Selection tools for the control of gastrointestinal parasitism in small ruminants. [French]Original Title La selection genetique pour la maitrise des strongyloses gastro-intestinales des petits ruminants.

摘要

The sustainability of tropical and extensive temperate farming systems is the key for a balance between the environment (soil, fauna and flora) and animal and plant productions. The restoration or preservation of such a trophic and ecological balance requires the implementation of innovative techniques. It is vain to avoid constraints in animal rearing and wiser to choose animals for their adaptations to these constraints. In this context, gastrointestinal strongyle infections are a major constraint in small ruminants, particularly in the humid tropics. In recent years, the strategy of pest eradication has evolved to a more logical manipulation of host-parasite equilibrium in grazed systems by implementation of various actions. The genetic resistance of small ruminants to gastro-intestinal strongyle infections is part of this new approach and plays a major role. The objective of this review was to highlight the contributions of quantitative genetics and genomics to the understanding and exploitation of the differences between individuals for resistance to gastrointestinal strongyle infections. Local breeds are found, in most cases, to be the most resistant and more productive in their environment. Genetic variability exploitable in selection is known in sheep as in goats with a similar genetic control. However, the underlying biological mechanisms are more basic and less efficient in goats. The genomic information accumulates but remains difficult to exploit by professionals.