Multivariate hematological and biochemical profiling reveals conserved physiological modules in Brahman- and...

Hematological and biochemical profiling is widely used to evaluate the physiological and health status of cattle; however, most studies interpret blood parameters individually and may overlook coordinated physiological regulation. Multivariate analytical approaches can reveal biologically integrated relationships among blood traits and provide a broader understanding of systemic physiology. Therefore, this study aimed to identify coordinated physiological modules, describe multivariate relationships among hematological and biochemical traits, and quantify breed-related physiological variation in Brahman- and Charolais-crossbred beef cattle reared under tropical smallholder production systems in northern Thailand.

A cross-sectional study was conducted using 97 clinically healthy breeding beef cows comprising 74 Brahman-crossbred and 23 Charolais-crossbred cattle aged 3-6 years. Blood samples were collected from smallholder farms in Phayao, Chiang Rai, and Lampang provinces, Thailand. Hematological and biochemical parameters were analyzed using automated veterinary analyzers. Univariate analyzes were performed to compare breed-specific differences, while multivariate analyzes, including hierarchical clustering, principal component analysis (PCA), correlation heatmaps, and permutational multivariate analysis of variance (PERMANOVA), were applied to determine physiological relationships and breed contributions to overall blood profile variation.

Hierarchical clustering identified six physiologically coherent modules consisting of erythrocyte, platelet, leukocyte, protein metabolism, hepatic enzyme, and renal function traits, demonstrating coordinated systemic regulation rather than isolated parameter variation. PCA showed that the first two principal components explained 31.1% of the total variance and represented erythrocyte-renal and immune-hepatic physiological axes. Substantial overlap in multivariate physiological space was observed between Brahman- and Charolais-crossbred cattle. PERMANOVA indicated a statistically significant but small breed effect (R² = 0.021, p = 0.028), suggesting that environmental and management factors exerted greater influence on physiological organization than breed background. Breed-related differences were primarily associated with monocyte indices, erythrocyte distribution indices, albumin, and hepatic enzyme activity.

This study demonstrated that hematological and biochemical traits in tropical crossbred beef cattle are organized into conserved physiological modules reflecting integrated systemic regulation. The findings support the application of modular blood profiling as a practical and biologically meaningful approach for herd health monitoring and resilience assessment in tropical smallholder production systems.