Background: In domestic animal populations, artificial selection and genetic drift are leading to an erosion of genetic diversity. Cryopreserved genetic resources could allow an efficient management of genetic diversity of farm animals by reintroducing lost variants. This study focused on a concrete case of cryopreserved semen use of an ancient bull from the 80's into the breeding scheme of the 2000's in the Abondance breed. Methods: We aimed at describing the genetic contribution of the ancient bull on both genetic diversity and genetic gain using pedigrees and SNP data. We characterized the subsequent impact of this bull on genetic structure of the population. Results: We found that cryopreserved semen restored genetic diversity lost over time. A shift in milk production performance could be absorbed in a few years by reasoned mating choices. The re-use of this old bull had positive impacts integrated into the breeding scheme, such as the contribution of proven genetic originality but also qualities on traits that are less subject to strong selection pressure in the past such as reproductive abilities. Conclusions: The use of cryopreserved semen to manage the genetic variability of animal populations is a possible solution. However, certain aspects need to be carefully monitored to avoid undue disadvantages associated with the provision of genetic originality, notably a discrepancy in the genetic values of selected traits. Therefore, recommendations for the use of the genetic resources available in cryobanks should be put in place in order to enhance the value of all the collections already established and to ensure the sustainability of the selected breeds.