Abstract: This paper reviewed the effects of heat stress on dairy cow reproductive performance and corresponding countermeasures. Heat stress can lead to reduced conception and pregnancy rates,ovulation failure,increased risks of abortion and ovarian cysts,prolonged anestrus periods,decreased milk production,and cumulative damage. Its impact on reproduction includes weakened estrus activity and impaired oocyte and embryo development. To address these issues,measures such as embryo transfer （fresh embryo transfer in summer yields higher conception rates than artificial insemination）,ovulation synchronization techniques （improving conception rates）,reducing embryonic loss （e.g.,administering buserelin after breeding）,preventing and treating metritis （postpartum health protocols）,and managing ovarian disorders （e.g.,using Dinoprostone,buserelin,etc.） can be implemented. Additionally,comprehensive approaches such as heat stress mitigation and nutritional adjustments are essential to enhance dairy cow reproductive efficiency during heat stress.

Key words: heat stress, reproductive disorders, buserelin, early embryonic death