the available information, it is concluded that the claim that enteric methane inhibition will translate into more feed-efficient animals is not warranted" |
| Keywords: | Animals *Livestock/metabolism Methane/metabolism Ruminants/metabolism *Microbiota Fermentation Energy Metabolism Rumen/metabolism Feeding systems Hydrogen flows Metabolisable energy Methanogenesis inhibitor Ruminant; |
| Notes: | "MedlineMorgavi, D P Cantalapiedra-Hijar, G Eugene, M Martin, C Noziere, P Popova, M Ortigues-Marty, I Munoz-Tamayo, R Ungerfeld, E M eng Review England 2023/06/02 Animal. 2023 Jul; 17 Suppl 3:100830. doi: 10.1016/j.animal.2023.100830. Epub 2023 Apr 28" |
