POSTPARTUM MANAGEMENT

Postpartum management is a crucial stage in the cow’s reproductive cycle, significantly influencing the timing of ovulation and subsequent pregnancy outcomes [196]. Critical physiological events, including uterine involution and metabolic adaptation, occur predominantly within the first 3–6 weeks postpartum, representing a window where timely interventions are most effective [197]. Implementing a uterine health program and transitional cow management during this period is essential to prevent delayed ovulation [175]. Delayed ovulation is generally considered physiological within the early postpartum period (up to ~20–30 days in milk), but it becomes pathological if the first ovulation fails to occur beyond approximately 40–60 days in milk, depending on production system, metabolic status, and uterine health.

Uterine health programs are designed to accelerate involution and prevent subclinical and clinical infections that disrupt ovarian function [36]. Postpartum infections, such as endometritis or metritis, increase secretion of proinflammatory cytokines (IL-1β, IL-6, and TNF-α) and prostaglandins, which suppress GnRH and LH release, delaying ovulation [150]. Routine monitoring through palpation, ultrasonography, and cytology or neutrophil scoring allows early detection within the critical postpartum window [198]. Integrating uterine health scoring (e.g., vaginal discharge score, ultrasonographic uterine involution, endometrial PMN%) with ovarian monitoring (follicle size, persistence, and CL formation) enables differentiation between delayed ovulation secondary to uterine pathology versus primary endocrine–metabolic causes. Interventions, including selective antibiotic therapy or prostaglandin administration for regression of pathological corpora lutea, help restore uterine health and support timely ovulation [199].

Management of transitioning cows involves careful nutritional, metabolic, and environmental strategies during the three weeks prepartum and three weeks postpartum, when cows are most susceptible to NEB [200]. NEB during this critical window reduces IGF-1, insulin, and glucose levels, impairing follicular maturation and ovarian responsiveness to LH [201]. Management strategies include providing a balanced diet with adequate energy and protein, supplementing essential micronutrients such as selenium, zinc, and vitamin E, and monitoring BCS to prevent excessive fat mobilization [183]. Optimizing housing, ventilation, and heat abatement during this period further supports endocrine recovery and ovulatory competence [42].

By aligning postpartum timelines, uterine health scores, and ovulation monitoring within this critical early lactation window, practitioners can distinguish between physiological and pathological delayed ovulation, allowing timely interventions that improve reproductive efficiency [3]. Systematic uterine health programs and optimized transition cow management accelerate first postpartum ovulation, reduce the incidence of delayed ovulation, and increase the likelihood of successful conception, thereby enhancing herd level productivity [11].