Conservation of goat populations from southwestern Europe based on molecular diversity criteria

Abstract

Goat farming plays a key role in agricultural activity and in maintaining forest lands in Southwestern Europe . Remarkably, the Iberian Peninsula represents nearly 25% of the European goat census. Goat husbandry is often associated with low input production systems and uses selective breeding programs, which are less advanced than those employed in other livestock. Native goat breeds are very well adapted to produce in marginal areas under extensive conditions. Loss of their genetic diversity could have important economic, ecological and scientific implications as well as social consequences. Several methodologies have been developed to preserve the genetic diversity of single populations, but additional problems arise when a group of breeds, i.e., subpopulations, is considered in conservation programs. The conservation priority of a breed depends on its contribution to the overall genetic diversity of the species, in terms of the intrinsic genetic variation that it harbors and also of its relationship with other breeds. However, the estimation of the contributions of each of these two components to overall genetic diversity cannot be easily assessed. Besides, conservation goals in the short-term (avoidance of inbreeding) and long-term (adaptation to future environmental changes) should be considered when taking conservative decisions. A comprehensive analysis of Iberian goat breeds has been carried out to evaluate conservation priorities based on methodologies that account for within- or between-breed genetic diversity, or combinations of both. Based on genetic distinctiveness, breeds such as Palmera, Formentera, and Blanca Celtibérica were prioritized, whereas the maximum priority was assigned to Florida, Pirenaica, Retinta, and Moncaína breeds when focusing on within-breed diversity. Overall, combined approaches showed very little variation among breeds reflecting a history of extensive gene flow, partly due to transhumance and recent divergence. The main conclusion of our study is that these statistical analyses are useful, but conservation decisions must take into account other factors in addition to strict genetic diversity classification.