Longitudinal blood gas changes and its effects on health and production performance in dairy cows during the transition periodtem

Dairy cows undergo significant metabolic changes during the transition period, which can substantially impact their health and productivity. In this study, we analyzed longitudinal changes in blood gas parameters, plasma physiological indices, and postpartum lactation performance in 46 dairy cows during this critical period.Our results revealed fluctuations in arterial and venous hematocrit, hemoglobin, and oxygen content throughout the transition period, with a notable decline during the late perinatal phase, reaching the lowest levels at 21 days postpartum. In contrast, arterial and venous base excess in extracellular fluid, total carbon dioxide, and bicarbonate concentrations increased, peaking on postpartum day 21. Moreover, among cows with similar milk yields, those with lower blood oxygen levels exhibited higher oxidative stress and inflammation. These findings underscore the crucial role of oxygen metabolism in maintaining health during the perinatal phase. Oxygen insufficiency postpartum appears closely linked to metabolic and physiological disturbances, influencing health traits such as inflammation and oxidative stress.