Evolution à long terme d'une lande de montagne pâturée par des bovins ou des chevaux. II. Production fourragère

Abstract

Résumé — On a examiné l'évolution des masses végétales, de pâturage de montagne -comportement territorial -comportement alimentaire -cheval de boucherie -Vaccinium myrtillus-Nardus stricta Summary — Long-term evolution of a hill moor grazed by cattle and horses. II. Forage production. The evolution of the plant biomasses, primary production and soil of a disused hill moor was examined during 12 years after introduction of new management. Horses are more efficient than cattle for the elimination of herbaceous or ligneous masses. As a result, the forage offered is more abundant but of lower quality in the case of cattle. The final production is 2.5 t DM/ha/year by horses versus 3.5 by cattle. The soil organic matter evolves best under the areas closely-grazed and stamped by horses. Horses cause local transfers and exhaustions in K, whereas cattle make the K-fertility uniform. According to the animals, the results as a whole, show opposite evolutions of botanical composition and production. The uniform restitution of animal manure due to cattle is necessary for the maintenance or improvement of productivity; the elimination of biomasses in excess due to horses is sufficient for botanical improvement. This raises the question of which of the 2 criteria has to te favored in order to maintain mountain grasslands.hill moor -territorial behairor -feeding behavior -horse -Vaccinium myrtillus -Nardus stricta

Horses and rangelands: perspectives in Europe based on a French case study

“…common reed Phragmites australis ) by smaller and/or soil nutrient‐competitive plants, which consequently enabled a larger number of species to co‐exist (Duncan, ). Similarly, in the upland areas of central France, horses were better than cattle in controll the expansion of low‐nutritive grasses ( Nardus stricta and Deschampsia flexuosa) while promoting the development of medium‐nutritive value grasses ( Festuca rubra and Agrostis tenuis ) (Loiseau and Martin‐Rosset, ). In the same plant community (Martin‐Rosset et al ., ), in sub‐Mediterranean grasslands in Spain (Catorci et al ., ), horses also proved more effective than sheep at controlling dominant unpalatable grasses and improving the pastoral value.…”

“…In a study where Konik horses and Heck cattle of similar body size were grazed at a moderate stocking rate, horses failed to control the invasion of wet grasslands by elderberry ( Sambucus nigra ), whereas cattle succeeded (Vulink et al ., ). Conversely, trampling by horses has been shown to limit the development of Vaccinium myrtillus in the upland area of central France (Loiseau and Martin‐Rosset, ). Efficient reduction of the aerial biomass of gorse was also recorded in Galician Pinus radiata woodlands (Mosquera‐Losada et al ., ; Riguero‐Rodriguez et al ., ), decreasing the fire risk.…”

“…Long stocking periods result in overutilization of preferred vegetation patches (Bailey, ). In the long term, intense grazing pressure on the preferred patches results in plant exhaustion, increase in annuals and reduction of forage productivity (Loiseau and Martin‐Rosset, ). To secure the provision of ecosystem services by horses, technical tools and advice about grazing should be specifically developed for horse owners, taking both their limited agricultural knowledge and the peculiarities associated with mounted horses into account.…”

Déterminants de l’utilisation de la ressource pâturée par le cheval

“…Ainsi leur comportement de choix au pâturage favorise-t-il la création et le maintien d'une hétérogénéité structurale du couvert favorable au moins pendant un temps à la biodiversité prairiale. En situation de pâturage mixte entre chevaux et bovins, la moindre capacité des bovins à exploiter les couverts ras entretenus par les chevaux les conduit à se reporter sur les zones d'herbe haute où ils limitent le développement des espèces les plus compétitives et améliorent la composition botanique (Loiseau et al 1989, Loucougaray et al 2004. Par ailleurs, l'introduction de chevaux avec les bovins après un pâturage bovin permet une plus forte régression des graminées de qualité fourragère médiocre et un meilleur développement des graminées de bonne qualité fourragère (Loiseau et Martin-Rosset 1988).…”

Caractéristiques de la conduite des troupeaux allaitants en zones difficiles

“…Les bovins, qui ont une capacité d'ingestion plus élevée, exercent un tri moindre que les brebis, et les juments prélèvent une ration presque représentative du tapis végétal offert. Le comportement de tri est plus marqué dans les 3 espèces sur des végétations hétérogènes (Loiseau et Martin-Rosset, 1989), mais les différences de comportement se maintiennent.…”