Over the last few years, France and Wallonia developed an adapted framework for the development of Bleue Mixte (Bleue du Nord in France and the Blanc-Bleu Belge mixed type in Belgium). However, to help livestock breeders preserve these endangered populations, it was crucial to ignore borders and establish a common structure for selection/conservation programmes. The creation of a brand image also improves farm profitability. To foster economic growth for the farms, scientific and technical collaborations were created around a common, rare beef race: the Bleue du Nord/ Blanc-Bleu Belge mixed type. The cross-border group provides a common guideline for the selection. It centralises and interprets the collected data to assess the genetic potential of the animals.