The mule duck : genetic determinism of an intergeneric hybrid

Abstract

The mule duck, an inter-generic hybrid between the Muscovy drake and the common duck, produces more than 90 % of the French “foiegras”. The reciprocal hybrid (common drake x Muscovy female duck) offers no interest in animal breeding. Since the 1980’s, the muleduck has been obtained by artificial insemination, with a fertility rate reaching 70 % owing to artificial insemination practised twice aweek, because of the short duration of the fertile period in the crossbreeding. Thise synthesis first deals with the zoological aspects of thishybridisation (cytogenetics, mating, fertilisation and embryonic development, hybrid sterility). Then, it deals with, from a zootechnicalpoint of view, the reproductive performances of the common duck female (laying, fertility and duration of fertility, hatchability) and thetraits of the mule duck (growth, plumage colouration, behaviour, feed efficiency, body composition, force feeding, quality of the products).The aim was first to describe the specificity of the mule duck with respect to the parental species, and, when possible (the presence of thereciprocal hybrid), to interpret its performances in terms of parental genetic contributions. Another aim was to review the genetic parametersof mule traits estimated within the parental strains and the genetic correlations between purebred and crossbred performances.These parameters determine the potential of within-strain selection to improve the mule duck. At last, some elements of molecular geneticsare presented (genetic markers, compared genetic maps).