A simulation model of a dairy forage system to evaluate feeding management strategies with spring rotational grazing

Abstract

To counteract a decrease in the availability of grazing for feeding dairy cows in France, a simulation model is proposed in the paper, which combines decision and agronomic submodels to study forage system management strategies compatible with spring grazing use. Nine strategies were tested with the model using a sequence of 16 climatic years. Three of these strategies come from a survey in south‐west France and six others were designed with research scientists or farm advisors. The strategies differ in the duration of maize silage feeding, the area dedicated to maize silage and the area dedicated to grass silage. Results from simulation models show that the consequence of a large and constant maize silage area is a high maize silage overstock if there is an early turnout or a high grass silage overstock if turnout is late. The consequence of a low maize area is a high grazing duration combined in some years with feeding shortages. Strategies that have no feeding shortage and a low level of maize and grass silage overstock have a high grazing duration and have no constant maize or grass silage areas. The solution proposed to avoid climatic risk, and its consequences on feeding, is based on two procedures: use of reserve areas for production and allowing the production programme to be modified to take into account fresh information, especially weather records.

Management of agricultural wet grasslands for breeding waders: integrating ecological and livestock system perspectives—a review

“…However, reflecting on what influences stocking density from the livestock system perspective is a complex question which cannot be tackled without taking interdependencies among several components of the forage system (pasture, maize and grass silage) into account. Empirical studies in France have emphasised that area allocation (for maize, grass silage, grazed and mowed pastures) and turnout date need to be combined in order to avoid over or under-production of grazing as well as silage surpluses at the annual scale (Coléno and Duru 1999;Coléno et al 2002). Using a simulation model, these authors showed that a turnout date based on the available herbage per hectare can be used to calculate grass area allocation for spring grazing in Fig.…”

L'apport de la gestion de production aux sciences agronomiques. Le cas des ressources fourragères

“…La coordination entre ateliers s'opère donc surtout à l'automne et au printemps. L'adaptation aux aléas est basée sur la variation ex ante des surfaces allouées (surface de provision, Coléno et al, 2002) et ex post de l'utilisation des ressources alimentaires (report de stock de fourrages conservés).…”

Management of grazing systems: from decision and biophysical models to principles for action

“…Providing models and producing strictly biotechnical references does not suffice to deal with the problems posed in types of organisation that differ and to support decisions that are relevant. A similar modelling effort is needed to understand these organisations which form the framework in which decisions are made and actions carried out [15,17]. They therefore require differentiated advice and interventions from researchers and agricultural advisors, leading to a new generation of DSS, less prescriptive and more interactive.…”