Metabolic assessment of biological mechanisms underlying agroecological systems: The example of parasite dilution and forage niche sharing in mixed-grazing

• DOI: 10.1016/j.agsy.2023.103707
• Publication Date: 2023-06-28T18:44:01Z
• Authors: Frédéric Joly; Pierre Nozière; Philippe Jacquiet; Sophie Prache; Bertrand Dumont
• Keywords: Agroecology; Dilution

Mixed-grazing by sheep and cattle is the simultaneous or sequential grazing of a pasture two species. It an agroecological practice known to improve lamb liveweight gains through parasite dilution (PD) and/or forage niche sharing (FNS). We assessed combined relative strengths mechanisms developing metabolic approach (French uplands context). used recently published equations model infection cost gastrointestinal nematodes in metabolizable energy (ME), crude protein (CP). By comparing levels mixed monospecific grazing, we quantified PD ME CP. also feed value tables assess CP resulting from FNS diet improvement. interpreted these light requirements lambs. applied this dataset mixed-grazing experiment, involving sheep/cattle without veterinary treatment. it generic situation where studied CP, along gradients increasing strength FNS. The our experimental data revealed that i) can represent 100% 57% ii) reduce costs 23% 12%, respectively iii) was more important than terms gains, whereas opposite true for However, meeting less constraining on grassland type, which puts into perspective importance gains. With approach, most modelled situations identified as main gain (79%), (70%), with same observation were difficult meet. Both approaches suggest context, matters often mixed-grazing, due greater difficulty requirements. proposed novel roles biological contrasting nature, help common metrics. This made possible evaluate their strength. has potential understanding impact interacting involved systems, identify prominent ones.