Seasonal variation in biochemical, molecular and antioxidant profiles of Kajali sheep under heat stress conditions in Punjab

The present investigation evaluated seasonal variations in biochemical, antioxidant, and molecular parameters of stall-fed Kajali sheep, a newly recognized breed for which limited information exists regarding its capacity to withstand heat stress. Exposure to elevated summer temperature resulted in changes in metabolic indicators, including reduced glucose and lipid levels along with increased enzyme activities, reflecting shifts in energy utilization and increased physiological demand, while alterations in renal and protein-related parameters indicated metabolic adjustments associated with thermal stress. Antioxidant status revealed evidence of oxidative challenge through increased lipid peroxidation and reduced enzymatic and non-enzymatic antioxidant capacity, suggesting an imbalance between oxidant production and antioxidant defense. Molecular responses showed increased expression of HSP70, HSP90 and IL-6 during summer, indicating activation of cellular protection and inflammatory pathways, whereas comparatively higher IL-10 expression during winter suggested improved anti-inflammatory regulation under favorable conditions. Although seasonal changes were evident, the measured biochemical, antioxidant and molecular parameters remained within normal physiological limits, indicating effective adaptive regulation. The coordinated adjustment of metabolic activity, oxidative balance and gene expression highlights the ability of Kajali sheep to cope with thermal stress, supporting its suitability for rearing under the climatic conditions of Punjab and its relevance for sustainable local farming systems.