Extensification en élevage ovin viande par agrandissement des surfaces fourragères : résultats zootechniques et économiques de 5 ans d'expérience dans le Massif central nord

• Published in: Productions animales (Paris. 1988) 1997-05, Vol.10 (2), p.141-152
• Main Authors: Brelurut, Alain, Pailleux, Jean-Yves J.-Y., Benoit, M., Lienard, G., Louault, F., de Montard, F.X.
• Format: Article
• Language: fre
• Subjects: Agricultural sciences; Life Sciences
• ISSN: 0990-0632; 1152-5428

The European Union encourages the extensification of grassland on beef and sheep farms to better master production and to avoid reduced land use. Good conditions, however, are necessary to realise extensification in order to maintain a flock's productivity and particularly its economical results, while maintaining control of the natural vegetation. A long term trial (5 years) was undertaken on an INRA experimental farm located in unfavourised area (800 m altitude). On the farm, two identical sheep flocks were managed with a 30% stocking rate (cattle equivalent/ha) difference. The experimental procedures were adapted every year to achieve optimum grass utilisation under both systems. Extensification did not reduce the ewes' performance and it improved the lambs' carcass weight by 6% in spite of a 26% reduction in the consumption of concentrate and a 50% decrease in grass production cost per ewe. The economical balance, over the whole experimental period, favoured the extensive system. The overall gross margin surplus, 3/4 of which was due to input reduction, was sufficient to cover the structural changes induced by extension. The extensive system results were, however more irregular and required better long term planning over several years, particularly for resource management and for stock carry-over. The technical skill required is at least equal to that required for intensive production. This experiment represented a potential means for improving farming methods. Nevertheless, this potential will not be attained unless the farmers receive technical and economic support for the extensive systems such as the grass subsidy- that was established in France in 1993. L’Union Européenne encourage l’extensification des surfaces fourragères dans les élevages bovins et ovins, en vue de maîtriser les volumes de production et éviter la déprise. Mais cette extensification doit être menée dans de bonnes conditions afin de maintenir la productivité du troupeau et surtout ses résultats économiques, tout en conservant en bon état d’entretien les surfaces d’herbe. Un essai de longue durée (5 ans) a été mis en place dans un Domaine de l’INRA situé en montagne (800 m d’altitude), comparant deux troupeaux ovins de même effectif conduits avec une différence de chargement de 30 % (en UGB/ha d’herbe). Le protocole de conduite a été ajusté chaque année pour aboutir à la meilleure utilisation possible des surfaces de chacun des systèmes. L’extensification n’a pas entraîné de réduc