Abstract
BACKGROUND: During the transitional period, dairy cows experience oxidative stress and are more susceptible to diseases, including left displacement of the abomasum (LDA). OBJECTIVES: This study aimed to compare oxidative stress biomarker levels in cows with LDA to those in healthy conditions and investigate the associations between predictive metabolites linked to LDA and oxidative stress biomarkers. METHODS: In this case-control study, 400 healthy multiparous Holstein cows were matched for lactation number, milk production and calving date. Blood samples were collected at four time points: 21 and 7 days before, as well as 7 and 21 days after parturition from all animals. During the observation period, seven cows diagnosed with LDA in the main population, and seven healthy cows were randomly selected as controls for the comparison of oxidative stress, liver enzymes and metabolic parameters. Analysis of blood parameters utilized repeated measures ANOVA, and the degree of relationship between oxidative stress biomarkers and other measured parameters was assessed using Pearson correlations. RESULTS: The LDA group exhibited significantly higher levels of urea, blood urea nitrogen (BUN), gamma-glutamyl transferase, glucose, cholesterol, triglyceride (TAG), β-hydroxybutyric acid (BHBA), aspartate aminotransferase (AST), sorbitol dehydrogenase, serum amyloid A (SAA), chloride, sodium, potassium, total antioxidant capacity (TAC) and malondialdehyde (MDA) compared to the control cows (p < 0.05). Positive correlations were observed among BUN, glucose, TB, AST, SAA, BHBA, TAG and MDA. Conversely, these parameters displayed negative correlations with TAC. Negative correlations were found among chloride, sodium, potassium, calcium, phosphorus and MDA, whereas positive correlations were observed with TAC. CONCLUSIONS: These findings highlight the elevated level of oxidative stress and compromised antioxidant defence in cows with LDA and the intricate interplay among oxidative stress, metabolic parameters and liver enzymes.