UTTAR PRADESH JOURNAL OF ZOOLOGY

Lactation in the indigenous Pandharpuri buffalo (Bubalus bubalis) is a physiologically demanding period characterised by drastic metabolic shifts that generate excess reactive oxygen species (ROS), leading to oxidative stress. This study aimed to evaluate the relative gene expression of major antioxidant genes within peripheral blood mononuclear cells (PBMCs) across non-lactating (dry), early-, mid-, and late-lactation stages. PBMCs serve as effective, minimally invasive sensors for observing systemic physiological status and cellular stress responses. Blood samples were collected from four groups of eight female buffaloes to measure the transcript abundance of Catalase (CAT), Superoxide Dismutases (SOD1, SOD2, SOD3), and Glutathione Peroxidases (GPX1, GPX2, GPX3). Using non-lactating buffaloes as a baseline, the data revealed a highly coordinated, stage-specific antioxidant response. The early-lactation phase emerged as the most oxidatively challenging window, characterised by a massive upregulation of frontline defence genes CAT, SOD1, and GPX1. As lactation progressed, expression patterns shifted; cytoplasmic SOD1 accumulated linearly, peaking during late lactation, while extracellular SOD3 peaked in mid-lactation. In contrast, GPX3 showed an initial early peak but was subsequently downregulated in later stages. These findings indicate that, while acute mitochondrial stress is managed early postpartum, systemic oxidative stress persists heavily into late lactation. Characterising this transcriptomic profile provides critical insights into the metabolic resilience of the Pandharpuri breed and highlights the potential for stage-specific nutritional interventions to mitigate oxidative stress and preserve animal health. This study will help to understand the antioxidant pathway governing the lactational response. Further correlation with oxidative stress markers can be crucial in formulating nutritional strategies to combat oxidative stress during different lactational phases in Pandharpuri buffaloes.