Background: Hanwoo cattle, an indigenous Korean breed, have become economically significant due to genetic improvements and large-scale farming. As individual cow value increases, understanding their unique physiology across different life stages is crucial for optimal health management. This retrospective study aimed to investigate serum biochemistry differences among non-pregnant, pregnant, and fattening female Hanwoo cattle and establish breed-specific reference intervals (RIs) for accurate health assessment, utilizing data obtained from routine veterinary care. Methods: Blood samples were collected from female Hanwoo cattle, categorized as pregnant (n = 12), non-pregnant (n = 25), and fattening (n = 11). Eighteen serum biochemical parameters were analyzed and descriptive statistics were calculated for each group. The new RIs in different reproductive status of female Hanwoo were established using the Reference Value Advisor program. Results: Significant differences based on reproductive status were identified in blood urea nitrogen (BUN), γ-glutamyl transferase (GGT), triglyceride (TG), glucose (GLU), and creatinine (CRE) levels. BUN, GGT, and TG levels were significantly higher in fattening cattle compared to pregnant and non-pregnant cows. GLU levels increased progressively across pregnant, non-pregnant, and fattening groups, while CRE levels were significantly higher in pregnant cows. Based on values of biochemical parameters, new RI were suggested for sixteen biochemical parameters, encompassing all three reproductive stages. Conclusions: This study established new RIs for female Hanwoo cattle across nonpregnant, pregnant, and fattening stages, providing a more accurate basis for health assessment and management. These findings will contribute to improved individual cow management, supporting genetic improvement efforts, and enhancing overall herd health in female Hanwoo cattle.

Because sows are industrially vital for swine production, monitoring for their health or disorder status is important to ensure high reproductive performance. Especially, ambient temperature changes in different season, especially during summer, are directly influenced to the reproductive performance of sows. Although the serum biochemical parameters are widely applied in the veterinary medicine with wide ranges for the physiological process, the values are also influenced by several factors such as age, breed, gender, and stress. In addition, domestic sows in Koreaspecific reference interval (RI) for serum biochemistry has not been established yet. Therefore, the present study was aimed to evaluate seasonal variation of RIs in the serum biochemistry in domestic sows in Korea at different seasons and to establish normal RIs using a RI finding program (Reference Value Advisor). Significant difference (p < 0.05) on the different seasons were identified in several serum biochemical parameters including BUN, CRE, GGT, GLU, ALB, TP, LDH and Na in sows. Therefore, we further established RIs, specific in domestic sows in Korea regardless of season. The established RIs based on the serum biochemical values provide a baseline for interpreting biochemical results in the domestic sows in Korea, regardless of seasonal effect. It may contribute to develop a strategy for better reproductive performance by improving breeding management practice and evaluating health of pig herds, which facilitate to avert the economic loss in summer infertility in sows.