Longitudinal blood gas profiling uncovers systemic hypoxia and its consequences for health and production in transition dairy cows

Wu, Fangchao; Fan, Feixiang; Guo, Zhiyao; Che, HaoYu; Wei, ZiHai; Liu, HongYun; Sun, Hui-Zeng; Liu, Jian-xin; Gu, Feng-Fei

doi:.0.0.0

Article

https://doi.org/10.5713/ab.250687 [Accepted] Published online June 1, 2026.

Longitudinal blood gas profiling uncovers systemic hypoxia and its consequences for health and production in transition dairy cows

Fangchao Wu¹

, Feng-Fei Gu^1,*

¹Zhejiang University, Hangzhou, China
²College of Animal Sciences, Xinjiang Key Laboratory of Herbivorous Nutrition for Meat ＆ Milk, Urumqi, China
³Ministry of Agriculture and Rural Affairs Key Laboratory of Dairy Cattles Genetic Improvement in Southern China, Bright Farming Co., Ltd, Shanghai, China

Correspondence: Feng-Fei Gu, Tel: +86-88981341, Email: fengfeigu@zju.edu.cn

Received: 18 September 2025 • Revised: 15 January 2026 • Accepted: 27 May 2026

Abstract

Objective
This study aimed to investigate whether transition dairy cows experience a negative oxygen balance due to increased metabolic demands postpartum, and to assess how this imbalance affects their health and production performance. The goal was to elucidate the longitudinal changes in blood gas parameters and establish links between hypoxic stress and physiological, inflammatory, and productive indicators.
Methods
Ninety Holstein cows were monitored from 21 days before to 49 days after calving, with blood gas parameters, plasma biochemical indices, dry matter intake, and milk production recorded at multiple time points. To assess the impact of hypoxia, cows were further grouped by postpartum hypoxia-inducible factor 1α (HIF-1α) levels into high and low hypoxic stress groups for comparative analysis.
Results
During the transition period, dairy cows exhibited a significant postpartum decline in arterial and venous hemoglobin (Hb), hematocrit (HCT), and oxygen concentration, reaching the lowest levels at 21 days after calving, while CO₂-related parameters such as TCO₂, HCO₃⁻, and BEecf increased. Cows with higher HIF-1α levels (HHS group) showed lower dry matter intake and milk fat concentration, along with higher plasma β-hydroxybutyrate, malondialdehyde, and haptoglobin levels. Furthermore, significant correlations were observed between blood gas indicators and health parameters, including a negative correlation of SAA with Hb and HCT, highlighting the link between impaired oxygen transport and systemic stress responses.
Conclusion
Postpartum dairy cows characterized by decreased oxygen delivery (lower Hb and HCT) and increased oxygen consumption (elevated CO₂-related parameters), leading to systemic hypoxic stress. This imbalance is associated with liver stress, inflammation, oxidative damage, and reduced feed intake and milk production. These findings underscore the critical need for nutritional and management strategies targeting oxygen availability to support health and productivity during the transition period.

Keywords: Dairy cow health; Hypoxia; Hypoxic stress; Peripartum period