K. N. Narozhnykh, M. A. Barsukova
Novosibirsk State Agrarian University, Novosibirsk, Russia
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Volume 26 No. 2
Date of paper submission: 23.10.2025, date of review: 11.11.2025, date of acceptance: 17.12.2025.
Published: 02/28/2026
Abstract. Early forecasting of growth potential is a key factor in improving beef production efficiency. Despite the proven effectiveness of genetic breeding, the metabolic status of an animal can be a limiting factor in realizing its productive potential. The purpose of this study was to identify hematological and biochemical biomarkers at an early age associated with the growth of heifers of beef cattle before weaning, and to develop a robust, validated prognostic model for live weight at weaning. Methods. The study was conducted on a group of Hereford breed heifers (n = 46). Blood samples were taken during weaning for comprehensive hematological and biochemical analysis. Live weight at weaning (at 205 days) and data on the productivity of their mothers were recorded. A multiple linear regression model was built using the step-by-step reverse sampling method based on the Akaike Information Criterion (AIC). The final model underwent a rigorous diagnostic test for the normality of the residue distribution (Shapiro – Wilk criterion) and the homogeneity of the variance (Breusch – Pagan criterion). The predictive ability and stability of the model were assessed by cross-validation using the one-by-one exclusion method (LOOCV). The scientific novelty lies in the search for reliable predictors of the live weight of young Hereford cattle at the early stages of rearing. Results. The final regression model was statistically significant (F = 3.241, p = 0.01776) and explained 31 % of the variation in body weight at weaning (adjusted R2 = 0.3095). Three key predictors showed a significant effect: maternal birth weight (4.33 kg per kg; p = 0.006), serum urea concentration (–2.60 kg per mmol/L; p = 0.032) and cholesterol level (2.17 kg per mmol/L; p = 0.047). Diagnostic tests confirmed the model’s compliance with the assumptions of linear regression. Cross-validation demonstrated the robustness of the model, showing a cross-validation R2 of 0.243 and a root-mean-square error (RMSE) of 16.33 kg. The results show that the combination of the mother’s genetic potential (reflected in her own birth weight) and the heifer’s metabolic profile is a strong predictor of growth before weaning. In particular, low levels of urea and high serum cholesterol can be considered as favorable biomarkers of effective growth-promoting anabolic metabolism. This validated model is an objective tool for early identification of physiologically efficient heifers, being a valuable addition to traditional breeding programs in beef cattle breeding.
Keywords: beef cattle, heifers, live weight at weaning, biomarkers, prognostic model, urea, cholesterol, cross-validation
Acknowledgements. The study was carried out on the topic of the state task 2023–2025 “Formation of a breeding herd of the Hereford beef cattle breed with improved productivity using genetic breeding methods”, registration number of research, development and technological works 123120100080-4.
For citation: Narozhnykh K. N., Barsukova M. A. Metabolic biomarkers of Hereford cattle at an early age as predictors of the live weight of heifers at weaning. Agrarian Bulletin of the Urals. 2026; 26 (02): 306‒317. https://doi.org/10.32417/1997-4868-2026-26-02-306-317 (In Russ.)
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