Résumé:
This study was carried out in the wilaya of Relizane, during the period between February 2021 and June 2021, it concerns cows and heifers of the Holstein, Montbéliarde breed, raised on farms under the private sector. in order to assess the zootechnical performance of dairy cows and determine the strengths and weaknesses of the management of dairy cattle with regard to reproduction management, in particular that of heat synchronization reproductive performance and productivity females. the level of fertility and to demonstrate the influence of epigenetics on these parameters.