Heat stress is a critical factor constraining economic efficiency in animal husbandry,particularly in the high-temperature and high-humidity environments of southern regions,where its adverse effects on dairy cow performance,milk yield,reproductive efficiency,and immune function are especially pronounced.Notably,the peak period of heat stress from July to September coincides with a surge in calving numbers,attributable to concentrated breeding activities following the previous year's heat stress period（October-December）and accumulated pregnancies due to reduced conception rates during heat stress. In this context,postpartum uterine care is essential for farm management：（1）it promotes uterine involution,restoring reproductive function and safeguarding fertility potential.（2）it reduces the incidence of retained fetal membranes,metritis,and other disorders,minimizing reproductive failures and production losses.（3）it optimizes reproductive efficiency,ensuring normal estrus-breeding-conception cycles. The dual stressors of heat and parturition further exacerbate uterine health risks,necessitating targeted involution management. From an economic perspective,scientific uterine care not only lowers treatment costs but also significantly enhances farm profitability by improving reproductive performance.

heat stress  /  peripartum period  /  retained fetal membranes  /  metritis  /  uterine involution  /  health regulation