Quantifying the fate of lipophilic contaminants in growing and fattening cattle is the cornerstone for ensuring the chemical safety of beef meat. Exploring the effects of beef cattle feeding and growth physiology on the toxicokinetic of several lipophilic contaminants, including polychlorinated biphenyls (PCBs) requires an integrative approach. Here the mechanistic BeefPOP model is introduced (https://doi.org/10.1016/j.envint.2026.110193). It couples fugacity and physiologically based toxicokinetic concepts with cattle feeding and physiology to simulate PCB kinetics in growing and fattening cattle. The model was optimized and evaluated using data from a toxicokinetic experiment involving Simmental cattle under controlled PCB exposure (https://doi.org/10.1016/j.chemosphere.2022.133951; https://doi.org/10.1016/j.chemosphere.2022.135745). Comparisons of BeefPOP model simulations with toxicokinetic experimental data demonstrated satisfactory predictive performance for adipose tissue PCB concentrations, with deviations below 1.4-fold of the observations. The model showed good accuracy, with mean absolute percentage errors below 20%, and satisfactory adequacy (R² > 0.79). Use of the BeefPOP model underscores the complex interplay between contaminant properties, cattle feeding and growth physiology on PCB toxicokinetics. BeefPOP can support food safety risk management by predicting the fate of lipophilic contaminants in growing and fattening cattle under diverse farming scenarios.