Reproductive impacts and disease burden of metritis and placental retention in dairy cows: A longitudinal monitoring study in Southern Vietnam (2022-2024).

Background and aim: Postpartum reproductive disorders, particularly metritis and placental retention, significantly compromise dairy herd productivity and calf viability. In Vietnam, where dairy production is expanding, limited data exist on the prevalence and consequences of such disorders under modern farm conditions. This study aimed to determine the prevalence of metritis and placental retention in dairy cows on an industrial farm in southern Vietnam from 2022 to mid-2024 and to evaluate their reproductive and neonatal health consequences.

Materials and methods: A longitudinal study was conducted on a dairy herd monitored through skin conductance responses activity sensors and DataFlow™ II software (Allflex Livestock Intelligence, MSD Animal Health Intelligence, USA). Health alerts triggered clinical examinations to identify genital infections. Metritic cows were treated using antibiotics and hormonal therapies and were monitored for recovery and subsequent breeding success. Neonatal calves were examined for respiratory and gastrointestinal disorders for 21 days post-birth. Statistical analysis was performed using Chi-square tests at a 95% confidence level.

Results: Genital infections affected 23.5%-38.8% of cows annually, with metritis prevalence ranging from 7.2% to 9.8%. Placental retention remained consistent at approximately 13% across years. Quarter 2 consistently exhibited the highest incidence of reproductive disorders. Treatment success for metritis was high (85.8%-88.6%); however, post-treatment pregnancy rates declined over time (68.5% in 2022 and 54.8% in 2024). Neonatal respiratory infections (2.9%-4.4%) were more frequent than gastrointestinal infections (0.1%-0.8%), with calf mortality declining from 3.4% in 2022 to 0.7% in 2024.

Conclusion: Metritis and placental retention remain prevalent challenges in Vietnamese dairy herds, adversely impacting reproductive efficiency and calf health despite high treatment efficacy. The seasonal spike in disease incidence underscores the need for tailored herd health management during hotter months. Although early detection through precision monitoring improved recovery outcomes, residual effects on fertility persisted. Strengthened periparturient care, postpartum surveillance, and colostrum management are recommended to enhance both maternal and neonatal health outcomes.