Fertility is poor in dairy cows (e.g.pregnancy rate to a single insemination typically < 40%).Around 40% of embryonic loss occurs during the first week after insemination, making early embryonic mortality a major cause of female infertility.However, molecular regulation of bovine early embryonic development is not well understood.The Chd family of proteins is characterized by the presence of chromodomains (chromatin organization modifier) and SNF2-related helicase/ATPase domains, which alter gene expression by modification of chromatin structure.