9 research outputs found
Cover crop grazing by sheep: successful partnerships between sheep and arable farmers (DiverIMPACTS Practice Abstract)
Based on the experience acquired by facilitating partnerships, a list of key and optional terms of agreements that support a successful partnership have been drawn up
Genetic diversity and networks of exchange: a combined approach to assess intra-breed diversity
Conservation des ressources génétiques animales en Région wallonne: le paradoxe de l'hyperspécialisation
peer reviewedLes principales races de rente en Région Wallonne se caractérisent par une adaptation à des conditions de production intensive s’extériorisant par des caractéristiques phénotypiques extrêmes telles que l’hypertrophie musculaire (Blanc Bleu Belge, Piétrain, Texel). Le développement de ces races a été essentiellement guidé par une logique économique de spécialisation s’inscrivant dans une tradition agricole wallonne privilégiant le progrès technique. Ce développement s’est accompagné d’un appauvrissement des autres ressources génétiques wallonnes et, au niveau local, il n’existe donc quasi plus d’entre-deux entre « races hyper-spécialisées faisant appel à un système d’élevage intensif » et « races menacées ». Aujourd’hui, la tendance à la diversification des productions se développe et l’éleveur wallon se tourne vers des races importées, essentiellement françaises, pour y répondre (Sunnaert, 2005).The main breed of the waloon regio are adapted to conditions of intensive production with extrem phenotypic experssion
Rapeseed regrowth and white clover cover crop valorisation through sheep grazing (DiverIMPACTS Practice Abstract)
Sheep grazing allows for the valorisation of permanent ground cover while quickly returning nitrogen fixed by WC (up to 100 Kg N ha-1) to the soil. In this way, the carbon: nitrogen balance is maintained below 15, and the nitrogen deficiency risk for the following crop is reduced. Moreover, sheep grazing regulates vole and slug populations. Under such a scheme, there is no more requirement for interventions or inputs between the rapeseed sowing and the winter cereal sowing. From the cropping system perspective, the only additional cost associated with this is the WC seeds cost
Genetic diversity and networks of exchange: a combined approach to assess intra-breed diversity
Abstract Background Cryopreservation of three endangered Belgian sheep breeds required to characterize their intra-breed genetic diversity. It is assumed that the genetic structure of a livestock breed depends mostly on gene flow due to exchanges between herds. To quantify this relation, molecular data and analyses of the exchanges were combined for three endangered Belgian breeds. Methods For each breed, between 91 and 225 sheep were genotyped with 19 microsatellites. Genetic differentiations between breeds and among herds within a breed were evaluated and the genetic structure of the breeds was described using Bayesian clustering (Structure). Exchanges of animals between 20, 46 and 95 herds according to breed were identified via semi-directed interviews and were analyzed using the concepts of the network theory to calculate average degrees and shortest path lengths between herds. Correlation between the Reynolds’ genetic distances and the shortest path lengths between each pair of herds was assessed by a Mantel test approach. Results Genetic differentiation between breeds was high (0.16). Overall Fst values among herds were high in each breed (0.17, 0.11 and 0.10). Use of the Bayesian approach made it possible to identify genetic groups of herds within a breed. Significant correlations between the shortest path lengths and the Reynolds’ genetic distances were found in each breed (0.87, 0.33 and 0.41), which demonstrate the influence of exchanges between herds on the genetic diversity. Correlation differences between breeds could be explained by differences in the average degree of the animal exchange networks, which is a measure of the number of exchanges per herd. The two breeds with the highest average degree showed the lowest correlation. Information from the exchange networks was used to assign individuals to the genetic groups when molecular information was incomplete or missing to identify donors for a cryobank. Conclusions A fine-scale picture of the population genetic structure at the herd level was obtained for the three breeds. Network analysis made it possible to highlight the influence of exchanges on genetic structure and to complete or replace molecular information in establishing a conservation program.</p