Heat stress affects dairy cow health status through blood oxygen availability

Journal of Animal Science and Biotechnology

Research

Huizeng Sun¹  Jianxin Liu¹  Jia Zeng¹  Diming Wang²  Hongyun Liu²  Jie Cai² 

[1] Key Laboratory of Dairy Cow Genetic Improvement and Milk Quality Research of Zhejiang Province, College of Animal Sciences, Zhejiang University, Hangzhou, China;Ministry of Education Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou, China;Ministry of Education Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Hangzhou, China;

关键词: Dairy cow;    Health status;    Heat stress;    Lactation performance;    Oxygen metabolism;   

DOI  :  10.1186/s40104-023-00915-3

 received in 2023-03-18, accepted in 2023-07-06,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundRises in global warming and extreme weather occurrence make the risk of heat stress (HS) induced by high ambient temperatures more likely in high-yielding dairy cows, resulting in low milk quality and yield. In animals, oxygen is involved in many physiological and metabolic processes, but the effects of HS on oxygen metabolism remain unclear. Thus, the current study aimed to investigate how oxygen metabolism plays a role in health status of dairy cows by measuring the milk yield, milk composition, and blood biochemical variables of cows under different levels of HS: none (No-HS), mild (Mild-HS), and moderate HS (Mod-HS).ResultsThe HS significantly increased rectal temperature (Ptreat < 0.01) and respiration rate (Ptreat < 0.01). Under Mod-HS, greater Na+ (P < 0.05) and lower total CO2, and pH (P < 0.05) were observed relative to those under No-HS and Mild-HS. Oxygen concentrations in both coccygeal artery and mammary vein (Ptreat < 0.01) were lower under Mod-HS than under No-HS. Coccygeal vein concentrations of heat shock protein 90 (HSP90) (P < 0.05) increased during Mod-HS compared with those in cows under No-HS. Malondialdehyde increased during Mod-HS, and glutathione peroxidase (P < 0.01) increased during Mild-HS. Coccygeal vein concentrations of vascular endothelial growth factor (P < 0.01), heme oxygenase-1 (P < 0.01), and hypoxia-inducible factor 1α (P < 0.01) were greater in cows under Mod-HS than those under No-HS. Red blood cell count (P < 0.01) and hemoglobin concentration (P < 0.01) were lower in the coccygeal vein of dairy cows under Mild- and Mod-HS than those of cows under No-HS.ConclusionsExposure to HS negatively impacts the health status and lactation performance of dairy cows by limiting oxygen metabolism and transportation. However, the specific mechanism by which HS affects mammary function in cows remains unclear and requires further exploration.

【 授权许可】

CC BY   
© Chinese Association of Animal Science and Veterinary Medicine 2023

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