Does grazing management provide opportunities to mitigate methane emissions by ruminants in pastoral ecosystems?

Autor: Zubieta ÁS; Grazing Ecology Research Group, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 7712, Porto Alegre, RS 91540-000, Brazil. Electronic address: gello_zuva@hotmail.com., Savian JV; Instituto Nacional de Investigación Agropecuaria (INIA). Programa Pasturas y Forrajes. Estación Experimental INIA, Treinta y Tres. Ruta 8 km 281, Treinta y Tres, Uruguay., de Souza Filho W; Grazing Ecology Research Group, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 7712, Porto Alegre, RS 91540-000, Brazil., Wallau MO; Agronomy Department, University of Florida, 3105 McCarty Hall B, Gainesville, FL 32611, USA., Gómez AM; Grazing Ecology Research Group, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 7712, Porto Alegre, RS 91540-000, Brazil; Facultad de Ciencias Agrarias, Departamento de Producción Animal, Universidad Nacional de Colombia, Medellín, Colombia., Bindelle J; Precision Livestock and Nutrition Unit, Gembloux Agro-Bio Tech, TERRA, Teaching and Research Centre, University of Liège, Gembloux, Belgium., Bonnet OJF; Grazing Ecology Research Group, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 7712, Porto Alegre, RS 91540-000, Brazil., de Faccio Carvalho PC; Grazing Ecology Research Group, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 7712, Porto Alegre, RS 91540-000, Brazil.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2021 Feb 01; Vol. 754, pp. 142029. Date of Electronic Publication: 2020 Aug 31.
DOI: 10.1016/j.scitotenv.2020.142029
Abstrakt: Agriculture, and livestock production in particular, is criticized for being a contributor to global environmental change, including emissions of greenhouse gases (GHG). Methane (CH 4 ) from grazing ruminants accounts for most of livestock's carbon footprint because a large share of them are reared under suboptimal grazing conditions, usually resulting in both low herbage intake and animal performance. Consequently, the CH 4 quota attributed to animal maintenance is spread across few or no animal outputs, increasing the CH 4 intensity [g CH 4 /kg live weight (LW) gain or g CH 4 /kg milk yield]. In this review, the generalized idea relating tropical pastures with low quality and intrinsically higher CH 4 intensity is challenged by showing evidence that emissions from animals grazing tropical pastures can equal those of temperate grasses. We demonstrate the medium-to-high mitigation potential of some grazing management strategies to mitigate CH 4 emissions from grazing ruminants and stress the predominant role that sward canopy structure (e.g., height) has over animal behavioral responses (e.g., intake rate), daily forage intake and resulting CH 4 emissions. From this ecological perspective, we identify a grazing management concept aiming to offer the best sward structure that allows animals to optimize their daily herbage intake, creating opportunities to reduce CH 4 intensity. We show the trade-off between animal performance and CH 4 intensity, stressing that mitigation is substantial when grazing management is conducted under light-to-moderate intensities and optimize herbage intake and animal performance. We conclude that optimizing LW gain of grazing sheep and cattle to a threshold of 0.14 and 0.7 kg/day, respectively, would dramatically reduce CH 4 intensity to approximately 0.2 kg CH 4 /kg LW gain, as observed in some intensive feeding systems. This could represent a mitigation potential of around 55% for livestock commodities in pasture-based systems. Our results offer new insights to the debate concerning mitigation of environmental impacts of pastoral ecosystems.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2020 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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