Seasonal effects on hematological parameters of Senepol and Zebu cattle raised in Vietnam
Seasonal conditions are recognized as important environmental factors influencing physiological and hematological characteristics in cattle raised under tropical climates. The present study aimed to evaluate the effects of seasonal conditions on hematological parameters in Senepol and Zebu cattle raised in Vietnam. A total of 40 clinically healthy cattle, including 20 Senepol and 20 Zebu animals aged between 12 and 36 months, were used in the experiment. Blood samples were collected during both the rainy and dry seasons and analyzed using an automated hematology analyzer. The evaluated parameters included white blood cell count (WBC), red blood cell count (RBC), hemoglobin concentration (HGB), hematocrit (HCT), erythrocyte indices, and platelet-associated parameters. Statistical analysis was performed using a paired-samples t-test at a significance level of P < 0.05. The results showed that seasonal variation significantly influenced several hematological parameters in both cattle breeds. WBC values increased during the dry season, whereas RBC and HGB values tended to decrease. Hematocrit values showed a moderate increase during the dry season. Erythrocyte indices, including MCV, MCH, and MCHC, remained relatively stable across seasons, while RDW-CV and RDW-SD values generally increased during the dry season. Platelet counts decreased, whereas MPV and PDW values showed increasing trends in both breeds. Seasonal hematological fluctuations were observed in both breeds; however, no direct statistical comparisons between breeds were performed. The findings indicate that seasonal conditions can influence hematological characteristics in imported cattle breeds raised in Vietnam and likely reflect normal physiological responses to seasonal environmental variation. These results provide useful reference data for health monitoring, veterinary assessment, and management strategies for imported cattle raised under tropical climatic conditions.