Preliminary study on the inflammatory response of Spanish native cattle breed during transition period

: Native cows are known for their extraordinary resilience, thanks to a long process of adaptation to specific environmental and management conditions that has shaped their physiological and metabolic traits. Despite the growing interest in these breeds, many biological mechanisms remain largely unexplored. Among these, the peripartum period represents a delicate phase in which the ability to maintain homeostasis is challenged by endocrine and immune adaptations. This preliminary study aimed to investigate the peripartum period in the native Rubia gallega breed by evaluating serum concentrations of cortisol, haptoglobin, leptin, IL-1β, IL-6, and TNF-α. In this study, 15 multiparous cows were enrolled and monitored from -15 to + 15 days before calving. With the exception of leptin (P > 0.05), all parameters investigated were affected by time to calving (P < 0.05). The cows examined showed the highest cortisol concentrations at calving compared to all other observation time points. Haptoglobin levels were significantly higher at -3 days compared to -15 and -7 days, as well as at calving. IL-1β showed a steady increase throughout the pre-calving period, followed by a decrease at calving and a subsequent increase during the post-calving phase. TNF-α concentrations progressively decreased starting at -7 days, continuing this downward trend until the end of the monitoring period. IL-6 increased from -15 days to calving, then decreased at + 7 days. Overall, the picture presented by these preliminary results indicates a transient and well-regulated inflammatory activation that supports the physiological demands of calving and lactation.